Phytochemical investigation of the aerial parts of the monotypic plant,Musella lasiocarpa,led to the isolation of four rare bicyclic diarylheptanoids,musellarins B-E(2-5),two new phenylphenalenones,2-methoxy-9-(3′,4′-dihydroxyphenyl)-1H-phenalen-1-one(9),2-methoxy-9-(3′-methoxy-4′-hydroxyphenyl)-1H-phenalen-1-one(10),a new acenaphtylene derivative,trans-(1S,2S)-3-(4′-methoxyphenyl)-acenaphthene-1,2-diol(13),and two new sucrose esters,1,2′,3′,4′,6′-O-pentaacetyl-3-O-trans-p-coumaroylsucrose(16),1,2′,3′,4′,6′-O-pentaacetyl-3-O-cis-p-coumaroylsucrose(17),together with nine known compounds.In addition,(4E,6E)-1-(3′,4′-dihydroxyphenyl)-7-(4′′-hydroxyphenyl)-hepta-4,6-dien-3-one(15)was isolated for the first time from a natural source.The structures of new compounds were elucidated by analysis of their spectroscopic data.Compounds 2,6,8-10,12,and 14 were cytotoxic toward several of the human tumor cell lines(HL-60,SMMC-7721,A-549,MCF-7,and SW480).Of these,the new compound 9 was the most potent one,with IC50 values of 5.8,10.3,6.3,3.3,and 2.3μM,respectively.
Three new Lycopodium alkaloids,obscurumines C-E(1-3),along with nine known compounds,were isolated from the club moss Lycopodium obscurum L.Structures of the new compounds were determined on the basis of their spectroscopic analysis and the relative configurations of 1 were established by X-ray crystallographic analysis.All the new isolates were tested for the acetylcholinesterase(AChE)inhibitory activity.
Euglobal-IIIa (1), a novel acylphloroglucinol-sesquiterpene derivative, and a known analogue, have been isolated from leaves of Eucalyptus robusta. The structures was elucidated by extensive spectroscopic data and by comparison with data reported in literature, while the absolute configuration of 1 was determined by the X-ray diffraction analysis. Compound 1 exhibited comparable cytotoxicity with that of cisplatin against five human cancer cell lines HL-60, SMMC-7721, A-549, MCF-7, and SW480 with IC50 values of 15.7, 15.5, 17.6, 14.3, and 21.8 μM, respectively.
