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1.
The syntheses of geranyl acetate and citronellyl acetate by alcoholysis reaction catalyzed by immobilized lipase from Mucor miehei was studied for the first time in a solvent-free system. Reactions were carried out at a terpene alcohol/acyl donor molar
ratio of 1:5 with Lipozyme at 10% of the total weight of the reactants in a solvent-free system. Incubations were carried
out at 55 to 60°C for ethyl and butyl acetates as acyl donors, whereas for methyl acetate the incubation temperature was 40
to 45°C. Excess concentration of acyl donor increases the percentage of geranyl acetate and citronellyl acetate, while excess
of terpene alcohol concentration decreases the same. Yields from 75 to 77% molar conversion (90 to 98% conversion, w/w) were
obtained after 8 to 28 h of reaction time. 相似文献
2.
Lisa N. Yee Casimir C. Akoh Robert S. Phillips 《Journal of the American Oil Chemists' Society》1997,74(3):255-260
Pseudomonas sp. lipase PS was immobilized by adsorption and tested for its ability to catalyze the synthesis of citronellyl butyrate
and geranyl caproate by transesterification in n-hexane. The reaction parameters investigated were: enzyme load, effect of substrate concentration, added water, temperature,
time course, organic solvent, pH memory, and enzyme reuse. Yields as high as 96 and 99% were obtained for citronellyl butyrate
and geranyl caproate, respectively, with 300 units (approx. 15% w/w of reactants) of lipase PS. Increasing amounts of terpene
alcohol inhibited lipase activity, while excess acyl donor (triacylglycerol) concentration enhanced ester production. Optimal
yields were obtained at temperatures from 30–50°C after 24-h incubation time. Yields of 90 and 99% were obtained for citronellyl
and geranyl esters, respectively, with 2% added water. Solvents with log P values ≥ 2.5 showed the highest conversion yields. pH 7 and 6–8 seemed to be ideal for citronellyl butyrate and geraniol
caproate, respectively. The lipase remained active after reusing 12 times. 相似文献
3.
Chen Jyh-Ping Lin Wei-Shin Chang Min-Far 《Journal of the American Oil Chemists' Society》2002,79(3):309-314
Candida cylindracea lipase was entrapped in organic-inorganic hybrid sol-gel polymers made from tetramethoxysilane (TMOS) and alkyltrimethoxysilanes.
By forming the gels within the pores of a nonwoven polyester fabric, a novel immobilized biocatalyst in sheet configuration
based on sol-gel en-trapment of the enzyme was obtained. Lipases immobilized in sol-gel matrices efficiently catalyzed the
direct esterification reaction of geraniol and acetic acid in anhydrous hexane to produce geranyl acetate. The optimal formulation
of the sol-gel solution for enzyme immobilization was at a 20∶1 molar ratio of water to total silane; a 4∶1 molar ratio of
propyltrimethoxysilane to TMOS; hydrolysis time at 30 min; and enzyme loading of 200 mg lipase/g gel. Under these conditions,
protein immobilization efficiency was 91%, and the specific activity of the immobilized enzyme was 2.6 times that of the free
enzyme. Excellent thermal stability was found for the immobilized enzyme in dry form or in hexane solution in the presence
of acetic acid, in which case severe inactivation of free enzyme was observed. The immobilized enzyme retained its activity
after heating at 70°C for 2 h, whereas the free enzyme lost 80% of its activity. 相似文献
4.
