Diterpenes and phenolic compounds from Sideritis pullulans

Phytochemical investigation of Sideritis pullulans aerial part and root extracts allowed to isolate six ent-kaurane diterpenes, two phenylpropanoids, and one coumarin, identified as 1 alpha,3 alpha,7 beta,18-tetrahydroxy-ent-kaur-16-ene (sideripullol A) (1), 3 alpha,11 alpha,18-trihydroxy-ent-kaur-16-ene (sideripullol B) (2), 3 alpha, 7 beta,18-trihydroxy-17-nor-ent-kauran-16-one (sideritone A) (3), 3 alpha,7 beta-dihydroxy-18-acetyloxy-17-nor-ent-kauran-16-one (sideritone B) (4), 3 alpha,7 beta,16 alpha,17-tetrahydroxy-18-acetyloxy-ent-kaurane (sideripullol C) (5), 7 beta,16 alpha,17,18-tetrahydroxy-ent-kaurane (sideripullol D) (6), beta-(3-methoxy-4-hydroxyphenyl)-ethyl-O-alpha-L-arabinopiranosyl-(1 -> 2)-alpha-L-rhamnopyranosyl-(1 -> 3)-6-O-t-feruloyl-beta-D-glucopyranoside (sideritiside A) (7),beta-(3,4-dihydroxyphenyl)-ethyl-O-alpha-L-arabinopiranosyl-(1 -> 2)-alpha-L-rhamnopyranosyl-(1 -> 3)-6-O-t-feruloyl-beta-D-glucopyranoside (sideritiside B) (8), and 7-demethyl-8-methoxycoumarsabin (9), respectively. Twenty known compounds, including phenolics, flavonol glycosides, iridoids, diterpenes, sesquiterpenes, lignans, coumarins, and phenylpropanoids were also isolated and characterized. All diterpenes were evaluated for their cytotoxic activity. (C) 2014 Elsevier Ltd. All rights reserved.