121-33-5 Usage
Summary
Vanillin is the artificial synthesis of the first kind of flavor, synthesized by the German M. Harman, and G-Dr. Twyman in 1874. Usually It is divided into methyl vanillin and ethyl vanillin.
1. Methyl vanillin: white or slightly yellow crystalline, with vanilla aroma and rich milk fragrance, is the largest varieties of perfume industry, is the main ingredients of universal favorite creamy vanilla flavor. Its use is very extensive, such as in food, chemical, tobacco industry as spices, flavoring agent or a flavor enhancer, which is the majority in food consumption of drinks, candy, cakes, biscuits, bread and roasted seeds. There are no relevant reports that vanillin was harmful to the human body.
2. Ethyl vanillin: white to micro yellow needle crystal or crystalline powder, similar to vanilla beans, aroma than methyl vanillin thicker. It is a broad-spectrum flavors, which is one of the world's most important synthetic spice, is an important and indispensable raw material for food additives industry. The aroma is 3-4 times than the vanillin, with aromas of vanilla bean aroma and long-lasting fragrance. Widely used in food, chocolate, ice cream, drinks and cosmetics play aroma and flavour. Also ethyl vanillin also is feed additives, electroplating industry of brightening agent, the pharmaceutical industry of intermediates.
C. Guaiacol glyoxylate route
By using guaiacol and glyoxylic acid as raw material then by condensation, oxidation and decarboxylation made to vanillin.
This method is mainly composed of French Rhone-Poulenc company research and development, and production in large scale. The use of glyoxylic acid from maleic acid methyl ester was prepared by two ozone decomposition (German patent 3224795).
The synthetic route has the advantages of wide material source, less reaction steps, low cost, less three wastes pollution. Therefore, it is considered to be the most appropriate method.
Vanilla extract
Vanilla is a member of the orchid family, a sprawling conglomeration of some 25,000 different species. Vanilla is a native of South and Central America and the Caribbean; and the first people to have cultivated it seem to have been the Totonacs of Mexico’s east coast. The Aztecs acquired vanilla when they conquered the Totonacs in the 15th Century; the Spanish, in turn, got it when they conquered the Aztecs.
Vanilla is a complex blend of flavour and fragrance ingredients extracted from the seed pods of the vanilla orchid, containing at a guess somewhere between 250 and 500 different flavor and fragrance components. The most important ingredient in this blend is vanillin. However, because of the cost and supply chain variability of natural vanilla, most products that want to impart the aroma of vanilla do not in fact use vanilla but rather synthetic vanillin (99% of all vanillin consumed worldwide) made primarily from petrochemicals or chemically derived from lignin.
Vanillin is mainly used as a flavouring agent, primarily in foods and beverages such as chocolate and dairy products, but also to mask unpleasant tastes in medicines or livestock fodder. It is also an intermediate in the manufacture of certain pharmaceuticals and agrochemicals.
Vanillin and vanilla extracts have an estimated annual total volume of 16,000 metric tonnes, worth some USD 650 million in total. Natural vanilla extract represents less than 1% by volume, though it is more important in terms of value. Sales prices range from about USD 1,500 per kg for natural vanilla extract to USD 10-20 per kg for synthetic vanillin.
The primary market opportunity is in providing a competitively priced product, with good aroma properties, made from a natural and sustainable source. Evolva believes such properties will allow fermentation-derived vanillin to be used in a wide variety of food and other products. Evolva does not believe that such a product will significantly replace vanilla obtained from the orchid.
Important spices
Vanillin is commonly known as vanilla powder, cloud Nepal with powder, vanilla extract, is extracted from the Rutaceae vanilla bean, is a kind of important spices, is one of synthetic fragrances yield the largest varieties, mixing chocolate, ice cream, chewing gum, pastry and tobacco essence of important raw materials. Naturally occurring in pods of vanilla planifolia, and clove oil, oakmoss oil, balsam of Peru, tolu balsam storax.
Vanillin has strong and unique vanilla bean aroma, aroma stability, under the high temperature, less volatile. It is vulnerable to light, and gradually oxidized in the air, easy to change color at encountering alkali or alkaline material. Aqueous solution reacts with ferric chloride to produce blue purple solution. Can be used for many fragrance formulas, but mainly used for edible essence. Especially widely used in the candy, chocolate, soft drinks, ice cream, wine, and in the smoke flavor.There is no restrictions imposed on the use of IFRA. But because of easy cause discoloration, we should pay attention to use in white fragrant product.
Vanillin is also an important foundation for edible spices, spices, almost all flavors, most used in food industry. Food flavors are widely used in bread, butter, cream and brandy etc. The addition amount of cakes, biscuits is 0.01~0.04%, candy is 0.02~0.08%, which is one of the most the baked food with spices, can be used for chocolate, biscuit, cake, ice cream and Boudin. Before use, it is dissolved in warm water, the effect is much better. The highest amount of baked food is 220mg/kg, chocolate is 970mg/kg. As fixative agent, coordination agent and modifier are widely used in cosmetics, also is the important flavoring agent for food and drink. it is used in medicine. L-DOPA (L-dopa), methyldopa. Also used for nickel, chrome metal plating brightener.
Physicochemical properties
Vanillin has strong and unique vanilla beans, naturally found in vanilla and clove oil, oil, oakmoss, balsam of Peru, and the rest of tolu balsam. Sulfite solution or red pulp softwood lignin sulfonate, under the alkaline conditions, reacted by high-pressure oxidation hydrolysis precipitation to get white to light yellow crystalline powder or acicular crystal. From petroleum ether precipitation can also generate tetragonal crystal. It has Aroma, Bitter sweet. In the air, it is gradually oxidized. In case of light, it generated decomposition. In case of alkali, it generated discoloration. The relative molecular mass is 152.15. The relative density is 1.056. melting point is different form tetragonal crystalline to another, tetragonal crystal is 81 to 83℃. Acicular crystal ranged from 77 to 79℃, the boiling point is 285℃ (in CO2 gas), 170℃ (2 x 103Pa), 162℃ (1.33 x 103Pa), 146 C (0.533 x 103Pa). It can generate sublimation without decomposition. The flash point is162 ℃. Slightly soluble in cold water, soluble in hot water, soluble in ethanol, ethyl ether, propylene Ketone, benzene, chloroform, carbon disulfide, glacial acetic acid, pyridine and volatile oil. Water and FeCl3 generate blue purple solution. For rats, by oral LD 50 1580mg/kg, mice is by percutaneous LD 50 1500mg/kg.
Industrial production method is that eugenol in the presence of potassium hydroxide, produce to ISO eugenol, then reacted with acetic anhydride formation of isoeugenol acetate, followed by oxidation and hydrolysis reaction to produce. It is an important raw material for mixing chocolate, ice cream, chewing gum the pastry and tobacco flavor. It can also be used as cosmetics fragrance coordination agent and a flavor enhancer. It is also the pharmaceutical raw materials of industry.
In recent years, it appeared a new fashion in the commodity of vanillin. Use oil of clove or basil oil provided out of eugenol as raw material, vanillin obtained by isomerization and oxidation, as it can be regarded as a natural equivalent quality, therefore it is called natural vanillin and into the spice market, its price is about 5 times that of the synthetic product.
Action and use
Flavors: vanillin is edible flavouring agent, with vanilla bean aroma and strong desire for milk fragrance, is an important and indispensable raw material for food additives industry, widely used in all need to increase milk fragrance flavor flavoring in food, such as cake, cold drinks, chocolate, candy, biscuits, instant noodles, bread and tobacco, flavoring liquor, toothpaste, soap, cosmetics, perfume, ice cream, drinks and cosmetics play aroma and flavour. Also it can be used for soap, toothpaste, perfume, rubber, plastic, pharmaceutical products. It Accord with FCCIV standard.
Side Effects
General Side Effects
Using of vanillin in large quantity(over 30g a time) could lead to headache, nausea, vomiting, difficulty breathing, and even kidney damage.Don’t get too frightened, vanillin isn’t one of the most toxic food additives you’ll find and in fact usually won’t trigger much more than a headache or allergic reaction in sensitive folks. Usually, switching from artificial vanilla extract to pure vanilla extract is all that is needed to avoid issues. Many connoisseurs of the vanilla bean claim vanillin to be an inferior product to pure vanilla extract anyway. If you’re making an attempt to eat quality food, you probably won’t encounter much vanillin anyway.
Special Groups Precaution
Special groups refer to newborns, children, pregnant and any other applicable vulnerable groups.
