Premium
Diterpenoide Drüsenfarbstoffe aus Labiaten: 11 Coleone und Royleanone aus Coleus carnosus H ASSK
Author(s) -
Yoshizaki Fumihiko,
Rüedi Peter,
Eugster Conrad Hans
Publication year - 1979
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19790620826
Subject(s) - coleus , chemistry , plectranthus , stereochemistry , sephadex , diterpene , natural product , organic chemistry , botany , lamiaceae , enzyme , biology
Diterpenoid Leaf‐Gland Pigments: 11 Coleons and Royleanones from Coleus carnosus H ASSK . The above mentioned plant has been investigated for its leaf‐gland pigments. The following diterpenoids have been isolated (listed according to their elution from Sephadex LH‐20, SiO 2 and polyamide; in parentheses the yield of each product in g/kg dried leafs): royleanone ( 1 )/6,7‐dehydroroyleanone ( 2 ) (0.004, as a mixture); 7α‐acetyloxyroyleanone ( 3 , 0.009); a novel dimeric diterpene of hitherto unknown structure (0.03); horminone ( 4 , 0.08); 6β‐hydroxyroyleanone ( 5 , 0.04, new as a natural product); 7α‐acetyloxy‐6β‐hydroxyroyleanone ( 6 , 5.45); 6β, 7α‐dihydroxyroyleanone ( 7 , 1.20); 7α‐acetyloxy‐6β, 20‐dihydroxyroyleanone ( 8 , 0.046, a novel compound); coleon U ( 9 , 1.32); coleon V ( 10 , 13.84); carnosolone (6α, 11, 12‐trihydroxy‐6,20‐epoxymethano‐abieta‐8, 11, 13‐trien‐7‐one ( 11 ), 1.25, a novel compound). Therefore, this plant is one of the richest one in royleanones and coleons so far investigated by us (pure crystalline compounds 2,3%, estimated total amount > 3% of dry weight). Among the isolated compounds carnosolone ( 11 ) is of special interest being the first of a group of colourless diterpenoids from Coleus ‐ and Plectranthus ‐ species turning blue on TLC. Its oxydation product 12 is one of the rare 4‐acyl‐ ortho ‐quinones having high reactivity and characteristic spectral properties.