Shamsher S. Kanwar Satyendra Gehlot Madan Lal Verma Reena Gupta Yogesh Kumar Ghansham S. Chauhan 《应用聚合物科学杂志》2008,110(5):2681-2692
Microbial lipases (E.C. 3.1.1.3) are the preferred biocatalysts for the synthesis of various fragrance compounds, such as linalool acetate, citronellal acetate, and geranyl acetate, in organic solvents over chemical synthesis. In this study, a purified alkaline extracellular lipase of Pseudomonas aeruginosa MTCC‐4713 was efficiently immobilized onto a synthetic poly(AAc‐co‐HPMA‐cl‐EGDMA) hydrogel by surface adsorption, and the bound lipase was evaluated for its hydrolytic potential toward various p‐nitrophenyl acyl esters, which differed in their C‐chain length. Among four series of hydrogels prepared by the variation of the concentrations of monomer and crosslinker, two hydrogels, namely, I5d and I20d, that exhibited relatively higher protein (lipase activity) bindings were selected to perform hydrolytic and synthetic (geranyl butyrate) reactions in aqueous and organic solvents. The hydrogel‐bound lipase was highly hydrolytic toward p‐nitrophenyl ester (C: 16; p‐nitrophenyl palmitate). The hydrogel‐immobilized lipase was quite stable and retained approximately 57.6% of its original hydrolytic activity after the fifth cycle of reuse under optimized conditions (pH 8.5, 65°C). The hydrogel‐immobilized lipase when used to perform the esterification of geraniol/butyric acid (400 : 100 mM) in n‐heptane resulted in 98.8 mM geranyl butyrate at 65°C under shaking (120 rpm) after 15 h of reaction time. The addition of a molecular sieve (3 Å × 1.5 mm) to the reaction system at a concentration of 100 mg per reaction volume (1 mL) resulted in the complete conversion of the reactants into geranyl butyrate. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
5.
Shih‐Yow Huang Hsiao‐Li Chang 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1999,74(2):183-187
Surfactant‐coated lipase (SCL) was prepared by coating the surface of Candida cylindracea lipase with the non‐ionic surfactant, Span 85. SCL catalyzed the esterification of geraniol and acetic acid. The ester product, geranyl acetate, is an important component of flavor and fragrance compounds. The SCL prepared in this work had low solubility in organic solvent, unlike those prepared by other investigators. A kinetic study of the mechanism of the lipolytic esterification and the reaction rate for facilitating the scale‐up of the reactors indicated a ping‐pong bi bi model with competitive substrate inhibition by acetic acid and dead‐end inhibition by acetic acid. Experimental data agreed with the proposed model. Kinetic parameters, Ki , Km (AA) , Km(GOH) and Vmax , were determined which visualized the reaction mechanism of the SCL esterification. © 1999 Society of Chemical Industry 相似文献
6.
B. K. De T. Chatterjee D. K. Bhattacharyya 《Journal of the American Oil Chemists' Society》1999,76(12):1501-1504
Synthesis of geranyl and citronellyl esters of mixed fatty acids has been investigated by alcoholysis of coconut oil (CNO)
using Rhizomucor miehei lipase. CNO fatty acid esters of geraniol and citronellol have unique mild flavors that can be used in food materials. Both
geraniolysis and citronellolysis of CNO produce flavor esters in good yield. Depending on substrate concentration the molar
yield is more than 50%. The optimized reaction conditions were: pressure, atmospheric; temperature, 50°C; incubation period,
5 h; and Lipozyme, 10% (w/w). 相似文献
7.
We prepared a composite gel fiber by the gel formation of cellulose acetate and zirconium tetra-n-butoxide. Gel fiber is stable in common solvents, phosphate solution, and electrolyte solution. Invertase was entrap-immobilized on the gel fiber. The immobilization was easily performed under the mild conditions. The apparent Michaelis constant (Km) and maximum reaction velocity (Vmax) were estimated from Eadie–Hofstee plot for immobilized invertase. The Km of immobilized invertase was larger than that of native invertase, while the opposite tendency was observed for the Vmax. The activity for the immobilized invertase became higher with increasing fiber diameter. It indicates that the hydrolysis of sucrose occurs in the neighborhood of the fiber surface. The thermal stability of the immobilized invertase was higher than those of its native counterpart. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2084–2088, 2001 相似文献
8.
The mandibular glands of the stem-nesting Indian beePithitis smaragdula contain a mixture of salicylaldehyde, citronellyl acetate, geranyl acetate, pentadecane, heptadecane, ethyl tetradecanoate, and ethyl hexadecanoate. Salicylaldehyde is reported for the first time from a hymenopterous source. The secretion, emitted when the bee is disturbed, is rubbed with the legs over the bee's body and the disturbing object. The reactivity of some of the components in combination with the bee's behavior make the glandular exudate an effective defensive secretion. 相似文献
9.
Geranyl acetate is an important flavor and fragrance compound. Two immobilizedCandida antarctica lipases, SP382 and SP435, were investigated for their use in the synthesis of geranyl acetate by direct esterification. Yields
between 95 and 99% molar conversion were obtained with 2 and 15% (w/w reactants) of SP435 and SP382 lipases, respectively.
