- Preparation method of natural maltol
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The invention provides a preparation method of natural maltol. The preparation method has the characteristics that methyl metal halide is not prepared and used, 2-furan ethanol is directly prepared through the reduction of natural 2-acetylfuran, and the like. The method is simple in process and easy and convenient to operate, few devices are adopted, the pollution and occupational hazard caused bymethyl halide to air and operators are avoided, and the method is suitable for industrial production.
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- Formation of Reactive Intermediates, Color, and Antioxidant Activity in the Maillard Reaction of Maltose in Comparison to d -Glucose
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In this study, the Maillard reaction of maltose and d-glucose in the presence of l-alanine was investigated in aqueous solution at 130 °C and pH 5. The reactivity of both carbohydrates was compared in regards of their degradation, browning, and antioxidant activity. In order to identify relevant differences in the reaction pathways, the concentrations of selected intermediates such as 1,2-dicarbonyl compounds, furans, furanones, and pyranones were determined. It was found, that the degradation of maltose predominantly yields 1,2-dicarbonyls that still carry a glucosyl moiety and thus subsequent reactions to HMF, furfural, and 2-acetylfuran are favored due to the elimination of d-glucose, which is an excellent leaving group in aqueous solution. Consequently, higher amounts of these heterocycles are formed from maltose. 3-deoxyglucosone and 3-deoxygalactosone represent the only relevant C6-1,2-dicarbonyls in maltose incubations and are produced in nearly equimolar amounts during the first 60 min of heating as byproducts of the HMF formation.
- Kanzler, Clemens,Schestkowa, Helena,Haase, Paul T.,Kroh, Lothar W.
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p. 8957 - 8965
(2017/10/17)
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- Maltol and homolog preparation method by means of molecular oxygen oxidation
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The invention provides a maltol and homolog preparation method by means of molecular oxygen oxidation. The method comprises the following steps of charging, a first-stage oxidation reaction, a second-stage oxidation reaction and hydrolysis. According to the first-stage oxidation reaction, alpha-furyl alcohol is used as a raw material, gas with an oxygen content of 15%-85% is used as an oxidizing agent, a heteroatom molecular sieve and basic resin are used as a composite catalyst in a solvent, and an oxidizing ring opening rearrangement reaction is conducted at the temperature of 50-160 DEG C; according to the second-stage oxidation reaction, the temperature drops to 10-40 DEG C, gas with an oxygen content of 90% or above is pumped in, an epoxidation reaction is conducted, and the temperature of the reaction is kept for 0.5-3 h. According to the method, the production yield reaches 50% or above, and the production yield reaches 67% or above in the condition of optimization; the oxidation reaction conducted by using molecular oxygen has the advantages of energy conservation, low cost and environmental protection, and recycling and application of the catalysts are easier to achieve by means of the composite catalyst made from the heteroatom molecular sieve and the basic resin.
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Paragraph 0028-0032; 0058-0062
(2017/09/26)
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- A process for the separation of methyl maltol
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The invention provides a methyl maltol separating method. Methyl maltol in a methyl maltol crude product and barium hydroxide or barium oxide perform selective reaction to generate barium methyl maltol; after water washing and centrifugal filtration, the barium methyl maltol reacts with sodium sulfate to generate barium sulfate precipitate and sodium methyl maltol; centrifugal filtration is performed again, and a sodium methyl maltol solution and barium sulfate are obtained; the sodium methyl maltol solution is subjected to acidification, crystallization and centrifugal filtration to obtain a methyl maltol solid and a sodium sulfate water solution; and the methyl maltol solid is recrystallized and dried to obtain a finished product, and the sodium sulfate solution is circularly used. According to the method, carbonization and decomposition of methyl maltol due to high-temperature sublimation with a conventional separating method are avoided, and the yield of methyl maltol is increased to be higher than 95% from 85%-88%.
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Paragraph 0042; 0043
(2016/10/20)
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- Investigation of self-immolative linkers in the design of hydrogen peroxide activated metalloprotein inhibitors
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A series of self-immolative boronic ester protected methyl salicylates and metal-binding groups with various linking strategies have been investigated for their use in the design of matrix metalloproteinase proinhibitors.