There is no evidence that Vanillin could have any negative effects on these vulnerable groups. It should be safe to use Vanillin in food for newborns and pregnant. However, we still recommend consumers to consult professionals before using large quantity of Vanillin for long period in food for newborns or pregnant.
GRAS Affirmation: Yes
Generally recognized as safe(GRAS) is a FDA designation that a specific substance or ingredient is generally considered safe by experts, and so is exempted from the usual Federal Food, Drug, and Cosmetic Act (FFDCA) food additive tolerance requirements. Vanillin is considered safe by FDA according to existing data and granted GRAS status.
Vanitrope
Vanitrope has a strong and enduring clove and vanilla aroma, the aroma intensity is from 16 to 25 times of vanillin. Vanitrope was early developed. in the twenties of the 20th century. Early synthetic route is that safrole oil as raw material, the alcohol solution of potassium hydroxide reacted hot pressing enable to open ring, and then used sodium ethyl sulfate to make the hydroxy ethylation, finally in the ethanol solution with sulfuric acid hydrolysis to obtain the vanitrope. But due to the lack purity of aroma of the product, so it is very little actual application.
In the fifties of the 20th century, it developed from eugenol preparation of vanitrope synthetic route (U. S. patent 2663741), only then can realize the industrial production.
Catechol flavor chemists,successfully developed by more cheap raw materials of pyrocatechol in the Soviet Union in 1960s.
First with allyl chloride to catechol mono alkylation, and the yield is 75%; followed by rearrangement reaction and yield is 35%~38%; then by using ethyl sodium sulfate for single ethylation, yield is 82%. Finally with potassium hydroxide isomerization will get vanitrope, yield is 84%, after recrystallization of the crude product melting point 85.5 to 86℃.
Vanitrope applied in candy, beverage, ice cream and other food flavoring formulations, the FEMA number is 2922. It also can be used in cosmetics and soap fragrance formula. It not only can used as a spice, but also can be used as a synergistic agent and antioxidant.
Former Soviet Union perfumers hold different views of vanitrope aroma properties. They added it to the chocolate and other food flavor. It is found that the goods are not vanillin aroma, so that it cannot in the flavor of food as a substitute for vanillin. But when used for flavoring test of scented soap, found that soap has strong clove and vanilla aroma like it. The differences with vanillin and isoeugenol, vanitrope to alkali, light, oxidation is very stable, soap like storage does not change color. Therefore vanitrope should be used in fragrance formulations, particularly appropriate for fantasy flavor.
Industrial production methods vanillin
Industrial production of vanillin has more than 100 years of history, people have studied the ways and methods of many synthetic preparations, but the application in a large-scale industrial production are mainly the following three methods.
A. lignin route
In papermaking industry, sulfite pulp waste liquid containing wood lignosulfonates as raw material, the alkaline and high temperature and high pressure was hydrolysis dehydration, and then again oxidation. Canada and the United States mainly adopted the production method of vanillin.
B. Guaiacol formaldehyde route
Guaiacol is the most important raw material for synthesis of vanillin, guaiacol, formaldehyde, the nitroso dimethylaniline as raw material of synthetic route, also known as the nitroso process. The former Soviet Union and China mainly adopts the method.
C. Guaiacol glyoxylate route
By using guaiacol and glyoxylic acid as raw material then by condensation, oxidation and decarboxylation made to vanillin.
This method is mainly composed of French Rhone-Poulenc company research and development, and production in large scale. The use of glyoxylic acid from maleic acid methyl ester was prepared by two ozone decomposition (German patent 3224795).
The synthetic route has the advantages of wide material source, less reaction steps, low cost, less three wastes pollution. Therefore, it is considered to be the most appropriate method.
Content analysis
The method one: UV absorption Spectrophotometry.
Preparation of Standard solution: taking accurately medicines ginseng than vanillin standard about 100mg, into a 250ml volumetric flask, with constant volume with methanol, mixed. The solution 2.0ml, into a 100 ml volumetric flask, with methanol fixed volume mixing.
The liquid sample preparation: weighed accurately sample of about 100mg, the preparation method and the standard solution preparation are the same.
Operation: Take from the solution into a 1 cm quartz cells. Determine absorbance at the maximum absorption wavelength of about 308 nm. Press type calculation sample vanillin (C8H8O3) content (x) (mg):
X=12.5c (Au/As)
C-vanillin in standard solution concentration, g/ml;
Au-The absorbance of sample liquid;
As-The absorbance of standard solution.
Methods two: Accord by gas chromatography (GT-10-4) with non-polar column determination method.
Toxicity
LD50 orally in rats, guinea pigs: 1580, 1400 mg/kg (Jenner)
Limited use
FEMA (mg/kg): soft drinks 63; cold 95; candy 200; baking food 220; pudding class 120, chewing gum, 270; chocolate 970; decorating layer 150; margarine 0.20; syrup 330~20000.
According to the provisions of FAO/WHO:
The allowable amount is 70mg/kg for fast food, of canned baby foods and cereals (1992).
Industry development
China is a big country of world vanillin export, the domestic demand was 2350 tons in 2002, accounted for 30% production, 70% of the remaining was for export. In 1988 only exported 2.73 tons, 1700 tons in 1993, 4653 tons in 2002. From 1993 to 2002, China's export volume of vanillin grew at an average annual rate of rate of 12%. In North America, Europe, Southeast Asia and other markets enjoy a good reputation.
In 2012, global vanillin demand is about 17500 tons, which developed countries demand is in equilibrium state, and developing demand of vanillin increased significantly, making the total demand of vanillin still in growth period. The actual total demand of China currently has reached 3000 tons. At present, the per capita amount is still slightly lower than the global per capita use.
Major domestic suppliers of Jiaxing City, China Chemical Co., Ltd. is now the world's largest vanillin professional manufacturer. In 2014, company with an annual output of methyl vanillin is 10000 tons, 2000 tons of ethyl vanillin, which more than 80% of products are for export.
At abroad, there mainly are France Rhodia Inc., Norwegian Bao very company, Ube three vanillin production companies. Among them, Rhodia, France is the world's most famous vanillin production enterprises, annual production capacity is 8000 tons, the distribution device in France and the United States. in addition to the Norwegian company Bao Selig using lignin production of vanillin, domestic and international companies used guaiac wood phenol-aldehyde acid production of vanillin.
Chemical property
White needle crystal, with Fragrant smell. Soluble in water of 125 times, 20 times of ethylene glycol and 2 times of 95% ethanol, insoluble in chloroform.
Uses
Different sources of media describe the Uses of 121-33-5 differently. You can refer to the following data:
1. 1. Used as a flavor, fragrance, pharmaceutical intermediates.
2. It is to obtain the incense powder, bean fragrant spices. Often used in the fragrance foundation with. It is widely used in almost all the flavor that doubles as a combination of such as violet, Cymbidium, sunflower, Oriental flavor. And piperonal, isoeugenol benzyl ether, coumarin, musk and others are set incense, modifier and mixture, can also be used to cover up bad breath. In edible, smoke flavor as well as wide application, but the amount is larger. In vanilla bean type, cream, chocolate, too Princess flavor are need to use spices.
3. Vanillin is China's regulations allow the use of edible spices, as a fixative agent, is the preparation of the main raw material of vanilla flavor. It can also be directly used in biscuits, cakes, candy, drinks and other food flavoring. Dosage according to the normal production needs, generally in the chocolate 970mg/kg; 270mg/kg in chewing gum; 220mg/kg in pastry, biscuit; 200mg/kg in candy; 150mg/kg in condiment~95mg/kg in cold drinks.
4. GB 2760 1996 provisions allow the use of edible spices. Widely used in the preparation of vanilla, chocolate, butter flavor, the amount is up to 25%~30%, or directly used in biscuits, pastries, dosage is 0.1%~0.4%, cold drink is 0.01%~0.3%, candy is 0.2%~0.8%, especially containing dairy products.
5. An important synthetic fragrance, widely used in daily life activities. It is used as food, tobacco and wine with a fine wisely. In the food industry usage amount is large for the preparation of the vanilla, chocolate, butter flavor, the amount is up to 25-30%, directly on a cookie, cake, dosage is 0.1-0.4%, cold is 0.01-0.3%, candy is 0.2-0.8, especially is containing dairy products. It is used for chemical analysis, tests for protein nitrogen heterocyclic indene, phloroglucinol and tannic acid. In the pharmaceutical industry, it is used for production of antihypertensive drug methyldopa, catechols L-dopa medication, and Catalin and diaveridine.
6. Used as a reagent in organic analysis standard.
7. Tests for protein, nitrogen heterocyclic indene, pyrogallol, tannic acid, iron ions. from benzoic acid in the determination of chloride, spices, organic trace analysis determination of methoxy standard.