Optimum yields were obtained at 0.1M acetic acid and 0.12M geraniol after 16-h incubation. No inhibitory effect was observed
at increasing concentrations of geraniol. Addition of 60% (w/w reactants) water led to 50 and 60% reduction in the esterification
activity of SP382 and SP435 lipases, respectively. The best yields were obtained at added water contents between 0–5% (w/w
reactants). Solvents with a logP value of 0.85 or more gave reaction yields of more than 80% molar conversion. Higher logP values did not necessarily lead to higher conversion yields. The immobilized lipase SP382 was still active after reusing
ten times in the direct esterification reaction. 相似文献
10.
Pseudomonas sp. lipase (PS) was immobilized by adsorption technique onto glass beads and tested for its ability to synthesize geranyl
acetate by transesterification with acetic anhydride as the acyl donor. Reactions were carried out inn-hexane containing 0.1 M geraniol, 0.1 M acetic anhydride, and 200 units of lipase PS. Enzyme load, effect of substrate concentration,
added water, temperature, time course, organic solvent, pH memory, and enzyme reuse were studied. Yields of up to 96% were
obtained with 200 units (approximately 11% w/w of reactants) of enzyme. Increasing amounts of geraniol inhibited lipase activity,
while excess acyl donor concentration enhanced ester production. Yields as high as 97% were obtained at 50°C, 24 h incubation,
with no added water. Solvents with logP values ≥3.0 showed the highest conversion yields. Solvent-free samples also performed well. The pH range of 4–9 gave good
yields (92–98.4%). Enzyme reuse studies showed the lipase remained active after 15 runs. 相似文献
11.
Manjeet Kumar Bhahwal A. Shah Subhash C. Taneja 《Advanced Synthesis \u0026amp; Catalysis》2011,353(8):1207-1212
The lipase Novozym435 (0.6% w/w) was used in tandem with organocatalysts in a first vinyl/isopropenyl acetate‐mediated aldol reaction. The reaction was facilitated through the lipase‐catalyzed in situ generation of acetaldehyde/acetone. The important features of the present methodology include the mild and facile reaction conditions, regenerability of the lipase, comparatively high yields and minimal side product formation. 相似文献
12.
Yuko Ikeda Ryu Nozaki Youichi Kurokawa 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2002,77(1):86-91
Lipase (EC 3.1.1.3) was immobilized on cellulose acetate–TiO2 gel fibre by the sol–gel method. The immobilized lipases were used for esterification of n‐butyric acid with n‐butyl alcohol and enantioselective acylation of (R, S)‐phenylethanol using vinyl acetate as an acyl donor. Compared with native lipase, the activity of the immobilized lipase was stable and relatively unaffected by the water content of the solvent and the substrate concentration. The data indicate that the lipases are immobilized on the fibre surface and that enzyme activity is influenced by bound water. However, the thermal reactivity and enantioselectivity of the immobilized lipase were less than those of native lipase. This may not reflect thermal inactivation of the enzyme but rather significant thermal contraction of the gel fibre by cellulose crystallization, resulting in liberation of bound water and a decrease in the amount of enzyme which is available for the reaction. Copyright © 2001 Society of Chemical Industry 相似文献
13.
A range of fatty acid esters is now being produced commercially with immobilized microbial lipases (glycerol ester hydrolases; EC) in nonaqueous solvents. In this study, a synthetic hydrogel was prepared by the copolymerization of methacrylic acid and dodecyl methacrylate in the presence of a crosslinker, N,N‐methylene bisacrylamide. A purified alkaline thermotolerant bacterial lipase from Bacillus cereus MTCC 8372 was immobilized on a poly(methacrylic acid‐co‐dodecyl methacrylate‐cl‐N,N‐methylene bisacrylamide) hydrogel by an adsorption method. The hydrogel showed a 95% binding efficiency for the lipase. The bound lipase was evaluated for its hydrolytic potential toward various p‐nitrophenyl acyl esters with various C chain lengths. The bound lipase showed optimal hydrolytic activity toward p‐nitrophenyl palmitate at a pH of 8.5 and a temperature of 55°C. The hydrolytic activity of the hydrogel‐bound lipase was enhanced by Hg2+, Fe3+, and NH ions at a concentration of 1 mM. The hydrogel‐bound lipase was used to synthesize geranyl acetate from geraniol and acetic acid in n‐heptane. The optimization of the reaction conditions, such as catalyst loading, effect of substrate concentration, solvent (n‐pentane, n‐hexane, n‐heptane, n‐octane, and n‐nonane), reaction time, temperature, molecular sieve (3 Å × 1.5 mm) and scale up (at 50‐mL level), was studied. The immobilized lipase (25 mg/mL) was used to perform an esterification in n‐alkane(s) that resulted in the synthesis of approximately 82.8 mM geranyl acetate at 55°C in n‐heptane under continuous shaking (160 rpm) after 15 h when geraniol and acetic acid were used in a ratio of 100 : 100 mM. The addition of a molecular sieve (3 Å × 1.5 mm) to the reaction system at a concentration of 40 mg/mL in reaction volume (2 mL) resulted in an increase in the conversion of reactants into geranyl acetate (90.0 mM). During the repetitive esterification under optimum conditions, the hydrogel‐bound lipase produced ester (37.0 mM) after the eighth cycle of reuse. When the reaction volume was scaled up to 50 mL, the ester synthesized was 58.7 mM under optimized conditions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
14.