- Jourden, Jody L. Major,Daniel, Kevin B.,Cohen, Seth M.
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supporting information; experimental part
p. 7968 - 7970
(2011/08/07)
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- STIMULUS-TRIGGERED PRODRUGS
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Set forth herein, inter alia, are compositions and methods for treating diseases with prodrugs. Provided herein are prodrug compositions for inhibiting the function of proteins, compositions and methods for treating diseases associated with oxidative compounds, oxidatively-sensitive prodrugs of inhibitors of metalloproteases. and methods of inhibiting metalloproteases using oxidatively-sensitive prodrugs.
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Page/Page column 54-56
(2012/01/13)
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- Enzymatic activation of a matrix metalloproteinase inhibitor
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Matrix metalloproteinase inhibitors (MMPi) possessing a glucose protecting group on the zinc-binding group (ZBG) show a dramatic increase in inhibitory activity upon cleavage by β-glucosidase.
- Major Jourden, Jody L.,Cohen, Seth M.
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experimental part
p. 1241 - 1243
(2010/06/15)
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- Hydrogen peroxide activated matrix metalloproteinase inhibitors: A prodrug approach
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(Figure Presented) Doing double duty: A metalloproteinase inhibitor that can be activated by reactive oxygen species (ROS) has been designed to protect the blood-brain barrier (BBB) in ischemic reperfusion injury. By both neu-tralizing damaging ROS and inhibiting degradative metalloproteinases, a single compound can eliminate both threats to the BBB upon activation.
- Major Jourden, Jody L.,Cohen, Seth M.
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supporting information; experimental part
p. 6795 - 6797
(2010/12/19)
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- Practical, environment-benign and atom economic KOAc-catalysed deprotection of aryl TIPS ethers under mild fluoride-free conditions
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A KOAc-catalysed, fluoride-free protocol not only effects chemoselective deprotection of phenolic TIPS ethers without affecting acetal, ketal, carbamate, O-acetyl and aliphatic silyl ethers, but also improves its atom economy by recycling the silanol byproduct.
- Wang, Bing,Sun, Hui-Xia,Chen, Bo,Sun, Zhi-Hua
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supporting information; experimental part
p. 1112 - 1114
(2010/04/23)
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- In vitro characterization of the enzymes involved in TDP-D-forosamine biosynthesis in the spinosyn pathway of Saccharopolyspora spinosa
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Forosamine (4-dimethylamino)-2,3,4,6-tetradeoxy-β-d-threo- hexopyranose) is a highly deoxygenated sugar component of several important natural products, including the potent yet environmentally benign insecticide spinosyns. To study D-forosamine biosynthesis, the five genes (spnO, N, Q, R, and S) from the spinosyn gene cluster thought to be involved in the conversion of TDP-4-keto-6-deoxy-D-glucose to TDP-D-forosamine were cloned and heterologously expressed, and the corresponding proteins were purified and their activities examined in vitro. Previous work demonstrated that SpnQ functions as a pyridoxamine 5′-monophosphate (PMP)-dependent 3-dehydrase which, in the presence of the cellular reductase pairs ferredoxin/ferredoxin reductase or flavodoxin/flavodoxin reductase, catalyzes C-3 deoxygenation of TDP-4-keto-2,6-dideoxy-D-glucose. It was also established that SpnR functions as a transaminase which converts the SpnQ product, TDP-4-keto-2,3,6-trideoxy-D- glucose, to TDP-4-amino-2,3,4,6-tetradeoxy-D-glucose. The results presented here provide a full account of the characterization of SpnR and SpnQ and reveal that SpnO and SpnN functions as a 2,3-dehydrase and a 3-ketoreductase, respectively. These two enzymes act sequentially to catalyze C-2 deoxygenation of TDP-4-keto-6-deoxy-D-glucose to form the SpnQ substrate, TDP-4-keto-2,6-dideoxy- D-glucose. Evidence has also been obtained to show that SpnS functions as the 4-dimethyltransferase that converts the SpnR product to TDP-D-forosamine. Thus, the biochemical functions of the five enzymes involved in TDP-D-forosamine formation have now been fully elucidated. The steady-state kinetic parameters for the SpnQ-catalyzed reaction have been determined, and the substrate specificities of SpnQ and SpnR have been explored. The implications of this work for natural product glycodiversification and comparative mechanistic analysis of SpnQ and related NDP-sugar 3-dehydrases E1 and ColD are discussed.