2. Vanillin is a flavorant made from synthetic or artificial vanilla which
can be derived from lignin of whey sulfite liquors and is syntheti-
cally processed from guaiacol and eugenol. the related product,
ethyl vanillin, has three and one-half times the flavoring power of
vanillin. vanillin also refers to the primary flavor ingredient in
vanilla, which is obtained by extraction from the vanilla bean.
vanillin is used as a substitute for vanilla extract, with application in
ice cream, desserts, baked goods, and beverages at 60–220 ppm.
3. An intermediate and analytical reagent.
4. Pharmaceutic aid (flavor). As a flavoring agent in confectionery, beverages, foods and animal feeds. Fragance and flavor in cosmetics. Reagent for synthesis. Source of L-dopa.
5. The primary component of Vanilla bean extract.
6. Labelled Vanillin. Occurs naturally in a wide variety of foods and plants such as orchids; major commercial source of natural vanillin is from vanilla bean extract. Synthetically produced in-bulk fro
m lignin-based byproduct of paper processes or from guaicol.
Methods of production
1.N N-,dimethylaniline with hydrochloric acid was acidated to salt, with sodium nitrite nitrification out to nitroso-N, N-nitrobine hydrochloride, which with guaiacol and formaldehyde were condensated at 41-43℃. Then, it with benzene extracted. The first distillation with benzene, and then the second distillation, water recrystallization, 50℃ drying to obtain the product. Sulfite pulp waste liquid containing birch cypress structure units of lignin sulfonate, in alkaline conditions oxidation and hydrolysis can be obtained and the raw material consumption (kg/t) guaiacum phenol (98%) in 1460 sodium nitrite 640, N,N-methyl aniline (98%), 974 of hydrochloric acid (30%), 6000 (99%) of 320.
2.The vanilla bean extract.
By theo-aminoanisole by diazonium hydrolysis into guaiacol, in the presence of nitroso dimethylaniline and catalyst, with formaldehyde condensation, or react with chloroform in Catalyzed by potassium hydroxide and after extraction separation, vacuum distillation and crystallization purification. Also available wood pulp waste liquid, eugenol, guaiacol, safrole were made.
3. Using lignin as raw material
Vanillin can be preparation from paper plant sulfite pulping waste liquor containing lignin. General waste liquid contains solid matter 10%~12%, of which 40%~50% is lignin sulfonic acid calcium. The waste liquid is concentrated to 40%~50% solid form, adding NaOH of 25% of lignin amount, and heating to 160 to 175 ℃ (about 1.1~1.2 MPa), air oxidation for 2h, the conversion rate is generally up to 8%~11%. Oxide with benzene extract vanillin, and water vapor distillation method for the recovery of benzene in the oxide with sodium bisulfite to generate sub hydrogen sulfate salt and impurity separated, and then the decomposition of sulfuric acid to vanillin. Finally, it is by vacuum distillation and recrystallization to obtain the product.
Use guaiacol as raw materials
Chloral guaiacol method and trichloro acetaldehyde in the presence of sodium carbonate or potassium carbonate, heating to 27℃ was synthesized through the condensation of 3-methoxy-4-hydroxyphenyl trichloro methyl carbinol, not reaction guaiac wood phenol water vapor distillation removed. In the presence of caustic soda, nitrobenzene as oxidant, heat to 150 ℃ oxidative cleavage of vanillin was obtained; Can also be used Cu-CuO-CoCl2 as catalyst and 100℃ in the air oxidation, after reaction with benzene extraction of vanillin, by vacuum distillation and recrystallization purification so as to obtain the finished product.
Glyoxylic acid method: in glyoxylic acid solution followed by adding guaiacol, sodium hydroxide and sodium carbonate, and at 30 to 33℃ by condensation to 3-methoxy-4-hydroxy phenyl glycollic acid by solvent extraction of guaiacol reaction after adding sodium hydroxide solution, nitrobenzene sulfonic acid and calcium hydroxide in Q presence heated to 100℃ for oxidation and pyrolysis to vanillin. Oxidation products were neutralized with two chlorine ethane extraction of vanillin, crude product by vacuum distillation and recrystallization was finished.
The nitroso process: 30% hydrochloric acid166kg and water 200kg are added into the reaction kettle, cooled to l0℃, dropping two methyl aniline 61.5kg in 2h the temperature is less than 25%, then continue stirring 20min. water solution is cooled to 6 ℃ after infusion of sodium nitrite 75kg with 25% water solution, the temperature control and continue to stir 1h. filter p-nitroso two methyl aniline hydrochloride at 7~10 ℃, adding a quantitative Ethanol and concentrated hydrochloric acid, diluted in solid, the nitroso two methyl aniline.
Guaiacol and p-nitroso two methyl aniline condensation: The 26kg of urotropine dissolved in 34kg water mixture, then add 126kg guaiacol and 63kg ethanol, stored in headtank standby. The income of the nitroso dimethylaniline dihydrochloride and ethanol mixture of 550Kg will join the reaction kettle, heating to 28℃ after adding metal salt catalyst, and then heated to 35 to 36 ℃ when dropping guaiac wood phenol mixture (3~3.5h), keeping the temperature in 40 to 43 ℃, drop after adding continue to stirring 1h of reaction. Then add 100kg diluted 40 ℃water, stirring and 15min content in liquid condensation of vanillin should be above 11%.
Use benzene as solvent. the rotary liquid-liquid extraction column continuous countercurrent extraction the above condensation liquid. Benzene extraction fluid contains a large number of hydrochloric acid, water washing, and then alkali neutralization to ph=4; Climbing film evaporator distillation recovery of benzene and water vapor rush steam 1h to remove residual benzene; decompression steam to water and finally in 120 to 150 ℃ (666.6Pa) rapid steaming out crude vanillin, freezing point is 70℃ or so. The crude product was dissolved in 70 ℃ in toluene, filtering after cooling to 18 to 20℃, suction and washing with a small amount of toluene to vanillin. Then the second vacuum distillation, from 130 to 140℃ (266.6~399.9Pa) fractions and dissolved in dilute ethanol 60~70 ℃, slowly cooled to 16 to 18 ℃, the crystallization (1H). Using the centrifuge filter, and use a little dilute ethanol washing. At the end of 50 to 60 ℃, hot air drying 12 h products. According to guaiacol, the yield can reach more than 65%.
P-hydroxyphenylaldehyde method
Use p-hydroxybenzaldehyde as raw materials, through single bromination, methoxylation reaction to preparate vanillin. In a 250ml flask, added 16g (0.131mo1) of p-hydroxybenzaldehyde and 90ml solvent. After the dissolution of the people 6.8mL (0.131mol) bromine and heated to 40~45℃ and reaction for 6h. Solvent residue and vacuum pumping, boiling water, hot filtering, filtrate cooling crystallization, filtration and drying of white crystalline 3-bromo-4-hydroxy benzaldehyde, the melting point is 123 to 124 ℃, the yield is 90%.
In 250ml flask, join 12g (0.0597mol) of the product, sodium methanol solution of methylmercury 45ml (0.230mol) 28.24%, and 0.2gCuCl, 35mLDMF. In 115 ℃ reaction for 1.5h and pull the solvent, the residue with 18% hydrochloric acid to pH=4~5, and then hot benzene extraction for 3 times, points to water, benzene layer reduced pressure distillation to benzene, coffee colored liquid. Which was dissolved in hot dilute alcohol solution, cooling to separate white crystallization, filtering, and drying to obtain the product of vanillin 8.3g, melting point is 81 to 82 ℃, 99.5% purity yield is 91.1%.
Description
Vanillin is found in many plants, such as the tuber of Rhizoma Gastrodiae (Tian
Ma), the whole herb of Equisetum (Mu Zei), Ulva pertusa (Kong Shi Chun), and
sugar beets, vanilla beans, Peru balsam, and so on .
