538-23-8

Basic information

• Product Name: TRIOCTANOIN
• Synonyms: 1,2,3-tris-(octanoyloxy)-propane;2,3-Bis(octanoyloxy)propyl octanoate;Caprylic triglyceride;Captex 8000;Glycerol trioctanoate;Glyceroltrioctanoate;Glyceryl tricaprylate-caprate;Maceight
• CAS NO: 538-23-8
• Molecular Formula: C₂₇H₅₀O₆
• Molecular Weight: 470.68
• EINECS: 208-686-5
• Mol File: 538-23-8.mol
• Article Data: 11

Chemical Properties

• Melting Point: 9-10 °C
• Boiling Point: 233 °C1 mm Hg(lit.)
• Flash Point: 225 °C
• Appearance: /
• Density: 0.956 g/mL at 20 °C(lit.)
• Vapor Pressure: 1.92E-10mmHg at 25°C
• Refractive Index: n20/D 1.448
• Storage Temp.: 2-8°C
• Solubility: Miscible with most organic solvents including ethanol (95%). Captex 8000 is insoluble in water.
• Water Solubility: 65mg/L at 20℃
• BRN: 1717202
• CAS DataBase Reference: TRIOCTANOIN(CAS DataBase Reference)
• NIST Chemistry Reference: TRIOCTANOIN(538-23-8)
• EPA Substance Registry System: TRIOCTANOIN(538-23-8)

Safety Data

• Safety Statements: 23-24/25
• RTECS: YJ7700000
• Hazardous Substances Data: 538-23-8(Hazardous Substances Data)

Usage

Description

1,2,3-Trioctanoyl glycerol is a triacylglycerol that contains octanoic acid at the sn-1, sn-2, and sn-3 positions. Dietary administration of 1,2,3-trioctanoyl glycerol (260 g/kg diet) increases hepatic and adipose tissue glucose-6-phosphate dehydrogenase (G6PDH), citrate cleavage enzyme (CCE), and malic enzyme activities in rats. It induces nuclear edema and cytolysis in tumor cells, but not normal hepatic cells, in a murine hepatic carcinoma model.

Chemical Properties

Different sources of media describe the Chemical Properties of 538-23-8 differently. You can refer to the following data:
1. Tricaprylin occurs as a clear, colorless to pale-yellow liquid. It forms crystals from acetone/ethanol (95%). Tricaprylin is odorless.
2. clear colorless to yellow viscous liquid

Uses

Different sources of media describe the Uses of 538-23-8 differently. You can refer to the following data:
1. glyceryl trioctanoate is an emollient with skin-softening abilities.
2. tricaprylin is a skin-conditioning agent.
3. Glytex(R) 273 is a low viscosity polyol ester suggested for use as a synthetic fiber lubricant. It offers a balance of moderate volatility and low varnishing behavior. For low to moderate denier polyester and nylon filament and staple yarn applications. Product Data Sheet

Definition

ChEBI: A triglyceride obtained by acylation of the three hydroxy groups of glycerol by octanoic acid. Used as an alternative energy source to glucose for patients with mild to moderate Alzheimer's disease.

Production Methods

Tricaprylin is a triglyceride manufactured by esterification of caprylic acid and glycerin.

General Description

Odorless viscous clear colorless to amber-brown liquid.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

TRIOCTANOIN is an ester. Esters react with acids to liberate heat along with alcohols and acids. Strong oxidizing acids may cause a vigorous reaction that is sufficiently exothermic to ignite the reaction products. Heat is also generated by the interaction of esters with caustic solutions. Flammable hydrogen is generated by mixing esters with alkali metals and hydrides. TRIOCTANOIN is incompatible with strong oxidizers. .

Fire Hazard

TRIOCTANOIN is combustible.

Flammability and Explosibility

Notclassified

Pharmaceutical Applications

Tricaprylin is used in pharmaceutical preparations as a neutral carrier, absorption promoter, and solubilizer for active drugs. It has been used as an oily phase to prepare water-in-oil-in-water multiple emulsions for incorporating water-soluble drugs such as cefadroxil, cephradine, 4-aminoantipyrine, and antipyrine, and also for obtaining stable microcapsules. Tricaprylin acts as a vehicle for topical creams and lotions, and cosmetic preparations. It is used as a penetration-enhancing lipid base with excellent emollient and skin-smoothing properties. Owing to its non-greasy components and low viscosity, it has very good spreadability. In spite of being skin-permeable, tricaprylin does not obstruct natural skin respiration, and hence it is used in baby oils, massage oils, and face masks. It is an excellent dispersant, and acts as a solubilizer, wetting agent and binder in color cosmetics. Being readily miscible with natural oils and surfactants, tricaprylin is used as the fat component in two-phase foam baths. It is used in sunscreen creams and oils because of its compatibility with organic and inorganic filter agents. It is also used as a fixative for perfumes/fragrances.