- Hong, Lin,Zhao, Zongbao,Melancon III, Charles E.,Zhang, Hua,Liu, Hung-Wen
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p. 4954 - 4967
(2008/09/21)
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- Cathodic reduction of hydroxycarbonyl compound trichloroacetyl esters
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New coumarins and new 2-(2′,2′-dichlorovinyl) phenols have been prepared by cathodic reduction under potentiostatic conditions of trichloroacetyl esters of o-hydroxyketones and o-hydroxyaldehydes in aprotic media. Electroreductions of trichloroacetyl esters of α-hydroxy-1,4- naphthoquinone, 3-hydroxy-2-methyl-4-pyrone, methyl salicylate and benzoin have also been investigated.
- Dolly,Batanero,Barba
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p. 9161 - 9165
(2007/10/03)
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- Process for the preparation of maltol from plants belonging to the genus Abies
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A process has been developed for production of a food flavoring compound maltol which comprises (a) extracting the dried and pulverized leaves of the plants belonging to the genus Abies with an alcohol at 20-40° C. and concentrating the solvent to obtain an alcoholic extract, (b) adsorbing the alcoholic extract with an adsorbent and drying the adsorbed material at a temperature ranging between 20-50° C., (d) partitioning of the adsorbed material between selected solvents consisting of aliphatic hydrocarbon and chlorinated solvent successively, (d) concentrating the chlorinated solvent to a residue and crystallizing it from a suitable organic solvent or mixtures of such solvents to get pure maltol.
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- Evaluation of acute toxicity and genotoxicity of liquid products from pyrolysis of Eucalyptus grandis wood
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Slow pyrolysis of Eucalyptus grandis wood was performed in an oven laboratory, and smoke was trapped and condensed to yield liquid products. Polycyclic aromatic hydrocarbons (PAHs) and phenolic fractions were isolated from the former liquid products using adsorption column chromatography (ACC) and identified by GC/MS. Concentrations of PAH and phenolic fractions in total pyrolysis liquids were respectively 48.9 μg/g and 8.59% (w/w). Acute toxicity of total samples of pyrolysis liquids and the phenolic fraction was evaluated by means of two bioassays, namely, 24-h immobilization bioassay with Daphnia magna and Microtox(TM) bioassays, the latter employing the luminescent bacteria Photobacterium phosphoreum. Total pyrolysis liquids and the PAH fraction were evaluated for genotoxicity by the Microtox(TM) bioassay conducted using rehydrated freeze-dried dark mutant of the luminescent bacteria Vibrio fisheri strain M169. Total pyrolysis liquids and the phenolic fraction, respectively, in concentrations of 170 and 68 mg/L were able to immobilize 50% (EC50) of the D. magna population following 24-h exposure. Concentrations of 19 and 6 mg/L, respectively, for total pyrolysis liquids and phenolic fraction were the effective concentrations that resulted in a 50% (EC50) reduction in light produced by bacteria in the Microtox(TM) bioassay. Accordingly, the Microtox(TM) bioassay was more sensitive to toxic effects of both kind of samples than the D. magna bioassay, particularly for the phenolic fraction. Regarding to the genotoxicity evaluation, the results achieved by Microtox(TM) bioassay showed that total pyrolysis liquids had no genotoxic effects with and without exogenous metabolic activation using rat liver homogenate (S9). However, the PAH fraction showed toxic effects with rat liver activation and had a dose-response number (DRN) equal to 1.6, being in this way suspected genotoxic. The lowest detected concentration (LDC) of the PAH fraction able to cause genotoxic effects was 375 μg/L.
