ISSN:
0018-019X
Schlagwort(e):
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Mimulaxanthin, the Main Carotenoid in Lamium montanum, Determination of its Absolute Configuration. Absolute Configuration of Deepoxyneoxanthin by its Correlation with NeoxanthinThe carotenoid mixture isolated from the yellow flowers of Lamium montanum PERS. (Labiatae) consists of more than 75% of carotenoids with allenic end groups. Besides 32% of neoxanthin/neochrome we isolated 44% of mimulaxanthin (1a), a very rare carotenoid so far only found in Mimulus sp. (Scrophulariaceae). Its absolute configuration was determined by oxidative degradation to the known ketone 3 (‘grasshopper ketone’) and by spectroscopic and chiroptical comparisons with neoxanthin (6). Mimulaxanthin (1a) therefore is (3S, 5R, 6R, 3′S, 5′R, 6′R)-6,7,6′,7′-tetradehydro-5,6,5′,6′-tetrahydro-β, β-carotene-3,5,3′,5′-tetraol. Deep-oxyneoxanthin, which was reisolated from Mimulus sp. is (3S, 5R, 6R, 3′R)-6,7-didehydro-6,7-dihydro-β, β-carotene-3,5,3′-triol (2), as shown by spectroscopic and chemical correlation with neoxanthin (6; de-epoxydation by BuLi/FeCl3).
Zusätzliches Material:
3 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/hlca.19800630848
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