Chemical Properties
Different sources of media describe the Chemical Properties of 121-33-5 differently. You can refer to the following data:
1. A great variety of vanilla plants bearing the vanilla pods, or siliques, exist. Those mentioned above are the most important
species. Of special value are those cultivated in Mexico, Madagascar, Java, Tahiti, the Comoro Islands and Réunion. The cultivation
of vanilla beans is very long and laborious. The plant is a perennial herbaceous vine that grows up to 25 m in height and needs
suitable supports in order to grow. Fecundation of flowers is performed (November to December) by perforating the membrane that
separates the pollen from the pistil. This is an exacting task requiring skilled hand labor. Natural fecundation occurs when a similar
operation is carried out by birds or insects that perforate the membrane in search of food. After a few months, clusters of hanging
pods (siliques) are formed; these start to yellow at the lower tip from August to September. At this point, the siliques are harvested and
undergo special treatment that develops the aroma. The siliques are placed in straw baskets and dipped into hot water to rupture the
inner cell wall. After a few months, the aroma starts developing. Then the siliques are exuded by intermittent exposure to sunlight (by
alternately covering and uncovering the siliques with wool blankets). When exudation is complete, the siliques are oiled with cocoa
oil to avoid chapping during drying and are finally dried to a suitable residual moisture content. In the final stage of the preparation,
the best quality siliques form a vanilla “brine” that crystallizes on the surface of the bean. Generally, the processing of vanilla bean
takes more than a year. The most important commercial qualities are brined vanilla, bastard vanilla and vanilla pompona. The bean
is the only part used. Vanilla has a sweet, ethereal odor and characteristic flavor.
2. Vanillin has a characteristic, creamy, vanilla-like odor with a very sweet taste.
3. White, crystalline needles; sweetish
smell. Soluble in
125 parts water, in 20 parts glycerol, and in 2 parts
95% alcohol; soluble in chloroform and ether. Combustible.
4. White or cream, crystalline needles or powder with characteristic
vanilla odor and sweet taste.
5. Vanillin is found in many essential oils and
foods but is often not essential for their odor or aroma. However, it does determine
the odor of essential oils and extracts from Vanilla planifolia and Vanilla
tahitensis pods, in which it is formed during ripening by enzymatic cleavage of
glycosides.Vanillin is a colorless, crystalline solid (mp 82–83°C) with a typical
vanilla odor. Because it possesses aldehyde and hydroxy substituents, it undergoes
many reactions. Additional reactions are possible due to the reactivity of the aromatic
nucleus. Vanillyl alcohol and 2-methoxy-4-methylphenol are obtained by
catalytic hydrogenation; vanillic acid derivatives are formed after oxidation and
protection of the phenolic hydroxy group. Since vanillin is a phenol aldehyde, it is
stable to autoxidation and does not undergo the Cannizzaro reaction. Numerous
derivatives can be prepared by etherification or esterification of the hydroxy group
and by aldol condensation at the aldehyde group. Several of these derivatives are
intermediates, for example, in the synthesis of pharmaceuticals.
Physical properties
Appearance: white or light yellow needle crystal or crystal powder, with a strong
aroma. The relative density is about 1.060. Solubility: It is not only soluble in ethanol, chloroform, ether, carbon disulfide, glacial acetic acid, and pyridine but also in
oil, propylene glycol, and hydrogen peroxide in alkaline solution. It can slowly
oxidize in the air, can be unstable under illumination, and should be stored in a dark
condition. Melting point: the melting point is 81°C.
Occurrence
Vanillin occurs widely in nature; it has been reported in the essential oil of Java citronella (Cymbopogon nardus
Rendl.), in benzoin, Peru balsam, clove bud oil and chiefly vanilla pods (Vanilla planifolia, V. tahitensis, V. pompona); more that
40 vanilla varieties are cultivated; vanillin is also present in the plants as glucose and vanillin. Reported found in guava, feyoa fruit,
many berries, asparagus, chive, cinnamon, ginger, Scotch spearmint oil, nutmeg, crisp and rye bread, butter, milk, lean and fatty fish,
cured pork, beer, cognac, whiskies, sherry, grape wines, rum, cocoa, coffee, tea, roast barley, popcorn, oatmeal, cloudberry, passion
fruit, beans, tamarind, dill herb and seed, sake, corn oil, malt, wort, elderberry, loquat, Bourbon and Tahiti vanilla and chicory root.
History
Vanillin is known as one of the first synthetic spices. In the perfume industry, it is
known as vanillic aldehyde. As early as 1858, French chemist Gby (NicolasTheodore Gobley) obtained pure vanillin for the first time by the method of
rectification. Due to less production yield of natural vanillin, it spurred the search
for a chemical synthesis method of vanillin production. In 1874, German scientist M.?Haarman and co-workers deduced the chemical structure of vanillin and discovered a new way to produce vanillin with abietene as the raw material . In
1965, Chinese scientists found that vanillin has antiepileptic effect and accomplished a study on the pharmacology and toxicology of vanillin from edible to
officinal. They also found that vanillin has certain antibacterial activity, making it
a suitable drug formulation for the treatment of skin disease. Vanillin can be used
as intermediate for synthesis of a variety of drugs, such as berberine and antihypertensive drug L-methyldopa, methoxy-pyrimidine, and heart disease drug
papaverine .
Definition
ChEBI: A member of the class of benzaldehydes carrying methoxy and hydroxy substituents at positions 3 and 4 respectively.
Preparation
Commercial vanillin is obtained by processing waste sulfite liquors
or is synthesized from guaiacol. Preparation by oxidation of isoeugenol is of historical
interest only.1) Preparation from waste sulfite liquors: The starting material for vanillin
production is the lignin present in sulfite wastes from the cellulose industry.
The concentrated mother liquors are treated with alkali at elevated temperature
and pressure in the presence of oxidants. The vanillin formed is
separated from the by-products, particularly acetovanillone (4-hydroxy-3-
methoxyacetophenone), by extraction, distillation, and crystallization.
A large number of patents describe various procedures for the (mainly) continuous
hydrolysis and oxidation processes, as well as for the purification
steps required to obtain high-grade vanillin . Lignin is degraded either
with sodium hydroxide or with calcium hydroxide solution and simultaneously
oxidized in air in the presence of catalysts. When the reaction is completed,
the solid wastes are removed. Vanillin is extracted from the acidified
solutionwith a solvent (e.g., butanol or benzene) and reextractedwith sodium
hydrogen sulfite solution. Reacidification with sulfuric acid followed by vacuum
distillation yields technical-grade vanillin, which must be recrystallized
several times to obtain food-grade vanillin.Water, to which some ethanol may
be added, is used as the solvent in the last crystallization step.
2) Preparation from guaiacol: Severalmethods can be used to introduce an aldehyde
group into an aromatic ring. Condensation of guaiacol with glyoxylic
acid followed by oxidation of the resulting mandelic acid to the corresponding
phenylglyoxylic acid and, finally, decarboxylation continues to be a competitive
industrial process for vanillin synthesis.
a. Vanillin from guaiacol and glyoxylic acid: Currently, guaiacol is synthesized
from catechol, which is mainly prepared by acid-catalyzed
hydroxylation of phenol with hydrogen peroxide. In China, a guaiacol prepared from o-nitrochlorobenzene via o-anisidine is also used. Glyoxylic
acid is obtained as a by-product in the synthesis of glyoxal from
acetaldehyde and can also be produced by oxidation of glyoxal with nitric
acid. Condensation of guaiacol with glyoxylic acid proceeds smoothly
at room temperature and in weakly alkaline media. A slight excess of
guaiacol is maintained to avoid formation of disubstituted products;
excess guaiacol is recovered. The alkaline solution containing 4-hydroxy-
3-methoxymandelic acid is then oxidized in air in the presence of a catalyst
until the calculated amount of oxygen is consumed [358]. Crude vanillin
is obtained by acidification and simultaneous decarboxylation of the
(4-hydroxy-3-methoxyphenyl)glyoxylic acid solution.This process has the advantage that, under the reaction conditions, the glyoxyl
radical enters the aromatic guaiacol ring almost exclusively para to the
phenolic hydroxy group. Tedious separation procedures are thus avoided.
b. Vanillin from guaiacol and formaldehyde: An older process that is still in
use consists of the reaction of guaiacolwith formaldehyde or formaldehyde
precursors such as urotropine, N,N-dimethyl-aniline, and sodium nitrite
.
Production Methods
Vanillin occurs naturally in many essential oils and particularly in
the pods of Vanilla planifolia and Vanilla tahitensis. Industrially,
vanillin is prepared from lignin, which is obtained from the sulfite
wastes produced during paper manufacture. Lignin is treated with
alkali at elevated temperature and pressure, in the presence of a
catalyst, to form a complex mixture of products from which vanillin
is isolated. Vanillin is then purified by successive recrystallizations.
Vanillin may also be prepared synthetically by condensation, in
weak alkali, of a slight excess of guaiacol with glyoxylic acid at
room temperature. The resultant alkaline solution, containing 4-
hydroxy-3-methoxymandelic acid is oxidized in air, in the presence
of a catalyst, and vanillin is obtained by acidification and
simultaneous decarboxylation. Vanillin is then purified by successive
recrystallizations.
Indications
It can be used to treat various types of epilepsy and attention deficit hyperactivity
disorder and vertigo.
