Madeiranes, a New Class of Pentacyclic Triterpenes:D-Friedo-madeir-14-en-3?-ol and -3-one,D:C-Friedomadeir-7-en-3?-ol and -3-one

Autor:	Ana M. Lobo, Hugo Wyler, David J. Williams, Maria-José U. Ferreira, Caroline A. O'Mahoney
Rok vydání:	1991
Předmět:	chemistry.chemical_classification Stereochemistry Organic Chemistry Ring (chemistry) Biochemistry Catalysis Hopanoids Inorganic Chemistry Terpene chemistry.chemical_compound chemistry Triterpene Biosynthesis Drug Discovery Physical and Theoretical Chemistry Pentacyclic Triterpenes Cyclopentane
Zdroj:	Helvetica Chimica Acta. 74:1329-1338
ISSN:	1522-2675 0018-019X
Popis:	The pentacyclic triterpenes 1a, b and 2a, b are isolated from extracts of Euphorbia mellifera Arr. Their structures, determined by X-ray analysis, are supported in part by MS, NMR, and IR data. The skeleton differs from that of representatives of the lupane or hopane class by (i) an unusual arrangement of the substituents in the cyclopentane ring E, the Me group being on C(19) and the i-Pr group in an angular position on C(17), and (ii) a cis D/E ring junction. We propose to name Die unknown pentacyclic parent ‘madeirane’, thus 1a, b and 2a, b are D-friedomadeir-14-ene and D:C-friedomadeir-7-ene derivatives. The biosynthesis of these compounds may be rationalized via ‘spirodammaranol’-cation intermediates 5 and 5′ and madeiranol cation 6, as outlined in Scheme 2.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::bcd3cde6f37d73ed2b99b629c4babff3 https://doi.org/10.1002/hlca.19910740622 Zobrazit plný text záznamu Plný text