Highly Modified Sesquiterpene Lactones with Cytotoxic Activities from Strobocalyx chunii

Abstract

Three new germacranolide sesquiterpene lactones (SLs), strochunolides A−C (1−3, respectively), and a new guaianolide SL, strochunolide D (4), were isolated from Strobocalyx chunii and structurally characterized. Compound 1 is the first example of a dihomo-germacranolide SL, characterized by an unprecedented 6/10/5 tricyclic scaffold incorporating an additional fused δ-lactone C-ring. The structure of a known germacranolide SL, spicatolide C (5), was revised as its 8-epimer. Compound 3 exhibited potent in vitro cytotoxic activity against the HL-60 cell line, with an IC 50 value of 0.18 ± 0.01 μM.

Anti-Inflammatory Salicin Derivatives from the Barks of Salix tetrasperma

“…Extraction and isolation procedures were carried out according to previously reported methods. − The air-dried and powdered barks of S. tetrasperma (15 kg) were extracted with 95% EtOH (3 × 25 L, rt) to give a dried residue (1.1 kg), which was then partitioned between EtOAc and H 2 O. The EtOAc extract (270 g) was subjected to CC (D101-macroporous absorption resin) eluted with 30, 50, 80, and 95% EtOH in H 2 O to obtain four pooled fractions (Frs.…”