Composition
In addition to vanillin (approximately 3%), vanilla contains other aromatic principles: vanillin, piperonal, eugenol,
glucovanillin, vanillic acid, anisic acid and anisaldehyde. Although vanillin is associated with the characteristic fragrance of the
plant, the quality of vanilla bean is not associated with the vanillin content. Bourbon beans contain a high amount of vanillin compared
to Mexican and Tahiti beans.
Aroma threshold values
Detection: 29 ppb to 1.6 ppm; recognition: 4 ppm
Taste threshold values
Taste characteristics at 10 ppm: sweet, typical vanilla-like, marshmallow, creamy-coumarin, caramellic
with a powdery nuance.
Synthesis Reference(s)
The Journal of Organic Chemistry, 46, p. 4545, 1981 DOI: 10.1021/jo00335a045
General Description
Certified pharmaceutical secondary standards for application in quality control provide pharma laboratories and manufacturers with a convenient and cost-effective alternative to pharmacopeia primary standards
Air & Water Reactions
Slowly oxidizes on exposure to air. . Slightly water soluble.
Reactivity Profile
Vanillin can react violently with Br2, HClO4, potassium-tert-butoxide, (tert-chloro-benzene + NaOH), (formic acid + Tl(NO3)3). . Vanillin is an aldehyde. Aldehydes are readily oxidized to give carboxylic acids. Flammable and/or toxic gases are generated by the combination of aldehydes with azo, diazo compounds, dithiocarbamates, nitrides, and strong reducing agents. Aldehydes can react with air to give first peroxo acids, and ultimately carboxylic acids. These autoxidation reactions are activated by light, catalyzed by salts of transition metals, and are autocatalytic (catalyzed by the products of the reaction).
Fire Hazard
Flash point data for Vanillin are not available, however Vanillin is probably combustible.
Flammability and Explosibility
Nonflammable
Pharmaceutical Applications
Vanillin is widely used as a flavor in pharmaceuticals, foods,
beverages, and confectionery products, to which it imparts a
characteristic taste and odor of natural vanilla. It is also used in
perfumes, as an analytical reagent and as an intermediate in the
synthesis of a number of pharmaceuticals, particularly methyldopa.
Additionally, it has been investigated as a potential therapeutic
agent in sickle cell anemia and is claimed to have some antifungal
properties.
In food applications, vanillin has been investigated as a
preservative.
As a pharmaceutical excipient, vanillin is used in tablets,
solutions (0.01–0.02% w/v), syrups, and powders to mask the
unpleasant taste and odor characteristics of certain formulations,
such as caffeine tablets and polythiazide tablets. It is similarly used
in film coatings to mask the taste and odor of vitamin tablets.
Vanillin has also been investigated as a photostabilizer in
furosemide 1% w/v injection, haloperidol 0.5% w/v injection, and
thiothixene 0.2% w/v injection.
Pharmacology
Lethal or sublethal doses of vanillin administered orally to anaesthetized rabbits
produced sudden depression of the blood pressure and stimulated respiration (Deichmann & Kitzmiller,
1940). Similar results were obtained in dogs (Caujolle et al. 1953).
Vanillin produced only a small increase in bile output when administered iv to rats (Rohrbach
& Robineau, 1958), and induced some choleretic activity when injected ip into rats in doses of
10-250 mg/kg (Pham-Huu-Chanh, Bettoli-Moulas & Maciotta-Lapoujade, 1968). Injected sc in doses
of 1 mg/day for 4 days into immature female rats, it caused a decrease in the ovarian- and an
increase in the uterine-weight response to exogenous gonadotropic hormone (Kar, Mundle & Roy,
1960). Vanillin had no effect on the nervous system of fish (Bohinc & Wesley-Hadzija, 1956). In
dietary concentrations of 0.05 and 0.1% it had a cariostatic effect in hamsters without impairing
growth (Stralfors, 1967).
Vanillin administered as an aerosol had no effect on normally-functioning isolated perfused guineapig
lungs and did not prevent spontaneous pneumoconstriction (Pham-Huu-Chanh, 1963 & 1964).
It did not act as a cross-linking (tanning) agent for corium and aorta, since in 0.15 M solution
it did not increase the observed in vitro hydrothermal shrinkage temperatures of goat skin and
human, bovine and canine aortae (Milch, 1965). It decreased slightly the déformability of dense
red cell packs (Jacobs, 1965), and in 1-2 mM concentration produced 50-100% inhibition of collageninduced
platelet aggregation in human blood (Jobin & Tremblay, 1969).
Clinical Use
Vanillin tablet has been used in the treatment of epilepsy and has a better therapeutic
effect. Some patients have a minor dizziness response occasionally in the clinic.
Safety Profile
Moderately toxic by
ingestion, intraperitoneal, subcutaneous, and
intravenous routes. Experimental
reproductive effects. Human mutation data
reported. Can react violently with Br2,
HClO4, potassium-tert-butoxide, tert-
chlorobenzene + NaOH, formic acid +
thallium nitrate. When heated to
decomposition it emits acrid smoke and
irritating fumes. See also ALDEHYDES.
Safety
There have been few reports of adverse reactions to vanillin,
although it has been speculated that cross-sensitization with other
structurally similar molecules, such as benzoic acid, may occur.
Adverse reactions that have been reported include contact
dermatitis and bronchospasm caused by hypersensitivity.
The WHO has allocated an estimated acceptable daily intake for
vanillin of up to 10 mg/kg body-weight.
LD50 (guinea pig, IP): 1.19 g/kg
LD50 (guinea pig, oral): 1.4 g/kg
LD50 (mouse, IP): 0.48 g/kg
LD50 (rat, IP): 1.16 g/kg
LD50 (rat, oral): 1.58 g/kg
LD50 (rat, SC): 1.5 g/kg
Synthesis
From the waste (liquor) of the wood-pulp industry; vanillin is extracted with benzene after saturation of the sulfite waste
liquor with CO2. Vanillin is also derived naturally through fermentation.
Metabolism
Early observers noted conversion of vanillin to vanillic acid which was excreted mainly as the free acid, a conjugated ethereal sulphate or glucurovanillic acid (Preusse, 1880). In man, vanillin is broken down by the liver to vanillic acid which is excreted in the urine. Human liver homogenates readily convert vanillin to vanillic acid in vitro (Dirscherl & Brisse, 1966). Endogenous vanillic acid production and excretion in man from body catecholamines amounts to <0.5 mg/day, compared with the normal contribution from dietary sources of about 9 mg/day (Dirscherl & Wirtzfeldt, 1964).
storage
Vanillin oxidizes slowly in moist air and is affected by light.
Solutions of vanillin in ethanol decompose rapidly in light to give
a yellow-colored, slightly bitter tasting solution of 6,6’-dihydroxy-
5,5’-dimethoxy-1,1’-biphenyl-3,3’-dicarbaldehyde. Alkaline solutions
also decompose rapidly to give a brown-colored solution.
However, solutions stable for several months may be produced by
adding sodium metabisulfite 0.2% w/v as an antioxidant.
The bulk material should be stored in a well-closed container,
protected from light, in a cool, dry place.
Purification Methods
Crystallise vanillin from water or aqueous EtOH, or by distillation in vacuo.[Beilstein 8 IV 1763.]
Incompatibilities
Incompatible with acetone, forming a brightly colored compound. A compound practically insoluble in ethanol is formed
with glycerin.
Regulatory Status
GRAS listed. Included in the FDA Inactive Ingredients Database
(oral solutions, suspensions, syrups, and tablets). Included in nonparenteral medicines licensed in the UK. Included in the
Canadian List of Acceptable Non-medicinal Ingredients.
Check Digit Verification of cas no
The CAS Registry Mumber 121-33-5 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 1,2 and 1 respectively; the second part has 2 digits, 3 and 3 respectively.
Calculate Digit Verification of CAS Registry Number 121-33:
(5*1)+(4*2)+(3*1)+(2*3)+(1*3)=25
25 % 10 = 5
So 121-33-5 is a valid CAS Registry Number.
InChI:InChI:1S/C8H8O3/c1-11-8-4-6(5-9)2-3-7(8)10/h2-5,10H,1H3
121-33-5Relevant articles and documents
-
Prager,Tan
, p. 3661 (1967)
-
Stewart
, p. 4531,4533 (1952)
Oxidation of model lignin compounds with peracetic acid under homogeneous catalysis with polyoxometalates
Popova,Beloglazova,Bogolitsyn,Tortseva,Verkholomova,Pokryshkin
, p. 2092 - 2097 (2014)
Oxidation of lignin model compounds with peracetic acid using polyoxometalate manganesecontaining sodium vanadomolybdophosphate Na11[PMo6V5O39Mn(OH)] as a catalyst has been studied. The effect of pH, concentration and nature of the oxidized compound, concentration of the catalyst and peracetic acid, and temperature on kinetics of oxidation and the products composition has been investigated.