Shweta Pahujani Surendra Kumar Shukla Bhawani Prasad Bag Shamsher S. Kanwar Reena Gupta 《应用聚合物科学杂志》2007,106(4):2724-2729
A purified alkaline thermotolerant bacterial lipase from Bacillus coagulans BTS‐3 was immobilized on nylon‐6 matrix activated by glutaraldehyde. The matrix showed ~ 70% binding efficiency for lipase. The bound lipase was used to perform transesterification in n‐heptane. The reaction studied was conversion of vinyl acetate and butanol to butyl acetate and vinyl alcohol. Synthesis of butyl acetate was used as a parameter to study the transesterification reaction. The immobilized enzyme achieved ~ 75% conversion of vinyl acetate and butanol (100 mmol/L each) into butyl acetate in n‐heptane at 55°C in 12 h. When alkane of C‐chain lower or higher than n‐heptane was used as an organic solvent, the conversion of vinyl acetate and butanol to butyl acetate decreased. During the repetitive transesterification under optimal conditions, the nylon bound lipase produced 77.6 mmol/L of butyl acetate after third cycle of reuse. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 相似文献
15.
Y. Kodera H. Nishimura A. Matsushima M. Hiroto Y. Inada 《Journal of the American Oil Chemists' Society》1994,71(3):335-338
Lipases from various microorganisms were chemically modified with polyethylene glycol derivatives: 2,4-bis[O-methoxypoly(ethylene glycol)]-6-chloro-s-triazine (activated PEG2, a chain-shaped polymer) and copolymer of polyoxyethylene allyl methyl diether and maleic anhydride (activated PM, a comb-shaped
polymer). Because each polymer is amphipathic, the modified lipases become soluble not only in aqueous solution but also in
hydrophobic media. They exhibit potent catalytic actions for ester synthesis and ester exchange reactions, the reverse reaction
of hydrolysis, in transparent organic solvents and also in oily substrates without organic solvents. With PEG2-lipases, macrocyclic lactone and gefarnate (geranyl farnesylacetate) were synthesized in high yields from 16-hydroxy-hexadecanoic
acid ethyl ester and from farnesylacetic acid and geraniol in organic solvents, respectively. The modified lipase catalyzed
the esterification preferentially with the (R)-isomer of secondary alcohols. Because the ester synthesis reactions with modified lipase proceeded in the transparent benzene
system, the kinetic parameters (Michaelis constant and maximum velocity) were obtained by reciprocal plotting according to
the Michaelis equation. With comb-shaped polymer as modifier, PM-lipase catalyzed effectively the reverse reaction of hydrolysis
in organic solvents. The properties of each modified lipase are discussed in relation to those of the nonmodified lipase.
Presented at the 84th Annual Meeting of the American Oil Chemists' Society held on April 25–29, 1993, in Anaheim, CA. 相似文献
16.
17.
