115114-96-0Relevant academic research and scientific papers
d-menthol fatty acid ester derivative, application thereof and preparation method for d-menthol fatty acid ester derivative
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Paragraph 0029, (2017/08/29)
The invention belongs to the technical field of medicines and relates to a d-menthol fatty acid ester derivative, an application thereof and a preparation method for the d-menthol fatty acid ester derivative. The d-terpineol fatty acid ester is prepared through carrying out an esterification reaction on d-menthol and straight-chain fatty acid. The method comprises the steps of firstly, carrying out a reaction on fatty acid and thionyl chloride so as to prepare acyl chloride, and then, subjecting acyl chloride to a reaction with d-menthol, there by preparing the ester. The d-menthol ester is applied to external preparations such as plasters, cataplasm, ointment, gels, sprays and liniment as a penetration enhancer, so that the percutaneous absorption capacity of drugs, particularly, chiral drug enantiomers is increased; and the d-menthol ester is a very good percutaneous absorption penetration enhancer and has a broad application prospect.
Biocatalytic enantiomeric resolution of L-menthol from an eight isomeric menthol mixture through transesterification
Brady,Reddy,Mboniswa,Steenkamp,Rousseau,Parkinson,Chaplin,Mitra,Moutlana,Marais,Gardiner
scheme or table, p. 1 - 10 (2012/03/27)
The four diastereomers of menthol and their enantiomers, namely dl-menthol, dl-neomenthol, dl-neoisomenthol and dl-isomenthol, were synthesised by the hydrogenation of thymol to yield an eight isomer liquid menthol. A suitably selective lipase was sought to preferentially esterify l-menthol in organic solvent, hence simplifying separation from the diasteromeric mix through distillation. From an initial screen a commercial Pseudomonas fluorescens lipase (Amano AK) was selected, and vinyl acetate was chosen as a suitable irreversible acyl donor for transesterification. The reaction reagent ratios were optimised, and an enantiomeric excess (ee) of l-menthol of greater than 95% was reproducibly achievable at a conversion of 30% dl-menthol (0.68 M) at ≤50°C. On the basis of the composition of liquid menthol the reaction had a diastereomeric excess (de) of 82%. The enzyme was recycled 150 times in 5 ml batch reactions using liquid menthol and achieving an overall yield of 184.3 g dl-menthol/g commercial enzyme preparation. The by-product acetic acid, formed by hydrolysis of menthyl acetate, was found to cause a high degree of enzyme inactivation. The resolution reaction was scaled up 400 fold to 2 L and the enzyme recycled 38 times with an average conversion of the available l-menthol of 59% and a volumetric productivity of 1.2 g/L/h.
TiCl4 promoted menthyl ester chiral auxiliary mediated synthesis of chiral syn-β-amino esters and applications of a representative syn-β-amino ester
Periasamy, Mariappan,Selva Ganesan, Subramaniapillai,Suresh, Surisetti
experimental part, p. 385 - 392 (2010/06/21)
β-Amino esters were obtained in up to 78% yield with 72:28-96:4 diastereomeric ratios by the reaction of the chiral titanium enolate of menthyl esters, prepared using the TiCl4/Et3N reagent system with prochiral imines. A representative syn-β-amino ester derivative has been used for the resolution of racemic mandelic acid to obtain a sample with >99% ee in a single step. A representative syn-β-amino ester was converted to the corresponding N-deprotected amino ester using the Pd-C/HCOOH reagent system, and then to the corresponding β-amino acid using the glacial CH3COOH/HCl reagent system, and to the corresponding β-lactam derivative with partial epimerization by the reaction using C2H5MgBr.
Enzymatic production of l-menthol by a high substrate concentration tolerable esterase from newly isolated Bacillus subtilis ECU0554
Zheng, Gao-Wei,Yu, Hui-Lei,Zhang, Jian-Dong,Xu, Jian-He
experimental part, p. 405 - 414 (2009/11/30)
Enzymatic preparation of l-menthol has been attracting much attention in the flavor and fragrance industry. A new ideal strain, Bacillus subtilis ECU0554, which exhibited high hydrolytic activity and excellent enantioselectivity towards l-menthyl ester, has been successfully isolated from soil samples through enrichment culture and identified as Bacillus subtilis by 16S rDNA gene sequencing. The esterase extracted from B. subtilis ECU0554 (BSE) showed the best catalytic properties (E > 200) for dl-menthyl acetate among the five menthyl esters examined. Enantioselective hydrolysis of 100 mM dl-menthyl acetate at 30°C and pH 7.0, using crude BSE as biocatalyst and 10% ethanol (v/v) as cosolvent, resulted in 49.0% conversion (3 h) and 98.0% ee for the l-menthol produced, which were much better than those using commercial enzymes tested. Moreover, BSE exhibited strong tolerance against high substrate concentration (up to 500 mM), and the concentration of l-menthol produced could reach as high as 182 mM, and more importantly, the optical purity of l-menthol produced was kept above 97% ee, which were not found in previous reports. These results imply that BSE is a potentially promising bio-catalyst for the large-scale enzymatic preparation of l-menthol. Using this excellent biocatalyst, the enzymatic production of l-menthol will become a mild, efficient, inexpensive and easy-to-use "green chemistry" methodology.
Candida Rugosa lipase: Enantioselectivity enhancements in organic solvents
Persichetti, Rose A.,Lalonde, Jim J.,Govardhan, Chandrika P.,Khalaf, Nazer K.,Margolin, Alexey L.
, p. 6507 - 6510 (2007/10/03)
Chiral resolutions of carboxylic acids (1-3) and alcohol (4) were carried out through esterification or transesterification in organic solvents using cross-linked enzyme crystals (CLEC) of Candida rugosa lipase (CRL). Comparison of these results with those of crude CRL reveal significant differences. As was seen in resolution through hydrolysis, a marked improvement in enantioselectivity is realized with the CLEC. Additionally, the stability afforded the enzyme in CLEC form leads to a higher activity in organic solvent.
