The biosynthesis of β-amyrin. Mechanism of squalene cyclization
نویسندگان
چکیده
منابع مشابه
Mechanism of squalene cyclization. The biosynthesis of fusidic acid.
It is generally accepted that the C-20 cation or its stabilized equivalent is an intermediate in the biosynthesis of certain triterpenes and sterols. To evaluate this hypothesis the biosynthesis of the protosterol fusidic acid was investigated. Fusidic acid was biosynthesized by incubating the fungus Fusidium coccineum on a medium containing (3RS,4R)(2-14C,4-3H)-meva10nic acid (MVA). The obtain...
متن کاملOn the mechanism of enzymatic cyclization of squalene.
The demonstration that lanosterol is formed from acetate (1) and is converted to cholesterol (2,3) has provided strong support for the hypothesis that lanosterol is an early intermediate in the conversion of squalene to cholesterol (4, 5). The cyclieation of squalene not only to lanosterol, but also to the various cyclic triterpenes, has, in fact, been postulated to proceed in a concerted manne...
متن کاملNew cyclization mechanism for squalene: a ring-expansion step for the five-membered C-ring intermediate in hopene biosynthesis.
Three triterpenes having the 6/6/5-fused tri- and 6/6/6/5-fused tetracyclic skeletons were isolated from an incubation mixture of the mutated F601A enzyme, these products being in accordance with a Markovnikov closure. Successful trapping of the tricyclic cationic intermediate by using the squalene analog having a highly nucleophilic hydroxyl group leads us to propose that the ring expansion pr...
متن کاملanalysis of reading comprehension needs of the students of paramedical studies: the case of the students of health information management (him)
چکیده ندارد.
15 صفحه اولthe effect of taftan pozzolan on the compressive strength of concrete in the environmental conditions of oman sea (chabahar port)
cement is an essential ingredient in the concrete buildings. for production of cement considerable amount of fossil fuel and electrical energy is consumed. on the other hand for generating one tone of portland cement, nearly one ton of carbon dioxide is released. it shows that 7 percent of the total released carbon dioxide in the world relates to the cement industry. considering ecological issu...
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ژورنال
عنوان ژورنال: Biochemical Journal
سال: 1968
ISSN: 0306-3283
DOI: 10.1042/bj1060659