Unprecedented oxidative properties of mesoporous silica materials: Towards microwave-assisted oxidation of lignin model compounds
Badamali, Sushanta K.,Luque, Rafael,Clark, James H.,Breeden, Simon W.
, p. 1 - 4 (2013)
The unusual oxidative ability of mesoporous silicas towards oxidation of an important lignin model molecule, 1,2-(4-hydroxy-3methoxy-phenoxy) ethanol, apocynol under microwave irradiation is presented in this work. Mesoporous MCM-41, HMS, SBA-15 and amorphous silica were employed as catalysts in the present study. Different reactivities were obtained for the various silica materials. It was assumed that the substrate conversion and product selectivity were highly influenced by the nature of mesoporous silica materials. Based on the nature of the catalysts and reaction product profile, a plausible mechanism has been proposed.
-
Bu'lock,Walker
, p. 336 (1967)
-
A three-enzyme-system to degrade curcumin to natural vanillin
Esparan, Vida,Krings, Ulrich,Struch, Marlene,Berger, Ralf G.
, p. 6640 - 6653 (2015)
The symmetrical structure of curcumin includes two 4-hydroxy-3-methoxyphenyl substructures. Laccase catalyzed formation of a phenol radical, radical migration and oxygen insertion at the benzylic positions can result in the formation of vanillin. As vanillin itself is a preferred phenolic substrate of laccases, the formation of vanillin oligomers and polymers is inevitable, once vanillin becomes liberated. To decelerate the oligomerization, one of the phenolic hydroxyl groups was protected via acetylation. Monoacetyl curcumin with an approximate molar yield of 49% was the major acetylation product, when a lipase from Candida antarctica (CAL) was used. In the second step, monoacetyl curcumin was incubated with purified laccases of various basidiomycete fungi in a biphasic system (diethyl ether/aqueous buffer). A laccase from Funalia trogii (LccFtr) resulted in a high conversion (46% molar yield of curcumin monoacetate) to vanillin acetate. The non-protected vanillin moiety reacted to a mixture of higher molecular products. In the third step, the protecting group was removed from vanillin acetate using a feruloyl esterase from Pleurotus eryngii (PeFaeA) (68% molar yield). Alignment of the amino acid sequences indicated that high potential laccases performed better in this mediator and cofactor-free reaction.
An immobilised Co(ii) and Ni(ii) Schiff base magnetic nanocatalyst via a click reaction: A greener approach for alcohol oxidation
Bhat, Pooja B.,Bhat, Badekai Ramachandra
, p. 4933 - 4938 (2015)
A Schiff base immobilised nanocatalyst was synthesized via copper catalysed alkyne azide cycloaddition (CuAAC) on a magnetic support. The nanocatalyst exhibited high accessible active sites with a surface area of 76 m2 g-1 for a cobalt complex and 57 m2 g-1 for a nickel complex. A strong interaction between the magnetic support and the Schiff base was achieved by avoiding leaching during the course of reaction. The nanocatalyst efficiently oxidised both primary and secondary alcohols to carbonyl with improved yield in a solventless system rendering a greener approach.
Catalytic nitrobenzene oxidation of lignins
Gogotov,Rybal'chenko,Makovskaya,Babkin
, p. 2854 - 2857 (1996)
Alkaline nitrobenzene oxidation of hardwood and softwood lignins in the presence of redox and phase-transfer catalysts was studied. The selectivity of oxidation of lignins increased by 1.7 to 1.9 times. A possible mechanism of catalysis is discussed.
Process of lignin oxidation in an ionic liquid coupled with separation
Liu, Shiwei,Shi, Zhongliang,Li, Lu,Yu, Shitao,Xie, Congxia,Song, Zhanqian
, p. 5789 - 5793 (2013)
A novel approach has been developed in order to use lignin as a renewable resource for the production of a high added-value aromatic aldehyde. The concept is based on the use of an ionic liquid as a reversible medium coupled with the separation process, which prevents the aromatic aldehyde products from oxidizing and increases their yields. The conversion of lignin reached 100%, and the total yield of the aromatic aldehydes (vanillin, syringaldehyde and p-hydroxybenzaldehyde) was 29.7% in the coupled process. In addition, the mixture of product and IL phase was easily separated, and the IL phase demonstrated good reusability. Hence, a clean and environmentally friendly strategy for overall utilization of lignin and preparation of an aromatic aldehyde is developed.
Continuous-Flow Synthesis of Supported Magnetic Iron Oxide Nanoparticles for Efficient Isoeugenol Conversion into Vanillin
Marquez-Medina, M. Dolores,Prinsen, Pepijn,Li, Hangkong,Shih, Kaimin,Romero, Antonio A.,Luque, Rafael
, p. 389 - 396 (2018)
This work presents the synthesis of iron oxide nanocatalysts supported on mesoporous Al-SBA-15 by using a continuous-flow setup. The magnetic nanomaterials were tested as catalysts in the oxidative disruption of isoeugenol by using hydrogen peroxide as a green oxidant, featuring high activities (63–88 % conversion) and good selectivities to vanillin (44–68 %). The catalytic systems exhibited good magnetic properties when synthesized under continuous-flow conditions at temperatures not exceeding 190 °C. The use of microwave irradiation significantly reduced times of reaction drastically but exerted negative effects on catalyst reusability.
Platinum-containing catalyst supported on a metal-organic framework structure in the selective oxidation of benzyl alcohol derivatives into aldehydes
Tarasov,Kustov,Isaeva,Kalenchuk,Mishin,Kapustin,Bogdan
, p. 273 - 276 (2011)
The platinum catalyst supported on the metal-organic framework structure MOF-5 is usable in the selective oxidation of vanillyl and piperonyl alcohols into the corresponding aldehydes.
Microbial conversion of vanillin from ferulic acid extracted from raw coir pith
Radhakrishnan, Sivaramapillai,Rejani, Chalikkaran Thilakan
, (2020)
Coir pith, an agro-industrial residue, is resistant to natural degradation, and its accumulation causes environmental pollution. Ferulic acid, a precursor of vanillin, was extracted from the raw coir pith by chemical pre-treatment such as alkaline hydrolysis, acidification, and liquid–liquid extraction method. The obtained ferulic acid (1.2 g/50 g) was analysed using high-performance liquid chromatography (HPLC) and used as a substrate for biotransformation by Aspergillus niger to vanillic acid, which, in turn, was fermented by using Phanerochaete chrysosporium to vanillin. The quantity of vanillic acid detected by HPLC on the third day of incubation was 0.773 g/L, while the optimal yield of vanillin on the subsequent third day of incubation was 0.628 g/L. Thus, the chemical extraction of ferulic acid from coir pith ensued bioconversion into vanillin. These products are highly valuable and economical to be used in industries such as pharmaceuticals, health, cosmetics, and neutraceuticals.
Expression and characterization of a 9-cis-epoxycarotenoid dioxygenase from Serratia sp. ATCC 39006 capable of biotransforming isoeugenol and 4-vinylguaiacol to vanillin
Tang, Jiao,Shi, Lei,Li, Lulu,Long, Liangkun,Ding, Shaojun
, (2018)
A 9-cis-epoxycarotenoid dioxygenase gene from Serratia sp. ATCC 39,006 (SeNCED) was overexpressed in soluble form in E.coli. SeNCED showed the maximum activity at 30 °C and pH 8.0, and it was stable relatively at range of pH 5–10 and temperature of 20 °C to 30 °C. SeNCED effectively catalyzes the side chain double bond cleavage of isoeugenol and 4-vinylguaiacol to vanillin. The kinetic constant Km values toward isoeugenol and 4-vinylguaiacol were 18.92 mM and 6.31 mM and Vmax values were 50.73 IU/g and 4.77 IU/g, respectively. Moreover, the SeNCED exhibited an excellent organic solvent tolerance and the enzyme activity was substantially improved at presence of 10% of trichloromethane. The produced vanillin was achieved at an around 0.53 g/L (3.47 mM) and 0.33 g/L (2.17 mM) after 8 h reaction at 4 mM of isoeugenol and 4-vinylguaiacol, respectively, using transformed Escherichia coli cells harboring SeNCED in the presence of trichloromethane.