- Pimenta,Bayona,Garcia,Solanas
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p. 169 - 175
(2007/10/03)
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- Polymer pyrolysis and oxidation studies in a continuous feed and flow reactor: Cellulose and polystyrene
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A dual-zone, continuous feed tubular reactor is developed to assess the potential for formation of products from incomplete combustion in thermal oxidation of common polymers. Solid polymer (cellulose or polystyrene) is fed continuously into a volatilization oven where it fragments and vaporizes. The gas-phase polymer fragments flow directly into a second, main flow reactor to undergo further reaction. Temperatures in the main flow reactor are varied independently to observe conditions needed to convert the initial polymer fragments to CO2 and H2O. Combustion products are monitored at main reactor temperatures from 400 to 850 °C and at 2.0-s total residence time with four on-line GC/FIDs; polymer reaction products and intermediates are further identified by GC/MS analysis. Analysis of polymer decomposition fragments at 400 °C encompasses complex oxygenated and aromatic hydrocarbon species, which range from high-molecular-weight intermediates of ca. 300 amu, through intermediate mass ranges down to C1 and C2 hydrocarbons, CO, and CO2. Approximately 41 of these species are positively identified for cellulose and 52 for polystyrene. Products from thermal oxidation of cellulose and polystyrene are shown to achieve complete combustion to CO2 and H2O at a main reactor temperature of 850 °C under fuel-lean equivalence ratio and 2.0-s reaction time. A dual-zone, continuous feed tubular reactor is developed to assess the potential for formation of products from incomplete combustion in thermal oxidation of common polymers. Solid polymer (cellulose or polystyrene) is fed continuously into a volatilization oven where it fragments and vaporizes. The gas-phase polymer fragments flow directly into a second, main flow reactor to undergo further reaction. Temperatures in the main flow reactor are varied independently to observe conditions needed to convert the initial polymer fragments to CO2 and H2O. Combustion products are monitored at main reactor temperatures from 400 to 850°C and at 2.0-s total residence time with four on-line GC/FIDs; polymer reaction products and intermediates are further identified by GC/MS analysis. Analysis of polymer decomposition fragments at 400°C encompasses complex oxygenated and aromatic hydrocarbon species, which range from high-molecular-weight intermediates of ca. 300 amu, through intermediate mass ranges down to C1 and C2 hydrocarbons, CO, and CO2. Approximately 41 of these species are positively identified for cellulose and 52 for polystyrene. Products from thermal oxidation of cellulose and polystyrene are shown to achieve complete combustion to CO2 and H2O at a main reactor temperature of 850°C under fuel-lean equivalence ratio and 2.0-s reaction time.
- Park, Byung-Ik,Bozzelli, Joseph W.,Booty, Michael R.,Bernhard, Mary J.,Mesuere, Karel,Pettigrew, Charles A.,Shi, Ji-Chun,Simonich, Staci L.
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p. 2584 - 2592
(2007/10/03)
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- Effect of pressure on processes modelling the Maillard reaction
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The Maillard reaction between tryptophan and glucose or xylose was studied as a function of pressure. Using model reactions, volumes of activation for the formation of the intermediate imine and the Amadori rearrangement and for the decomposition of the aminoketose were measured as -14, 8 and 17 cm3mol-1, respectively. Pressure therefore accelerates the initial reactions but retards the formation of the final heterocyclic products and melanoidins. Oxygen was found to accelerate the latter reaction.
- Isaacs, Neil S.,Coulson, Mark
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p. 639 - 644
(2007/10/03)
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- A γ-PYRONYL-TRITERPENOID SAPONIN FROM PISUM SATIVUM
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A new triterpenoid saponin was isolated from Pisum sativum and characterized as 3-O-2)-β-D-galactopyranosyl(12)-β-D-glucuronopyranosyl(1)>-22-O-)>-3β,22β,24-trihydroxyolean-12-ene.The name chromosaponin I is proposed.Chromosaponin I yielded soyasaponin I, known as phytochrome inhibitor, during extraction, but the latter was not found in the free form in this plant. Key Word Index - Pisum sativum; Leguminosae; pea: phytochrome inhibitor; triterpenoid saponin; soyasaponin I derivative; chromosaponin I.
