| Abstract
| - Six new diterpenoids were isolated from a CH2Cl2−MeOH extract of the bark of Suregada multiflora.The structures were established on the basis of one- and two-dimensional NMR and other spectroscopicstudies and chemical derivatizations. Two compounds, suregadolides C (1) and D (2), were identified asnew diterpene lactones of two antipodal series, containing a cyclopropane ring bridging C-3 and C-4 ofthe basic abietane skeleton. Suremulide A (3) was found to be a new abietene diterpene lactone.Bannaringaolide A (4), a diterpene lactone, based on a novel carbon skeleton with a seven-memberedring, possibly formed by the rearrangement of the exocyclic C-17 in ring C of an ent-pimarane framework,has also been isolated. A kaurane triol, suremulol A (5), and a kaurane diol, suremulol B (6), were alsoidentified as new metabolites.
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