Biochem/physiol Actions

Glyceryl trioctanoate might serve as a skin softening agent. It possesses caprylic acid as the aliphatic chain.

Safety Profile

Poison by intraperitoneal route. Moderately toxic by intravenous route. Mildly toxic by ingestion. Experimental reproductive effects. When heated to decomposition it emits acrid smoke and irritating fumes. See also ESTERS.

Safety

Tricaprylin is used in pharmaceutical and cosmetic formulations. The Cosmetic Ingredient Review (CIR) Expert Panel found that dermal application of tricaprylin has not been associated with significant irritation in rabbit skin. However, as a penetration enhancer, tricaprylin may allow other chemicals to penetrate deeper into the skin, increasing their concentration so that they may reach the bloodstream. Ocular exposures of tricaprylin were found to be only mildly irritating to rabbit eyes. Little or no acute, subchronic, or chronic oral toxicity was observed in animal studies unless levels approached a significant percentage of caloric intake. Subcutaneous injections of tricaprylin in rats over a period of 5 weeks caused a granulomatous reaction. Tricaprylin has not been found to be teratogenic in rats, mice, or hamsters, but some reproductive effects have been seen in rabbits. Dose-related central nervous system toxicity in dogs has also been observed. LD50 (mouse, IP): >27.8 g/kg LD50 (mouse, IV): 3.7 g/kg LD50 (mouse, oral): 29.6 g/kg LD50 (mouse, SC): >27.8 g/kg LD50 (rat, IP): 0.05 g/kg LD50 (rat, IV): 4 g/kg LD50 (rat, oral): 33.3 g/kg

Carcinogenicity

In F344 rats given 10 mL/kg of tricaprylin by gavage daily for 2 years, there is significant increase in the incidence of squamous cell papillomas of the forestomach, compared to controls .

storage

Tricaprylin is classified as a stable compound. It has high stability against oxidation and is not heat sensitive. Even in hot climates cooling is not necessary. However, exposure to high temperatures near the flash point (246℃) should be avoided. Owing to its very low water content, it is not sensitive to hydrolytic and microbial splitting. Although polymerization of tricaprylin will not occur, it is reported to decompose into carbon monoxide and carbon dioxide. Tricaprylin should be stored in well-closed containers, protected from light, in a dry place at ambient temperature. High-density polyethylene, polypropylene, metal (aluminum), and glass are suitable for packaging. Some plastics, especially those containing plasticizers, can become brittle or expand in the presence of tricaprylin. Polystyrene and polyvinyl chloride are not suitable for its storage. Tricaprylin has a high tendency to migrate, and therefore care should be taken when selecting seal-closure elastomer material.

Incompatibilities

Tricaprylin is incompatible with strong oxidizing agents.

Regulatory Status

Included in the FDA Inactive Ingredients Database (epidural injections).

InChI:InChI=1/C27H50O6/c1-4-7-10-13-16-19-25(28)31-22-24(33-27(30)21-18-15-12-9-6-3)23-32-26(29)20-17-14-11-8-5-2/h24H,4-23H2,1-3H3

Synthetic route

Octanoic acid (124-07-2) + glycerol (56-81-5) → tricaprilin (538-23-8)

Conditions	Yield
With acetic acid at 275℃; for 0.5h;	99.2%
With tungsten(VI) oxide at 175℃; under 1 Torr; for 22h; Reagent/catalyst;	93%
at 100℃; Beim Erhitzen in Gegenwart von aus Naphthalin,Oelsaeure und konz.Schwefelsaeure in Petrolaether dargestelltem Twitchells Reagens;

glycerol (56-81-5) + n-octanoic acid chloride (111-64-8) → tricaprilin (538-23-8)

Conditions	Yield
With pyridine; tetrachloromethane

Octanoic acid (124-07-2) + glycerol (56-81-5) → tricaprilin (538-23-8) + monocaprylin (19670-49-6) + 1,3-dicaprylin (1429-66-9) + 1,2-dioctanoylglycerol (1069-87-0)

