title: New sesquiterpenes from Sonchus transcaspicus.
abstract: Four new eudesmanolides were isolated from the whole plant of Sonchus transcaspicus and their structures were elucidated by means of spectroscopic methods, including 2D-NMR (1H-1H COSY, HMQC, HMBC and NOESY) and NOEDS (NOE difference spectra) as 1beta-O-beta-D-glucopyranosyl-5alpha,6beta H-eudesma-3-en-12,6alpha-olide (1), 1beta-O-beta-D-glucopyranosyl-15-O-( p-hydroxyphenylacetyl)-5alpha,6beta H-eudesma-3,11(13)-dien-12,6alpha-olide (2), 1beta-O-beta-D-glucopyranosyl-(6'-O-p-hydroxyphenyl acetate)-15-O-(p-hydroxyphenylacetyl)-5alpha,6beta H-eudesma-3,11(13)-dien-12,6alpha-olide (3) and 1beta-hydroxy-15-O-(p-methoxyphenylacetyl)-5alpha,6beta H-eudesma-3,11(13)-dien-12,6alpha-olide (4). Compounds 1, 2 and 3 showed antibacterial activity against Escherichia coli and Staphylococcus aureus cells. Compounds 2 and 3 were evaluated for their in vitro cytotoxic activity against cultured SMMC-7721 (human hepatoma), HELA (human cervical carcinoma) and B-16 (murine melanoma) cells. The IC50 values for 2 were 108.0, 161.1 and 203.0 microM and those for 3 were 74.1, 117.3 and 135.0 microM, respectively. The structure-activity relationship is discussed.
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, P. R. China.
authors.forename: Yi-Feng
authors.initials: YF
authors.lastname: Han
authors.forename: Qi
authors.initials: Q
authors.lastname: Zhang
authors.forename: Kun
authors.initials: K
authors.lastname: Gao
authors.forename: Zhong-Jian
authors.initials: ZJ
authors.lastname: Jia
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000494:pharmacology*; D045744:Cell Line, Tumor / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D006801:Humans; D008826:Microbial Sensitivity Tests; D008517:Phytotherapy; D035261:Plant Components, Aerial; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D012717:Sesquiterpenes / Q000737:chemistry / Q000494:pharmacology*; D031184:Sonchus; D013211:Staphylococcus aureus / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D000972:Antineoplastic Agents, Phytogenic; D010936:Plant Extracts; D012717:Sesquiterpenes