Benign-by-design preparation of humin-based iron oxide catalytic nanocomposites
Filiciotto, Layla,Balu, Alina M.,Romero, Antonio A.,Rodríguez-Castellón, Enrique,Van Der Waal, Jan C.,Luque, Rafael
, p. 4423 - 4434 (2017)
The current acid-catalyzed conversion of biomass feedstocks yields substantial quantities of undesired by-products called humins, for which applications are yet to be found. This work aims to provide a starting point for valorisation of humins via preparation of humin-based iron oxide catalytic nanocomposites from humins and thermally treated humins (foams) via solvent-free methodologies including ball milling and thermal degradation. The prepared materials were found to be active in the microwave-assisted selective oxidation of isoeugenol (conversions >87%) to vanillin, proving the feasibility to use humin by-products as template/composite materials.
Oxidative cleavage of isoeugenol to vanillin under molecular oxygen catalysed by cobalt porphyrin intercalated into lithium taeniolite clay
Adilina, Indri Badria,Hara, Takayoshi,Ichikuni, Nobuyuki,Shimazu, Shogo
, p. 72 - 79 (2012)
Three types of Co-porphyrin complexes differing in their porphyrin-ring substituents and nonionic or cationic structure were intercalated into lithium taeniolite (LiTN) using a simple cation exchange method. All the intercalated catalysts displayed expanded clearance spaces (in the range of 0.30-0.51 nm) compared with that of the parent LiTN (0.24 nm). The catalysts were applied for the oxidative cleavage of isoeugenol to vanillin with molecular oxygen as the sole oxidant, and the reaction proceeded effectively under mild reaction conditions. The highest vanillin selectivity of 72% was obtained with CoTPyP/TN, which had the widest clearance space among the three Co-porphyrin catalysts. These intercalated catalysts showed high stability during oxidation, enabling their recycling for at least three runs.
Revisiting alkaline aerobic lignin oxidation
Schutyser, Wouter,Kruger, Jacob S.,Robinson, Allison M.,Katahira, Rui,Brandner, David G.,Cleveland, Nicholas S.,Mittal, Ashutosh,Peterson, Darren J.,Meilan, Richard,Román-Leshkov, Yuriy,Beckham, Gregg T.
, p. 3828 - 3844 (2018)
Lignin conversion to renewable chemicals is a promising means to improve the economic viability of lignocellulosic biorefineries. Alkaline aerobic oxidation of lignin has long been employed for production of aromatic compounds such as vanillin and syringaldehyde, but this approach primarily focuses on condensed substrates such as Kraft lignin and lignosulfonates. Conversely, emerging lignocellulosic biorefinery schemes enable the production of more native-like, reactive lignin. Here, we revisit alkaline aerobic oxidation of highly reactive lignin substrates to understand the impact of reaction conditions and catalyst choice on product yield and distribution. The oxidation of native poplar lignin was studied as a function of temperature, NaOH loading, reaction time, and oxygen partial pressure. Besides vanillin and syringaldehyde, other oxidation products include acetosyringone and vanillic, syringic, and p-hydroxybenzoic acids. Reactions with vanillin and syringaldehyde indicated that these compounds are further oxidized to non-aromatic carboxylic acids during alkaline aerobic oxidation, with syringaldehyde being substantially more reactive than vanillin. The production of phenolic compounds from lignin is favored by high NaOH loadings and temperatures, but short reaction times, as the products degrade rapidly, which is further exacerbated by the presence of oxygen. Under optimal conditions, a phenolic monomer yield of 30 wt% was obtained from poplar lignin. Testing a range of catalysts showed that Cu-containing catalysts, such as CuSO4 and LaMn0.8Cu0.2O3, accelerate product formation; specifically, the catalyst does not increase the maximum yield, but expands the operating window in which high product yields are obtainable. We also demonstrate that other native and isolated lignin substrates that are significantly chemically modified are effectively converted to phenolic compounds. Finally, alkaline aerobic oxidation of native lignins was compared to nitrobenzene oxidation and reductive catalytic fractionation, as these methods constitute suitable benchmarks for lignin depolymerization. While nitrobenzene oxidation achieved a somewhat higher yield, similar monomer yields were obtained through RCF and alkaline aerobic oxidation, especially for lignins with a high guaiacyl- and/or p-hydroxyphenyl-content, as syringyl units are more unstable during oxidation. Overall, this study highlights the potential for aerobic lignin oxidation revisited on native-like lignin substrates.
Synthesis of selected aromatic aldehydes under UV-LED irradiation over a hybrid photocatalyst of carbon nanofibers and zinc oxide
Fernandes, Raquel A.,Sampaio, Maria J.,Da Silva, Eliana S.,Serp, Philippe,Faria, Joaquim L.,Silva, Cláudia G.
, p. 286 - 292 (2019)
Zinc oxide (ZnO) prepared by chemical vapor deposition was combined with different amounts of carbon nanofibers (CNF) to obtain hybrid materials, which were thoroughly characterized using several techniques. The photocatalytic performance was evaluated towards the photocatalytic synthesis of vanillin (VAD) starting from vanillyl alcohol (VA). The incorporation of the carbon phase in ZnO (from 5% to 20% wt.) was found to increase the surface area and the photocatalytic performance of the materials. The latter was attributed to the efficient separation of charge carriers generated on the optical semiconductor. With the best performing material, the one containing 10% of CNF, the selectivity of the synthesis towards vanillin generation was increased by a factor of 2.5 compared to previous studies, with the additional advantage of carrying the reaction in aqueous medium. The same photocatalyst was successfully applied to the selective synthesis of other aromatic aldehydes, namely anisaldehyde, piperonal, and benzaldehyde. A relationship between the efficiency of the photocatalytic oxidation of the alcohols and the activating nature of their aromatic ring substituents was proposed.
Solid-supported acids for debenzylation of aryl benzyl ethers
Petchmanee, Thaninee,Ploypradith, Poonsakdi,Ruchirawat, Somsak
, p. 2892 - 2895 (2006)
Solid-supported acids have been investigated for aromatic debenzylation reactions. Stoichiometric amounts of solid-supported acids in refluxing toluene with or without 4 equiv of methanol effectively provided the desired aromatic debenzylation products of various systems in moderate to excellent yields (up to 98%).
Methoxyphenols from burning of Scandinavian forest plant materials
Kjaellstrand, Jennica,Ramnaes, Olle,Petersson, Goeran
, p. 735 - 741 (2000)
Semivolatile compounds in smoke from gram-scale incomplete burning of plant materials were assessed by gas chromatography and mass spectrometry. Gas syringe sampling was shown to be adequate by comparison with adsorbent sampling. Methoxyphenols as well as 1,6-anhydroglucose were released in amounts as large as 10 mg kg-1 of dry biomass at 90% combustion efficiency. Wood, twigs, bark and needles from the conifers Norway spruce and Scots pine emitted 12 reported 2-methoxyphenols in similar proportions. Grass, heather and birchwood released the same 2-methoxyphenols but also the corresponding 2,6-dimethoxyphenols which are characteristic of angiosperms. The methoxyphenols are formed from lignin and differ in structure by the group in para position relative to the phenolic OH group. Prominent phenols were those with trans-l-propenyl and ethenyl groups in that position. Vanillin, 4- hydroxy-3-methoxybenzaldehyde, was a prominent carbonyl compound from the conifer materials. (C) 2000 Elsevier Science Ltd.
-
Hansson,Wickberg
, p. 191 (1976)
-
Liquid-phase oxidation of 2-methoxy-p-cresol to vanillin with oxygen catalyzed by a combination of CoCl2 and N-hydroxyphthalimide
Zhang, Yuecheng,Li, Xiujuan,Cao, Xiaohui,Zhao, Jiquan
, p. 1303 - 1311 (2014)
Liquid-phase oxidation of 2-methoxy-p-cresol to vanillin (4-hydroxy-3-methoxybenzaldehyde), in methanol, with molecular oxygen at atmospheric pressure as oxidant and a combination of cobaltous chloride and N-hydroxyphthalimide (NHPI) as catalyst, has been investigated. The effect of reaction conditions on conversion and selectivity for vanillin was studied systematically. Selectivity for vanillin could be enhanced by optimizing the molar ratio of 2-methoxy-p-cresol to NHPI, the amount of sodium hydroxide, reaction time, reaction temperature, and the volume of methanol, which determined the concentration of the reactants. Under the optimized conditions the yield of vanillin was 90.1 %. Springer Science+Business Media Dordrecht 2013.
Mixed Co-Mn oxide-catalysed selective aerobic oxidation of vanillyl alcohol to vanillin in base-free conditions
Jha, Ajay,Patil, Kashinath R.,Rode, Chandrashekhar V.