Conditions	Yield
With lipozyme at 25℃; under 3 Torr; for 8h; Enzyme kinetics; Product distribution; Further Variations:; Reaction partners; Temperatures; Esterification;	A 3.60 % Chromat. B 8.44 % Chromat. C 84.63 % Chromat. D 0.45 % Chromat.
With lipozyme at 25℃; under 3 Torr; for 8h; Esterification;	A 3.60 % Chromat. B 8.44 % Chromat. C 84.63 % Chromat. D 0.45 % Chromat.

glycerol (56-81-5) + n-octanoic acid chloride (111-64-8) → tricaprilin (538-23-8) + monoglyceride, diglyceride

Conditions	Yield
With potassium hydroxide; water at -10 - 0℃;

methyl octanate (111-11-5) + Methyl decanoate (110-42-9) + glycerol (56-81-5) → decanoic acid 2-decanoyloxy-3-octanoyloxypropyl ester + decanoic acid 2-octanoyloxy-1-octanoyloxymethylethyl ester + decanoic acid 2,3-bis-octanoyloxypropyl ester + decanoic acid 3-decanoyloxy-2-octanoyloxypropyl ester + tricaprilin (538-23-8) + capric acid triglyceride (621-71-6)

Conditions	Yield
potassium methanolate at 60 - 200℃; for 0.916667h; Industry scale; Under nitrogen;

...Expand

suberin → 9,10-epoxy-18-hydroxyoctadecanoic acid (3233-92-9) + tricaprilin (538-23-8) + octyl octylate (2306-88-9)

Conditions	Yield
With 2-hydroxy-N,N,N-trimethylethan-1-aminium hexanoate In water at 100℃; for 8h;

Octanoic acid (124-07-2) + glycerol (56-81-5) → tricaprilin (538-23-8) + 1,3-dicaprylin (1429-66-9) + 1,2-dioctanoylglycerol (1069-87-0)

Conditions	Yield
With sulphonated hydrothermal carbon at 115℃; for 24h; Catalytic behavior; chemoselective reaction;

Octanoic acid (124-07-2) + glycerol (56-81-5) → tricaprilin (538-23-8) + monocaprylin (19670-49-6) + 1,3-dicaprylin (1429-66-9)

Conditions	Yield
With sulfuric acid In water at 100℃; under 400 Torr; for 5h;

methanol (67-56-1) + tricaprilin (538-23-8) → methyl octanate (111-11-5)

Conditions	Yield
With hafnium(IV) trifluoromethanesulfonate; palladium 10% on activated carbon; hydrogen In neat (no solvent) at 200℃; for 2h;	100%
With C9H18BiNO3S2 for 19h; Reagent/catalyst; Reflux;	75%
sulafted zirconia at 120℃; under 5168.35 Torr; Product distribution; Further Variations:; Catalysts;
With 5 wtpercent Mg-HT/Al2O3 In butan-1-ol at 60℃; Catalytic behavior; Reagent/catalyst;
With C10H21InN2O2S2 for 19h; Reagent/catalyst; Reflux;

tricaprilin (538-23-8) → methyl octanate (111-11-5)

Conditions	Yield
With C16H25N3O2S In methanol at 23℃; for 24h;	99%

methanol (67-56-1) + tricaprilin (538-23-8) → methyl octanate (111-11-5) + glycerol (56-81-5)

Conditions	Yield
With C11H12N2Pol In tetrahydrofuran at 20℃; for 1h; Time; Concentration;	A 98% B n/a
With Amberlyst 15 hydrogen at 60℃;

1,2,3,4-tetrahydroisoquinoline (635-46-1) + tricaprilin (538-23-8) → 1-octyl-1,2,3,4-tetrahydroquinoline

Conditions	Yield
With tris(2,4-pentanedionato)ruthenium(III); hydrogen; bis(trifluoromethanesulfonyl)amide; [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] In tetrahydrofuran at 130℃; under 45004.5 Torr; for 18h; Autoclave;	96%

1-indoline (496-15-1) + tricaprilin (538-23-8) → N-octyl-indoline

Conditions	Yield
With tris(2,4-pentanedionato)ruthenium(III); hydrogen; bis(trifluoromethanesulfonyl)amide; [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] In tetrahydrofuran at 130℃; under 45004.5 Torr; for 18h; Autoclave;	92%

tricaprilin (538-23-8) + 2-aminofluorene (153-78-6) → N-octyl-9H-fluoren-2-amine

Conditions	Yield
With tris(2,4-pentanedionato)ruthenium(III); hydrogen; bis(trifluoromethanesulfonyl)amide; [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] In tetrahydrofuran at 130℃; under 45004.5 Torr; for 18h; Autoclave;	90%

tricaprilin (538-23-8) + benzyl-methyl-amine (103-67-3) → N-methyl,N-(n-octyl) benzylamine (63991-66-2)

