The authors attempted to synthesize carbohydrate esters of fatty acids enzymatically in order to overcome the problems associated with the chemical processes for the synthesis of commercial sucrose esters. The enzymes used were lipases from microorganisms belonging to Rbyzopus, Enterbacterium, Aspergillus, Pseudomonas, Cbromobacterium, Candida, Mucor and Penicillium. Fatty acids (stearic, oleic and linoleic) and carbohydrates (sucrose, glucose, fructose and sorbitol) used for the reaction were obtained from commercial sources. The enzyme reaction was performed by mixing the enzyme and the substrates in the buffer solution and incubating at 40 C; after freeze-drying the mixture, the products were extracted and subjected to thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). It was observed by TLC and HPLC that carbohydrate esters of fatty acid were produced by the enzyme reaction, and their structures were confirmed by infra red (IR) and nuclear magnetic resonance (NMR) spec-trometries~ The lipase from Candida cylindracea was the most enzyme active on the synthesis of carbohydrate esters. The optimum conditions for its activity were as follows: molar ratio of carbohydrate to fatty acid: O.05mol/1 : 0.2reel/I; amount of lipase: 4g/l; pH of the reaction mixture: 5.4 in phosphate buffer; reaction period: 72 hr.

A series of s-decyl glucopyranosides was prepared, and surface properties, such as static surface tension, critical micelle concentration (cmc), occupation area of a molecule at surface, dynamic reduction of surface tension and foaming properties, foam suppression in fermentation process using Baker's yeast, biodegradation, and antimicrobial properties were studied and compared with those of n-decyl glucopyranosides. The s-decyl glucopyranosides showed excellent surface properties and biodegradability by environmental microbes compared to The most prominent characteristics of s-decyl glucopyranosides compared to n-decyl glucopyranosides were the dynamic surface tension reduction and the foaming properties. Dynamic surface tension reduction was faster when the hydrophilic glucopyranosyl group was bonded near the center

Active antibacterial substances contained in the bark of Phyllostachys heterocycla var. Pubescens were isolated by HPLC. As a result of the identification using high-resolution MS, NMR, 13C NMR, etc., 2,6-dimethoxy-p-benzoquinone was found to be an antibacterial compound in this species of bamboo. Comparison of the antibacterial spectra of benzoquinone derivatives suggested that the antibacterial activity of benzoquinones was influenced by the type of substituted group.

Three series of D‐glucosamine derivatives containing an alkyl chain with 8 to 14 atoms, methyl 2‐acylamino‐2‐deoxy‐D‐glucopyranosides,n‐alkyl 2‐acetylamino‐2‐deoxy‐D‐glucopyranosides andn‐alkyl 2‐amino‐2‐deoxy‐D‐glucopyranoside hydrochlorides, were synthesized, and their surface properties (such as surface tension, critical micelle concentration (CMC), dynamic surface tension and foaming properties), biodegradability and antimicrobial activities were evaluated.n‐Alkyl 2‐amino‐2‐deoxy‐D‐glucopyranoside hydrochlorides containing C8 to C12 carbon chains showed surface activities, a CMC and excellent foaming properties. The α‐anomers showed a slightly lower CMC than the β‐anomers, indicating less hydrophilicity of the α‐anomers. On the other hand, glucosamine derivatives containing amide groups showed poor surface activities in water due to their lower solubilities in water. All glucosamine derivatives containing alkyl chains were biodegraded as well as conventional ethoxylated nonionics by activated sludge from the municipal sewage treatment plant. Methyl 2‐acylamino‐2‐deoxy‐D‐glucopyranosides andn‐alkyl 2‐amino‐2‐deoxy‐D‐glucopyranoside hydrochlorides showed a broader spectrum of antimicrobial activity than the correspondingn‐alkyl glucopyranosides. Among them the C12 derivatives showed the best results.

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