56009-40-6Relevant articles and documents
New cytotoxic secondary metabolites from marine bryozoan Cryptosula pallasiana
Tian, Xiang-Rong,Gao, Yan-Qing,Tian, Xiao-Lin,Li, Jiao,Tang, Hai-Feng,Li, Yu-Shan,Lin, Hou-Wen,Ma, Zhi-Qing
, (2017/04/28)
A new sterol, (23R)-methoxycholest-5,24-dien-3β-ol (1), two new ceramides, (2S,3R,4E,8E)- 2-(tetradecanoylamino)-4,8-octadecadien-l,3-diol (6) and (2S,3R,2′R,4E,8E)-2-(tetradecanoylamino)- 4,8-octadecadien-l,3,2′-triol (7), together with three known sterols (2-4), a lactone (5) and two ceramides (8,9), were isolated from the marine bryozoan Cryptosula pallasiana, collected at Huang Island of China. The structures of the new compounds were elucidated by extensive spectroscopic analyses, chemical methods and quantum electronic circular dichroism (ECD) calculations. Among the isolated compounds, sterol 1 possessed a rare side chain with a methoxy group at C-23, and a double bond between C-24 and C-25. Ceramides 6 and 7 possessed 14 carbons in their long-chain fatty acid base (FAB), which were different from the normal ceramides with 16 carbons in the FAB. Moreover, compounds 5 and 8 were isolated for the first time from marine bryozoans. Compounds 1-9 were evaluated for their cytotoxicity against human tumor cell lines HL-60, Hep-G2 and SGC-7901. The results showed that lactone 5 appears to have strong cytotoxicity against the test tumor cell lines, with IC50 values from 4.12 μM to 7.32 μM, and sterol 1 displayed moderate cytotoxicity with IC50 values between 12.34 μM and 18.37 μM, while ceramides 6-9 showed weak cytotoxicity with IC50 ranging from 21.13 μM to 58.15 μM.
Gas chromatography/electron-capture negative ion mass spectrometry for the quantitative determination of 2- and 3-hydroxy fatty acids in bovine milk fat
Jenske, Ramona,Vetter, Walter
experimental part, p. 5500 - 5505 (2010/03/25)
2- and 3-hydroxy fatty acids (2- and 3-OH-FAs) are bioactive substances reported in sphingolipids and bacteria. Little is known of their occurrence in food. For this reason, a method suitable for the determination of OH-FAs at trace levels in bovine milk fat was developed. OH-FAs (and conventional fatty acids in samples) were converted into methyl esters and the hydroxyl group was derivatized with pentafluorobenzoyl (PFBO) chloride to give PFBO-O-FA methyl esters. These derivatives with strong electron affinity were determined by gas chromatography interfaced to mass spectrometry using electron-capture negative ion in the selected ion monitoring mode (GC/ECNI-MS-SIM). This method proved to be highly sensitive and selective for PFBO-O-FA methyl esters. For the analysis of samples, two internal standards were used. For this purpose, 9,10-dideutero-2-OH-18:0 methyl ester (ISTD-1) from 2-OH-18:1(9c) methyl ester as well as the ethyl ester of 3-PFBO-O-12:0 (ISTD-2) was synthesized. ISTD-1 served as a recovery standard whereas ISTD-2 was used for GC/MS measurements. The whole-sample cleanup consisted of accelerated solvent extraction of dry bovine milk, addition of ISTD 1, saponification, conversion of fatty acids into methyl esters by use of boron trifluoride, separation of the methyl esters of OH-FAs from nonsubstituted FAs on activated silica, conversion of OH-FAs methyl esters into PFBO-O-FA methyl esters, addition of ISTD-2, and measurement by GC/ECNI-MS-SIM. By this method, ten OH-FAs were quantified in bovine milk fat with high precision in the range from 0.02 ± 0.00 to 4.49 ± 0.29 mg/100 g of milk fat.
Mode of Metabolism of 1-Tetradecene by Candida Yeasts and Citrates Production
Terasawa, Masato,Takahashi, Joji
, p. 2433 - 2442 (2007/10/02)
Metabolic pathways for the oxidation of 1-tetradecene by Candida lipolytica were investigated and compared with those for Candida tropicalis in oder to elucidate the difference in the productivity of citrates reported in the previous paper.No difference was found in the pathways for the initial stage of oxidation of 1-tetradecene between the two strains, indicating that the difference in the productivity of citrates is not attributable to the metabolic pathways.The metabolic rate of 1-tetradecene with C. lipolytica was found to be much lower than that with C. tropicalis.The production of citrates was much enhanced in the presence of surfactants which were known to be stimulative for microbial metabolism of hydrocarbons and 11-15 g/liters was attained on the 6th day of cultivation.