Conditions	Yield
With tris(2,4-pentanedionato)ruthenium(III); hydrogen; bis(trifluoromethanesulfonyl)amide; [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] In tetrahydrofuran at 130℃; under 45004.5 Torr; for 18h; Autoclave;	90%

tricaprilin (538-23-8) + benzo[1,3]dioxolo-5-ylamine (14268-66-7) → N-octylbenzo[d][1,3]dioxol-5-amine (1039864-69-1)

Conditions	Yield
With tris(2,4-pentanedionato)ruthenium(III); hydrogen; bis(trifluoromethanesulfonyl)amide; [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] In tetrahydrofuran at 130℃; under 45004.5 Torr; for 18h; Autoclave;	88%

tricaprilin (538-23-8) + N-methylaniline (100-61-8) → (N-methyl-N-octyl)aniline (13063-61-1)

Conditions	Yield
With tris(2,4-pentanedionato)ruthenium(III); hydrogen; bis(trifluoromethanesulfonyl)amide; [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] In tetrahydrofuran at 130℃; under 45004.5 Torr; for 18h; Autoclave;	87%

tricaprilin (538-23-8) → caprylnitrile (124-12-9)

Conditions	Yield
With ammonia at 220℃; for 40h; Autoclave;	86%

tricaprilin (538-23-8) + 4-chloro-aniline (106-47-8) → N-(4-chlorophenyl)octylamine (92328-83-1)

Conditions	Yield
With tris(2,4-pentanedionato)ruthenium(III); hydrogen; bis(trifluoromethanesulfonyl)amide; [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] In tetrahydrofuran at 130℃; under 45004.5 Torr; for 18h; Autoclave;	85%

tricaprilin (538-23-8) + 4-amino-phenol (123-30-8) → 4-hydroxy-N-octyl-aniline (22792-02-5)

Conditions	Yield
With tris(2,4-pentanedionato)ruthenium(III); hydrogen; bis(trifluoromethanesulfonyl)amide; [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] In tetrahydrofuran at 130℃; under 45004.5 Torr; for 18h; Autoclave;	85%

tricaprilin (538-23-8) + dibenzylamine (103-49-1) → N,N-Bis(phenylmethyl)octanamine (33735-29-4)

Conditions	Yield
With tris(2,4-pentanedionato)ruthenium(III); hydrogen; bis(trifluoromethanesulfonyl)amide; [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] In tetrahydrofuran at 130℃; under 45004.5 Torr; for 18h; Autoclave;	83%

tricaprilin (538-23-8) + 2-Anilinoethanol (122-98-5) → 2-(octyl(phenyl)amino)ethan-1-ol

Conditions	Yield
With tris(2,4-pentanedionato)ruthenium(III); hydrogen; bis(trifluoromethanesulfonyl)amide; [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] In tetrahydrofuran at 150℃; under 45004.5 Torr; for 18h; Autoclave;	83%

astaxanthin esters + tricaprilin (538-23-8) → astaxanthin octanoic acid monoester + 3,3'-dihydroxy-β,β-carotene-4,4'-dione (7542-45-2) + di-O-octanoyl-all-trans-astaxanthin

Conditions	Yield
lipase PL (from Alcaligenes) In water at 45℃; for 72h; Product distribution / selectivity; Enzymatic reaction;	A 4% B 79.3% C 1%
immobilized lipase In water at 45℃; for 96h; Product distribution / selectivity; Enzymatic reaction;	A 12.2% B 64% C 1%
immobilized lipase of Phenyl Toyopearl In water at 45℃; for 96h; Product distribution / selectivity; Enzymatic reaction;	A 14.1% B 61.6% C 2.8%

tricaprilin (538-23-8) + N-methyl(p-chloroaniline) (932-96-7) → 4-chloro-N-methyl-N-octylaniline

