METHODS AND RESULTS:
Phytochemical investigation of the aerial parts of the monotypic plant, Musella lasiocarpa, led to the isolation of four rare bicyclic diarylheptanoids, Musellarin B,musellarin C, musellarin D, musellarin E (2–5), two new phenylphenalenones, 2-methoxy-9-(3′,4′-dihydroxyphenyl)-1Hphenalen-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-pcoumaroylsucrose (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.
CONCLUSIONS:
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 2.3 μM, respectively. |