- Tsurumi, Seiji,Takagi, Toshihiro,Hashimoto, Tohru
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p. 2435 - 2438
(2007/10/02)
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- Process for the manufacture of γ-pyrones
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A process for the manufacture of 3-hydroxy-2-alkyl-4-pyrones of formula I is provided. STR1 The process comprises cyclizing a compound of formula II, STR2 in acidic medium and hydrolyzing the ester formed thereby to produce compound I. R1 represents methyl or ethyl; R2 represents lower alkanoyl or optionally substituted benzoyl; R3 represents --OH or --NR4 R5 ; and, R4 and R5 may be alike or different and represent lower alkyl. The pyrones of formula I wherein R1 represents methyl or ethyl are known flavorants and odorants.
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- Chemische und Chemotaxonimische Untersuchungen der Pterophyten. LXII. Chemische Untersuchungen der Inhaltsstoffe von Arachniodes maximowiczii OHWI
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Two new ent-rosane norditerpenes, ar-maximic acid (I) and ar-maximol (II), were isolated from the fronds of Arachniodes maximowiczii OHWI, and were shown to have the structures of 2-hydroxy-19-nor-ent-rosa-1,3,5(10),15(16)-tetraene 18-oic acid (I) and 2,18-dihydroxy-19-nor-ent-rosa-1,3,5(10),15(16)-tetraene (II) by chemical, spectroscopic and X-ray crystallographic methods.In addition, six glycosides of acyclic terpenes were isolated, and their structures were elucidated as 3(S)-linalool O-β-D-glucopyranoside (III), 3(S)-linalool O-β-D-(6'-O-β-L-fucopyranosyl)glucopyranoside (IV), 13-hydroxygeranyllinalool 13-O-β-D-(6'-O-β-L-fucopyranosyl)glucopyranoside (V), 13-hydroxygeranyllinalool 3,13-O-β-D-diglucopyranoside (VI), 13-methoxygeranyllinalool O-β-D-glucopyranoside (VII) and 15-methoxy-3,7,11,15-tetramethylhexadeca-1,6(E),10(E),13(E)-tetraene O-β-D-glucopyranoside (VIII), mainly by spectroscopic methods.Compounds VII and VIII, obtained as an inseparable mixture may be artefacts.Maltol and maltol β-D-glucoside were also isolated.Keywords - Arachniodes maximowiczii; ent-rosane-type norditerpene; acyclic monoterpene glycoside; acyclic diterpene glycoside; Aspidiaceae; fern; chemotaxonomy; X-ray analysis; 13C-NMR
- Tanaka, Nobutoshi,Sakai, Hideko,Murakami, Takao,Saiki, Yasuhisa,Chen, Chiu-Ming,Iitaka, Yoichi
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p. 1015 - 1022
(2007/10/02)
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- Process for the production of isosolanone and solanone, intermediates useful in said process and organoleptic uses of said intermediates
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Described is a novel genus of compounds defined according to the structure: STR1 wherein Z represents hydrogen, MgX and the moiety having the structure: STR2 and X represents chlor, bromo, or iodo; as well as 5-isopropyl-8-methyl-5,8-nonadien-2-one; uses of same as intermediates in a process for producing isosolanone and solanone; and organoleptic uses of 5-isopropyl-8-methyl-5,8-nonadien-2-one and 2,6-dimethyl-5-methylene-1-hepten-4-ol. The novel process of our invention involved the steps of: (i) formation of the compound having the structure: STR3 by means of reacting 3-methyl-2-methylenebutanal with the compound having the structure: STR4 (ii) acid hydrolysis of the resulting compound in order to form 2,6-dimethyl-5-methylene-1-heptene-4-ol; (iii) reaction of 2,6-dimethyl-5-methylene-1-hepten-4-ol with methyl aceto acetate in order to form 2,6-dimethyl-5-methylene-1-hepten-4-yl aceto acetate or, directly, 5-isopropyl-8-methyl-5,8-nonadiene-2-one; (iv) reacting 2,6-dimethyl-5-methylene-1-hepten-4-yl aceto acetate in the presence of an appropriate catalyst to form the 5-isopropyl-8-methyl-5,8-nonadiene-2-one; and (v) isomerizing the 5-isopropyl-8-methyl-5,8-nonadien-2-one in order to form a mixture of solanone and the isosolanone or 5-isopropyl-8-methyl-5,8-nonadiene-2-one.