Maha Karra-Chaabouni Sylviane Pulvin Didier Touraud Daniel Thomas 《Journal of the American Oil Chemists' Society》1998,75(12):1201-1206
The factors affecting the synthesis of geranyl butyrate by esterase 30,000 of Mucor miehei were studied in a solvent-free system. The effects of substrate molar ratio, temperature, agitation speed, and initial addition
of water were investigated. The equimolar ratio was most interesting for ester production in batch. There were no diffusion
limitations, and the reaction could be realized at low agitation. The catalytic activity of the enzyme was irreversibly deactivated
at 60°C, and the initial addition of water decreased the rate of conversion after 75 h of reaction. The enzyme activity increased
with increased linear chainlength of the acid and was also affected by the alcohol structure. Esterase 30,000 gave the highest
conversion of butyric acid with hexanol and terpenic alcohols (citronellol, nerol) and the lowest with the secondary alcohol
(2-hexanol). Finally, five other industrial enzymatic preparations were investigated for their ability to synthesize geranyl
butyrate and to hydrolyze olive oil. We observed, for the lipase from Rhizopus javanicua, that there is no relationship between hydrolytic and synthetic activities; this example shows that the hydrolytic lipase
activity data cannot predict the capability of lipases in esterification reactions. 相似文献
18.
Maha Karra-Chaabouni Sylviane Pulvin Didier Touraud Daniel Thomas 《Journal of the American Oil Chemists' Society》1998,75(9):1201-1206
The factors affecting the synthesis of geranyl butyrate by esterase 30,000 of Mucor miehei were studied in a solvent-free system. The effects of substrate molar ratio, temperature, agitation speed, and initial addition
of water were investigated. The equimolar ratio was most interesting for ester production in batch. There were no diffusion
limitations, and the reaction could be realized at low agitation. The catalytic activity of the enzyme was irreversibly deactivated
at 60°C, and the initial addition of water decreased the rate of conversion after 75 h of reaction. The enzyme activity increased
with increased linear chainlength of the acid and was also affected by the alcohol structure. Esterase 30,000 gave the highest
conversion of butyric acid with hexanol and terpenic alcohols (citronellol, nerol) and the lowest with the secondary alcohol
(2-hexanol). Finally, five other industrial enzymatic preparations were investigated for their ability to synthesize geranyl
butyrate and to hydrolyze olive oil. We observed, for the lipase from Rhizopus javanicua, that there is no relationship between hydrolytic and synthetic activities; this example shows that the hydrolytic lipase
activity data cannot predict the capability of lipases in esterification reactions. 相似文献
19.
L Kanwar S Hazarika A Goswami N
N Dutta A
K Hazarika Pranab Goswami 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2002,77(8):898-902
Isolation of a novel microbial lipase (EC 3.1.1.3) having specific catalytic activity for the synthesis of optically pure 2‐O‐benzylglycerol‐1‐acetate, the building block for the preparation of many β‐blockers, phospholipase A2 inhibitors and other biologically active compounds was the aim of this investigation. A Pseudomonas (strain G6), recently isolated from soil, produced an extracellular lipase. SDS–PAGE analysis showed that the lipase protein was a hexamer. The molecular weight of the sub‐units of the lipase protein were 10, 19, 29, 30, 47 and 53. The catalytic activity of the lipase was exploited for the synthesis of 2‐O‐benzylglycerol‐1‐acetate from 2‐O‐benzylglycerol through transesterification using vinyl acetate as acylating agent. High selectivity of the lipase towards the monoacetate product was demonstrated. A 97% enantiomeric excess (ee) of S(+)‐2‐O‐benzylglycerol‐1‐acetate was obtained when the reaction was carried out at room temperature with shaking. The lipase was highly active in anhydrous organic microenvironments and in non‐polar organic solvents with log P values above 2.5. © 2002 Society of Chemical Industry 相似文献
20.
Lisa N. Yee Casimir C. Akoh Robert S. Phillips 《Journal of the American Oil Chemists' Society》1995,72(11):1407-1408
Pseudomonas sp. lipase was immobilized by adsorption onto five supports and tested for its ability to synthesize geranyl esters by transesterification
using short-chain triacylglycerols as acyl donors. Reaction mixtures were prepared in 2 mL ofn-hexane, 0.1 M geraniol, 0.03M triacylglycerol, and 200 units of lipase, and incubated at 30°C and 200 rpm for 24 h. Overall,
glass beads were the best support. Geranyl acetate and caproate performed best with Duolite (77.5 and 95.3%, respectively).
Geranyl butyrate and caprylate performed best with polyvinylpyrrolidone, (80.2 and 95.5%, respectively). Values for nonimmobilized
enzyme also were obtained. Immobilization improved yields, with geranyl caproate exhibiting best results. 相似文献