Conditions	Yield
With tris(2,4-pentanedionato)ruthenium(III); hydrogen; bis(trifluoromethanesulfonyl)amide; [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] In tetrahydrofuran at 130℃; under 45004.5 Torr; for 18h; Autoclave;	79%

tricaprilin (538-23-8) + 4-phenoxyanilin (139-59-3) → N-octyl-4-phenoxyaniline

Conditions	Yield
With tris(2,4-pentanedionato)ruthenium(III); hydrogen; bis(trifluoromethanesulfonyl)amide; [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] In tetrahydrofuran at 130℃; under 45004.5 Torr; for 18h; Autoclave;	78%

tricaprilin (538-23-8) + 4-methylsulfanylaniline (104-96-1) → 4-(methylthio)-N-octylaniline

Conditions	Yield
With tris(2,4-pentanedionato)ruthenium(III); hydrogen; bis(trifluoromethanesulfonyl)amide; [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] In tetrahydrofuran at 130℃; under 45004.5 Torr; for 18h; Autoclave;	76%

tricaprilin (538-23-8) + 3-methoxy-N-methylaniline (14318-66-2) → 3-methoxy-N-methyl-N-octylaniline

Conditions	Yield
With tris(2,4-pentanedionato)ruthenium(III); hydrogen; bis(trifluoromethanesulfonyl)amide; [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] In tetrahydrofuran at 130℃; under 45004.5 Torr; for 18h; Autoclave;	74%

tricaprilin (538-23-8) + astaxanthin oleic acid diester → astaxanthin octanoic acid monoester + 3,3'-dihydroxy-β,β-carotene-4,4'-dione (7542-45-2) + di-O-octanoyl-all-trans-astaxanthin

Conditions	Yield
lipase OF (from Candida) In water at 45℃; for 240h; Product distribution / selectivity; Enzymatic reaction;	A 27.2% B 72.8% C 1%

2-Fluoroaniline (348-54-9) + tricaprilin (538-23-8) → (2-fluorophenyl)octylamine (936747-22-7)

Conditions	Yield
With tris(2,4-pentanedionato)ruthenium(III); hydrogen; bis(trifluoromethanesulfonyl)amide; [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] In tetrahydrofuran at 150℃; under 45004.5 Torr; for 18h; Autoclave;	69%

tricaprilin (538-23-8) + 3-aminobenzenemethanol (1877-77-6) → (3-(octylamino)phenyl)methanol

Conditions	Yield
With tris(2,4-pentanedionato)ruthenium(III); hydrogen; bis(trifluoromethanesulfonyl)amide; [2-((diphenylphospino)methyl)-2-methyl-1,3-propanediyl]bis[diphenylphosphine] In tetrahydrofuran at 130℃; under 45004.5 Torr; for 18h; Autoclave;	65%

tricaprilin (538-23-8) → octanol (111-87-5)

Conditions	Yield
With 5 wt% Re/TiO2; hydrogen In neat (no solvent) at 230℃; under 37503.8 Torr; for 24h; Autoclave;	62%

tricaprilin (538-23-8) + 3,3'-dihydroxy-β,β-carotene-4,4'-dione (7542-45-2) → astaxanthin octanoic acid monoester + di-O-octanoyl-all-trans-astaxanthin

Conditions	Yield
immobilized lipase In hexane; water at 45℃; for 72h; Product distribution / selectivity; Enzymatic reaction;	A 23.9% B 2.3%
immobilized lipase In water at 45℃; for 72h; Product distribution / selectivity; Enzymatic reaction;	A 21.9% B 2.6%
HPA25 resin-immobilized lipase In water at 45℃; for 72h; Product distribution / selectivity; Enzymatic reaction;	A 19.2% B 1%

astaxanthin esters + tricaprilin (538-23-8) → astaxanthin octanoic acid monoester + 3,3'-dihydroxy-β,β-carotene-4,4'-dione (7542-45-2)

Conditions	Yield
immobilized lipase In hexane; water at 45℃; for 72h; Product distribution / selectivity; Enzymatic reaction;	A 1% B 15.2%

tricaprilin (538-23-8) + capric acid triglyceride (621-71-6) + 3,3'-dihydroxy-β,β-carotene-4,4'-dione (7542-45-2) → astaxanthin octanoic acid monoester + di-O-octanoyl-all-trans-astaxanthin + astaxanthin decanoic acid monoester + astaxanthin decanoic acid diester

Conditions	Yield
immobilized lipase In hexane; water at 45℃; for 72h; Product distribution / selectivity; Enzymatic reaction;	A 9.5% B 1% C 9.1% D 1%
immobilized lipase In water at 45℃; for 72h; Product distribution / selectivity; Enzymatic reaction;	A 7.2% B 1% C 6.1% D 1%
lipase OF (from Candida) In water at 45℃; for 72h; Product distribution / selectivity; Enzymatic reaction;	A 3.9% B 1% C 3% D 1%

astaxanthin esters + tricaprilin (538-23-8) → astaxanthin octanoic acid monoester + di-O-octanoyl-all-trans-astaxanthin