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- Synthesis of 3-Amino-3,4-dideoxysugars
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Sequential treatment of methyl 3,4-O-isopropylidene-β-L-erythro-pentopyranosidulose (1) with aqueous sodium hydroxide and phenylhydrazine results in elimination of acetone and formation of 2S-methoxytetrahydropyran-3,4-dione 4-phenylhydrazone (7) as the main product.Similarly, methyl 6-deoxy-3,4-O-isopropylidene-α-L-lyxo-hexopyranosid-2-ulose (2) was converted into 2R-methoxy-6S-methyltetrahydropyran-3,4-dione 4-phenylhydrazone (8).The effect of base on the related uloside, methyl 6-deoxy-2,3-O-isopropylidene-α-L-lyxo-hexapyranoside-4-ulose (16),resulted in the formation of 3-hydroxy-2-methyl-4H-pyran-4-one (maltol) (17).Compounds (7) and (8) have been converted into, respectively, 3-amino-3,4-dideoxy-D-erythro-pentopyranose (22) and 3-amino-3,4,6-trideoxy-L-ribo-hexopyranose (25).
- Collins, Peter M.,Overend, W. George,Racz, Veronica M.
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p. 733 - 740
(2007/10/02)
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- Tetrahydropyran-5-one compounds
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A novel class of tetrahydropyran-5-one compounds are provided which are 2-alkoxy- or 2-acyloxy-3,4-dihalogeno-6-alkyl tetrahydropyran-5-ones expressed by the general formula STR1 where R1 is an alkyl group, R2 is an alkyl or an acyloxy group and X is a halogen atom. The compounds are synthesized by the reaction of a 2-furyl carbinol compound with a halogen in the presence of an alcohol or a carboxylic acid. The compounds are useful as an intermediate for the synthetic preparation of various useful compounds including maltol as a flavor.
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- Conversion of Secondary Furfuryl Alcohols and Isomaltol to Maltol and Related γ-Pyrones
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A one-pot synthesis of maltol and ethylmaltol is reported.Treatment of methylfurfuryl alcohol with 2 equiv of halogen affords good yields of 4-halo-6-hydroxy-2-methyl-2H-pyran-3(6H)-ones (8), which need not be isolated and can be converted to maltol by aqueous hydrolysis in the same vessel.A similar sequence employing ethylfurfuryl alcohol yields ethylmaltol.By a related series of reactions, isomaltol (9) can be converted to maltol.
- Weeks, Paul D.,Brennan, Thomas M.,Brannegan, Daniel P.,Kuhla, Donald E.,Elliot, Mark L.,et al.
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p. 1109 - 1113
(2007/10/02)
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- Preparation of gamma-pyrones from 3-substituted furans
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Gamma-pyrones are prepared by contacting a 3-halo-furfuryl alcohol or a 3-alkoxy-furfuryl alcohol with one equivalent of a halogen, peracid or peroxide oxidant and then heating until hydrolysis of the formed 4-substituted-dihydropyran intermediate is substantially complete. Maltol (2-methyl-3-hydroxy-4H-pyran-4-one) is prepared by this process from 2(1-hydroxyethyl)-3-alkoxy furans or 2(1-hydroxyethyl)-3-halo-furans. Gamma-pyrones are also prepared by contacting the corresponding 3-substituted-2,5-dialkoxy-furfuryl alcohols with acid until conversion to the gamma-pyrones is substantially complete.
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- Preparation of gamma-pyrones
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2-METHYL-3-HYDROXY-4H-pyran-4-one is prepared by contacting 1(2-furyl)-1-ethanol in aqueous solution with two equivalents of a halogen oxidant at room temperature and then heating until the hydrolysis of the formed 4-halo-dihydropyran intermediate is substantially complete. Other valuable related gamma-pyrones are prepared in analogous manner from appropriate alcohols.
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- Process for preparing 3-oxy-4H-pyran-4-one derivatives
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A process for preparing a 3-oxy-4H-pyran-4-one derivative which comprises the steps of: 1. epoxidizing a 3-oxo-3,6-dihydro-2H-pyran derivative with a peroxide to obtain a 4,5-epoxy-3-oxotetrahydropyran derivative, and 2. heating the 4,5-epoxy-3-oxotetrahydropyran derivative.
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