Cytotoxic sesquiterpene lactones from Pseudoelephantopus spicatus.

Five new sesquiterpene lactones, spicatolides D-H (1-5), along with four known compounds, pitocarphin D (6), 8 alpha-acetoxy-10 alpha-hydroxy-13-O-methylhirsutinolide (7), spicatolide A (8), and 13-O-methylvernojalcanolide 8-O-acetate (9), were isolated from an ethyl acetate extract of the aerial parts of Pseudoelephantopus spicatus. The structures of the new compounds were elucidated on the basis of spectroscopic data interpretation. All of the compounds isolated were evaluated for their cytotoxic effects against five human cancer cell lines.

New sesquiterpene lactones from the aerial parts of Pseudoelephantopus spicatus.

Two new sesquiterpene lactones, spicatolide C (1) and spicatocadinanolide A (2), have been isolated along with the known piptocarphol isomers (3, 4) and one eudismane type sesquiterpene (5) from the EtOAc extract of the aerial parts of Pseudoelephantopus spicatus. The structures and the relative stereochemistries of the new metabolites were determined by spectroscopic methods.

Anti-inflammatory and cytotoxic diterpenes from formosan Polyalthia longifolia var. pendula.

A new clerodane diterpenoid 16-hydroxycleroda-13-ene-15,16-olide-3-one (1) was isolated from the bark of Polyalthia longifolia var. pendula, along with 23 known compounds and phytosteroids. Among these compounds, 5 - 7, 10, and 24 were obtained for the first time from the family Annonaceae .

Three new agarofuran sesquiterpenes reissantins F-H from Reissantia buchananii.

Three new agarofuran sesquiterpenes, reissantins F-H, were isolated from a methanol extract of Reissantia buchananii. Their structures as well as their relative stereochemistry were established on the basis of modern mass and spectroscopic methods. Compounds were assayed for cytotoxicity against HepG2 and Hep3B human liver cancer cell lines.

New cytotoxic furanosesterterpenes from an Okinawan marine sponge, Ircinia sp.

Five new sesterterpenes have been isolated from a lipophilic extract of a sponge, Ircinia sp., and their structures elucidated by spectroscopic and chemical methods. The absolute configurations of two metabolites (1, 3) were established by chemical degradation.