, p. 1384 - 1392 (2013)
Manganese-doped cobalt mixed oxide (MnCo-MO) catalyst was prepared by a solvothermal method. The as-prepared catalyst was characterised by X-ray photoelectron spectroscopy, H2 temperature-programmed reduction, O2 temperature-programmed oxidation and XRD. This catalyst gave 62 % conversion with 83 % selectivity to vanillin in 2 hours for the liquid-phase air oxidation of vanillyl alcohol without using base. Three different types of metal oxides were observed in the prepared catalyst, which could be identified as Co3O4, Mn3O4 and CoMn 2O4. Among these, the tetragonal phase of CoMn 2O4 was found to be more active and selective for vanillyl alcohol oxidation than Co3O4 and Mn3O 4. High-resolution TEM characterisation revealed the morphology of MnCo-MO nanorods with a particle size of 10 nm. Successful recycling of the catalyst was also established in this oxidation reaction. It takes two: Mn in the MnCo mixed oxide (MO) forms a metal hydroperoxo complex simultaneously giving the phenolate ion of vanillyl alcohol under base-free conditions, which undergoes smooth air oxidation to give vanillin with >83 % selectivity (see scheme). The high catalytic activity of the MnCo-MO results from a synergic effect of the MO phases, which is absent in single Mn or Co oxides. Copyright
Nickel hydroxide/cobalt-ferrite magnetic nanocatalyst for alcohol oxidation
Bhat, Pooja B.,Inam, Fawad,Bhat, Badekai Ramachandra
, p. 397 - 402 (2014)
A magnetically separable, active nickel hydroxide (Bronsted base) coated nanocobalt ferrite catalyst has been developed for oxidation of alcohols. High surface area was achieved by tuning the particle size with surfactant. The surface area of 120.94 m2 g-1 has been achieved for the coated nanocobalt ferrite. Improved catalytic activity and selectivity were obtained by synergistic effect of transition metal hydroxide (basic hydroxide) on nanocobalt ferrite. The nanocatalyst oxidizes primary and secondary alcohols efficiently (87%) to corresponding carbonyls in good yields.
Selective Aerobic Oxidation of Alcohols over Gold-Palladium Alloy Catalysts Using Air at Atmospheric Pressure in Water
Zhang, Wei,Xiao, Ziqiang,Wang, Jiajun,Fu, Wenqin,Tan, Rong,Yin, Donghong
, p. 1779 - 1788 (2019)
A series of bimetallic Au?Pd alloy nanoparticles (NPs) with varied Au/Pd molar ratios was supported on Gamma-alumina (γ-Al2O3) surface through the co-impregnation-reduction method using HAuCl4 and PdCl2 as metal precursors. Characterization results suggested the high dispersion of Au?Pd alloy NPs, as well as the interplay between the two compositions. Benefitting from the synergistic effects of Au?Pd alloying, the bimetallic Au-Pdx@γ-Al2O3 catalysts were highly efficient for selective aerobic oxidation of various alcohols either aromatic or aliphatic in water using air at atmospheric pressure as a sole oxidant without the need for any cocatalyst. Quantitative yields of corresponding aldehydes or ketones were achieved over Au-Pd1.2@γ-Al2O3 within 2 h, whereas pure Au@γ-Al2O3 or Pd@γ-Al2O3 was far less efficient. More importantly, the “alloying effect” appeared to stabilize the bimetallic NPs against aggregation and poisoning, which made the Au-Pdx@γ-Al2O3 more stable and reusable in the aerobic oxidation of alcohols.
Enhancement of pancreatic lipase inhibitory activity of curcumin by radiolytic transformation
Kim, Tae Hoon,Kim, Jae Kyung,Ito, Hideyuki,Jo, Cheorun
, p. 1512 - 1514 (2011)
The naturally occurring yellow dietary diarylheptanoid curcumin (1) was converted by γ-ray to two new γ-lactones, curculactones A (2) and B (3), as well as four known transformates, erythro-1-(3-methoxy-4-hydroxy-phenyl) -propan-1,2-diol (4), threo-1-(3-methoxy-4-hydroxy-phenyl)-propan-1,2-diol (5), vanillic acid (6), and vanillin (7). The structures of the two new γ-lactone derivatives were elucidated on the basis of spectroscopic methods. The steroisomeric phenylpropanoids 4 and 5 exhibited significantly enhanced inhibitory activity against pancreatic lipase when compared to parent curcumin.
Oxidative cleavage of C-C double bond in cinnamic acids with hydrogen peroxide catalysed by vanadium(v) oxide
Horvat, Monika,Iskra, Jernej
, p. 2073 - 2081 (2022/04/07)
We have developed a cheap, green, mild and environmentally friendly method for the selective cleavage of carbon-carbon double bonds with a 30% aqueous solution of hydrogen peroxide as the oxidant and vanadium(v) oxide as the catalyst. The selectivity of the oxidative cleavage of cinnamic acid derivatives 1 depends on the substituents and the solvent used (DME - MeOCH2CH2OMe, TFE - 2,2,2-trifluoroethanol or MeCN). In DME, p-hydroxy derivatives were selectively converted to benzaldehyde derivatives 2, in TFE, oxidative cleavage led to the formation of benzoquinone derivatives 4, while in MeCN, cinnamic acid derivatives were selectively converted to benzoic acid derivatives 3. Ferulic acid 1a was quantitatively and selectively converted to vanillin 2a in a 91% isolated yield on a gram scale. Dimeric difurandione 1a′ was isolated as an intermediate, which was confirmed by in situ ATR-IR spectroscopy, while the formation of diols or epoxides was not observed. The analogous styrene derivative, 4-vinylguaiacol 1e was also selectively converted to either vanillin 2a or 2-methoxyquinone 4a in a high yield. The green metric for the conversion of ferulic acid to vanillin by different methods was calculated and compared to our method, and showed that our method has better environmental parameters.
Discovery, Biocatalytic Exploration and Structural Analysis of a 4-Ethylphenol Oxidase from Gulosibacter chungangensis
Alvigini, Laura,Fraaije, Marco W.,Gran-Scheuch, Alejandro,Guo, Yiming,Mattevi, Andrea,Saifuddin, Mohammad,Trajkovic, Milos
, p. 3225 - 3233 (2021/10/04)
The vanillyl-alcohol oxidase (VAO) family is a rich source of biocatalysts for the oxidative bioconversion of phenolic compounds. Through genome mining and sequence comparisons, we found that several family members lack a generally conserved catalytic aspartate. This finding led us to study a VAO-homolog featuring a glutamate residue in place of the common aspartate. This 4-ethylphenol oxidase from Gulosibacter chungangensis (Gc4EO) shares 42 % sequence identity with VAO from Penicillium simplicissimum, contains the same 8α-N3-histidyl-bound FAD and uses oxygen as electron acceptor. However, Gc4EO features a distinct substrate scope and product specificity as it is primarily effective in the dehydrogenation of para-substituted phenols with little generation of hydroxylated products. The three-dimensional structure shows that the characteristic glutamate side chain creates a closely packed environment that may limit water accessibility and thereby protect from hydroxylation. With its high thermal stability, well defined structural properties and high expression yields, Gc4EO may become a catalyst of choice for the specific dehydrogenation of phenolic compounds bearing small substituents.
Rapid biosynthesis of phenolic glycosides and their derivatives from biomass-derived hydroxycinnamates
Zhao, Mingtao,Hong, Xulin,Abdullah,Yao, Ruilian,Xiao, Yi
supporting information, p. 838 - 847 (2021/02/09)
Biomass-derived hydroxycinnamates (mainly includingp-coumaric acid and ferulic acid), which are natural sources of aromatic compounds, are highly underutilized resources. There is a need to upgrade them to make them economically feasible. Value-added phenolic glycosides and their derivatives, both belonging to a class of plant aromatic natural products, are widely used in the nutraceutical, pharmaceutical, and cosmetic industries. However, their complex aromatic structures make their efficient biosynthesis a challenging process. To overcome this issue, we created three novel synthetic cascades for the biosynthesis of phenolic glycosides (gastrodin, arbutin, and salidroside) and their derivatives (hydroquinone, tyrosol, hydroxytyrosol, and homovanillyl alcohol) fromp-coumaric acid and ferulic acid. Moreover, because the biomass-derived hydroxycinnamates directly provided aromatic units, the cascades enabled efficient biosynthesis. We achieved substantially high production rates (up to or above 100-fold enhancement) relative to the glucose-based biosynthesis. Given the ubiquity of the aromatic structure in natural products, the use of biomass-derived aromatics should facilitate the rapid biosynthesis of numerous aromatic natural products.
