New sesquiterpenes from Litsea verticillata

Seven new sesquiterpenes, named litseagermacrane (1), 7-epi-eudesm-4(15)-ene-1α,6α-diol (2), 5-epi- eudesm-4(15)-ene-1β,6β-diol (4), litseahumulanes A (6) and B (7), and litseachromolaevanes A (11) and B (12), as well as the known compounds 7-epi-eudesm-4(15)-ene-1β,6β-diol (3), eudesm-4(15)-ene-1β,6α-diol (5), octahydro-4-hydroxy-3α-methyl-7-methylene-α-(1-methylethyl)- 1H-indene-1-methanol (8), 10-hydroxyl-15-oxo-α-cadinol (9), and aphanamol II (10), were isolated from an anti-HIV fraction of the leaves and twigs of Litsea verticillata Hance (Figure 1). Isolates 1, 4, and 12 were found to inhibit HIV-1 replication in a green fluorescent protein (GFP)-based reporter cell line (HOG.R5) with IC₅₀ values of 6.5 (27.5), 17.4 (73.1), and 28.0 (119.7) μg/mL (μM), respectively. The structures of these isolates were determined by spectral data including 1D and 2D NMR spectra. Compound 11 was confirmed by X-ray crystallographic analysis.