The genus Salvia (Lamiaceae) is a rich source of structurally diverse isoprenoids. As part of a project
aimed at the discovery of structurally new bioactive metabolites from Iranian Lamiaceae,
we studied Salvia hydrangea, a species commonly known in Persian as “Gol-e Arooneh”. The flowers of S. hydrangea are used in popular Iranian medicine as an anthelmintic and antileishmanial drug.
We previously identified several new antiplasmodial isoprenoids from this species
[1,2]. A further phytochemical investigation of the aerial parts of S. hydrangea was conducted to identify minor isoprenoids. Fractionation of the n-hexane extract by a combination of open column chromatography on silica gel and preparative
and semi-preparative RP-HPLC afforded five new isoprenoids. Their structures were
established on the basis of extensive spectroscopic analysis, including MS, 1D and
2D NMR, and X-ray crystallographic analysis and ECD for determination of absolute
configurations. Four compounds, including 1, possess a six membered ring fused at C-8, C-9, and C-24 with other carbocycles of
the scaffold while compound 2 represents a new scaffold bearing a five membered ring instead. These isoprenoids
are assumed to result from the cycloaddition of a diterpene with a monoterpene, followed
by subsequent steps of oxidation and cyclization, and they have been found so far
only in the genera Salvia and Perovskia.
Fig. 1
[1] Farimani MM, Taheri S, Ebrahimi SN, Bahadori MB, Khavasi HR, Zimmermann S, Burn
R, Hamburger M. Org Lett 2012; 14: 166 – 169
[2] Farimani MM, Bahadori MB, Taheri S, Ebrahimi SN, Zimmermann S, Burn R, Amin GR,
Hamburger M. J Nat Prod 2011; 74: 2200 – 2205
