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Biotransformation Products (biotransformation + products)
Selected AbstractsBiotransformation of Vermitaline by Cunninghamella echinulataHELVETICA CHIMICA ACTA, Issue 5 2008Yi-Feng Lü Abstract Biotransformation of vermitaline (1) by Cunninghamella echinulata (ACCC 30369) was carried out. Four biotransformation products were obtained and three of them were characterized as new compounds. On the basis of their NMR and mass-spectral data, their structures were characterized as 7, -hydroxyrubijervine (2), 7, -hydroxyrubijervine-7-O- , - D -galactofuranoside (3), 7, -hydroxyvermitaline (4), and 7, -hydroxyvermitaline-7-O- , - D -galactofuranoside (5). [source] In vitro biotransformation of anabolic steroids in caninesJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 2 2000Williams Forensic drug testing of anabolic steroids in racing animals is required because of the potential for steroid abuse. Often when the metabolic products of an administered compound have not been identified, the analysis and verification of the administered compound is difficult. The objective of this study was to qualitatively identify the in vitro phase I biotransformation products of anabolic steroids that have a high potential for abuse in canines. The investigated steroids included testosterone, methyltestosterone, mibolerone and boldenone. Steroid biotransformation products were generated using beagle liver microsomes and analysed by high performance liquid chromatography (HPLC)/mass spectrometry (MS) with an electrospray ionization source. Characterization of steroid metabolites was based on HPLC retention, UV and mass spectra. The major testosterone metabolites were identified as androstenedione and 6,- and 16,-hydroxytestosterone. 6,-Hydroxymethyltestosterone was identified as a major metabolite in the methyltestosterone microsomal incubations. Several mibolerone metabolites were identified as monohydroxylated mibolerones as well as an oxidized mibolerone metabolite. Boldenone metabolites were identified as monohydroxylated boldenones, oxidized boldenone, and testosterone. This information should assist in the determination of anabolic steroid use in canines through the correlation of the urinary metabolites to the administered drug. [source] Identification of 1-hydroxypyrene glucuronide in tissue of marine polychaete Nereis diversicolor by liquid chromatography/ion trap multiple mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 16 2002Anders M. B. Giessing 1-Hydroxypyrene glucuronide is identified as the single major aqueous metabolite of the tetracyclic aromatic hydrocarbon pyrene, in tissue from a deposit-feeding marine polychaete, Nereis diversicolor. Identification was performed using an ion trap mass spectrometer fitted with an atmospheric pressure chemical ionization (APCI) probe and connected to a high-performance liquid chromatography/diode array detector (HPLC/DAD) system. Besides 1-hydroxypyrene, the 339-nm UV trace of tissue samples from pyrene-exposed worms showed only one dominant peak that could be related to pyrene metabolism. Negative APCI-MS of this supposed 1- hydroxypyrene conjugate gave a characteristic signal at m/z 429 corresponding to the molecular ion of 1-hydroxypyrene glucuronide plus eluent adducts ([M,,,H,+,2H2O],). Fragmentation pathways were studied by isolating the abundant ion at m/z 429 in the ion trap and performing multiple mass spectrometric experiments (MSn). The fragmentations observed were consistent with the proposed identification. Two low intensity LC peaks that could be related to pyrene metabolism by their DAD absorption spectra were also present in the 339-nm UV chromatogram of tissue samples. However, these peaks could not be identified by their mass spectra in negative ion mode due to ion suppression by very abundant co-eluting impurities. The present method shows that LC/MSn is a fast and useful analytical tool for identification of aqueous polycyclic aromatic hydrocarbon biotransformation products in samples from relatively small marine invertebrates with limited sample preparation. Copyright © 2002 John Wiley & Sons, Ltd. [source] Regio- and Stereo-selective Bioreduction of Diketo- n -butylphosphonate by Baker's YeastCHINESE JOURNAL OF CHEMISTRY, Issue 11 2002Ke Wang Abstract A regio- and stereo-selective reduction of diketo-n-butylphosphonates by baker's yeast was reported. The chemical yield and ee value of these reactions are highly dependent on the structure of substrates. The resulting optical active hydroxyalkanephosphonates can be used as chirons for the synthesis of polyfunctional organophosphorus compounds. As useful building block, a series of ,, ,-unsaturated ketones bearing chiral hydroxy group in addition to trifluoromethyl moiety was prepared via the Homer-Wadsworth-Emmons (HWE) reaction of the biotransformation products. [source] | ||||||||||