Conditions	Yield
HP1MG resin-immobilized lipase In water at 45℃; for 72h; Product distribution / selectivity; Enzymatic reaction;	A 5.4% B 1%

tricaprilin (538-23-8) + 3,3'-dihydroxy-β,β-carotene-4,4'-dione (7542-45-2) → astaxanthin octanoic acid monoester

Conditions	Yield
immobilized lipase with HP 20 In water at 45℃; for 72h; Product distribution / selectivity; Enzymatic reaction;	3.9%

Upstream product

• 56-81-5 glycerol 
• 111-64-8 n-octanoic acid chloride 
• 111-11-5 methyl octanate 
• 110-42-9 Methyl decanoate 
• 124-07-2 Octanoic acid 

Downstream Products

• 56-81-5 glycerol 
• 111-86-4 n-Octylamine 
• 111-65-9 octane 
• 111-87-5 octanol 
• 142-82-5 n-heptane 
• 124-07-2 Octanoic acid 
• 624-13-5 propyl octanoate 
• 2306-88-9 octyl octylate 
• 149-91-7 3,4,5-trihydroxybenzoic acid 
• 111-11-5 methyl octanate 
• 1120-48-5 n-dioctylamine 
• 124-12-9 caprylnitrile 
• 629-01-6 n-octanamide 
• 1135-24-6 3-(4-hydroxy-3-methoxyphenyl)acrylic acid 

Relevant articles and documents

Development of a lipase-mediated epoxidation process for monoterpenes in choline chloride-based deep eutectic solvents

Chemical syntheses in contemporary process industries today are predominantly conducted using organic solvents, which are potentially hazardous to humans and the environment alike. Green chemistry was developed as a means to overcome this hazard and it also holds enormous potential for designing clean, safe and sustainable processes. The present work incorporates the concepts of green chemistry in its design of a lipase-mediated epoxidation process for monoterpenes; the process uses alternative reaction media, namely deep eutectic solvents (DESs), which have not been reported for such an application before. Choline chloride (ChCl), in combination with a variety of hydrogen bond donors (HBD) at certain molar ratios, was screened and tested for this purpose. The process was optimized through the design of experiments (DoE) using the Taguchi method for four controllable parameters (temperature, enzyme amount, peroxide amount and type of substrate) and one uncontrollable parameter (DES reaction media) in a crossed-array design. Two distinct DESs, namely glycerol:choline chloride (GlCh) and sorbitol:choline chloride (SoCh), were found to be the best systems and they resulted in a complete conversion of the substrates within 8 h. Impurities (esters) were found to form in both the DESs, which was a concern; as such, we developed a novel minimal DES system that incorporated a co-substrate into the DES so that this issue could be overcome. The minimal DES consisted of urea·H2O2 (U·H2O2) and ChCl and exhibited better results than both the GlCh and SoCh systems; complete conversions were achieved within 2 h for 3-carene and within 3 h for both limonene and α-pinene. Product isolation with a simple water/ethyl acetate based procedure gave isolated yields of 87.2 ± 2.4%, 77.0 ± 5.0% and 84.6 ± 3.7% for 3-carene, limonene and α-pinene respectively.

Biobased catalyst in biorefinery processes: Sulphonated hydrothermal carbon for glycerol esterification

Sulphonated hydrothermal carbon (SHTC), obtained from d-glucose by mild hydrothermal carbonisation and subsequent sulphonation with sulphuric acid, is able to catalyse the esterification of glycerol with different carboxylic acids, namely, acetic, butyric and caprylic acids. Product selectivity can be tuned by simply controlling the reaction conditions. On the one hand, SHTC provides one of the best selectivity towards monoacetins described up to now without the need for an excess of glycerol. On the other hand, excellent selectivity towards triacylglycerides (TAG) can be obtained, beyond those described with other solid catalysts, including well-known sulphonic resins. Recovery of the catalyst showed partial deactivation of the solid. The formation of sulphonate esters on the surface, confirmed by solid state NMR, was the cause of this behaviour. Acid treatment of the used catalyst, with subsequent hydrolysis of the surface sulphonate esters, allows SHTC to recover its activity. The higher selectivity towards mono- and triesters and its renewable origin makes SHTC an attractive catalyst in biorefinery processes.