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Diterpenoide Drüsenfarbstoffe aus Labiaten: 22 neue Coleone und Royleanone aus Plectranthus lanuginosus
Author(s) -
Schmid Jean Martin,
Rüedi Peter,
Eugster Conrad Hans
Publication year - 1982
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.19820650721
Subject(s) - chemistry , stereochemistry , epimer , plectranthus , isopropyl , botany , medicinal chemistry , lamiaceae , biology
Leaf‐gland Pigments from Labiatae : 22 Novel Diterpenoids (Coleons and Royleanones) from Plectranthus lanuginosus We report the isolation and structure elucidation of 22 novel diterpenoids (named lanugones A, B, C, D, E, F, G, H, I, J, K, K′, L, M, N, O, P, Q, R, S and (155)‐coleon C ( 28 ) and (155)‐coleon D ( 29 )) from the leaf‐glands of the above‐mentioned plant (see Table 1 ). Structurally they belong to the subgroups of royleanones and coleons with the following structural characteristics: 8‐hydroxy‐1‐methyl‐spi‐ro[2,5]oct‐5‐ene‐4,7‐diones, p ‐quinomethanes, extended (vinylogous) quinones, di‐osphenols and diketones. Compounds 28 and 29 are (15 S )‐epimers of the already known coleon C and coleon D (with (15 R )‐configuration), respectively. Furthermore, the already known 6,7‐didehydroroyleanone ( 1 ) has been isolated in small amount. The present investigation has uncovered the broadest range of diverse chromo‐phoric systems and oxydation levels so far found amongst diterpenoids in a single plant species. Most important for an understanding of the metabolic fate of an iso‐propyl group is the full range found with the following metabolic stages: isopropyl‐→ hydroxyisopropyl → dihydrofuran and spirocyclopropane → allyl‐ and 2‐hydroxypropyl groups.