Mannosyl erythritol

Yeast, Kurtzumanomyces sp. I-ll, produces mannosyl erythritol Upid (MEL) from soybean oil. MEL is a kind of biosurfactant and is classified by a glycolipid. MEL is the typical amphiphilic compound included in both lipophilic and hydrophilic moieties in the molecule. MET, is composed of mannose, erythritol, and fatty acids. Biosurfactants such as MEL have special properties over their chemically synthesized counterparts. The properties include low-toxicity, biodegradability, biological activity, a wide variety of possible structures, and ease of synthesis from inexpensive, renewable resources. Consequently, biosurfactants provide new possibilities for a wide range of industrial applications, especially the food, cosmetic, and pharmaceutical fields and chemicals for biotechnology. 

K. Nakamichi, K. Suehara, Y. Nakano, K. Kakugawa, M. Tamai, T. Yano. Measurement of the concentrations of mannosyl erythritol lipid and soya oil in the glycolipid fermentation process using near-infrared spectroscopy. J Near beared. Spectrosc 10(1) 53-61, 2002. 

In a glycolipid fermentation, mannosyl erythritol lipid (MEL) is produced from soybean oil added to a medium as a source of carbon. NIR can be used to measure the concentrations of MEL and soybean oil extracted from the fermentation process with ethyl acetate. NIR bands at 1436, 1920, and 2052 nm were assigned to MEL, and a MLR calibration equation was developed using the second derivative spectral data at 2040 and 1312 nm. Thin-layer chromatography with a flame-ionization detector (TLC/FID) was used as the reference method. The regression coefficient (R) and the standard error of calibration (SEC) were 0.994 and 0.48 g-l respectively. Absorption bands due to soybean oil were observed at 1208,1716,1766,2182, and 2302 nm and the second derivative bands at 2178 and 2090 nm were used for the calibration, yielding values of R and SEC of 0.974 and 0.77 g-l respectively. The NIR method was applied to the measurement of the concentrations of MEL and soybean oil in an actual fermentation process with good results (38). 

Scheme 8.9). The C NMR and optical rotation of trisaccharide 26 were identical to those reported by Lichtenthaler (vide supra) [36]. Crich and co-workers have also successfully applied their methodology towards the synthesis of complex P-mannan structures [48] and the mannosyl erythritol lipid MEL A [49]. 

Schizonellin A and B are the erythritol D-mannosyl glycosides (26) and (27), respectively, which are antibacterial and antifungal glycolipids obtained from Basidomy ce tes. 

---