Curculigosides J-K and curcorchidihydrobenzofuran A, a dihydrobenzofuran with anti-proliferative properties from Curculigo orchioides.

Abstract

Phytochemical investigation of the rhizomes and the leaves of Curculigo orchioides led to the isolation of fourteen compounds. They consist of one undescribed dihydrobenzofuran, curcorchidihydrobenzofuran A (1), two undescribed benzyl benzoate glycosides, curculigoside J (2) and K (3), and eleven known compounds (4-14). The structures of the isolated compounds were elucidated by thorough analysis of spectroscopic (IR, NMR and ECD) and spectrometric (MS) data. Compound 1 displayed significant anti-proliferative activities against cervical cancer cells (HelaS3, IC₅₀ = 3.6 µM) and breast cancer cells (MCF-7, IC₅₀ = 13.9 µM) while showing moderate activities against lung cancer cells (A549, IC₅₀ = 29.8 µM). Importantly, it was non-toxic to Vero cells. Compound 1 also inhibited the tyrosinase enzyme in a moderate manner (IC₅₀ = 120.8 µM). Eventually, its permethylated synthetic analog 1a showed a significant suppression of lipopolysaccharide (LPS)-induced NO production in murine macrophage RAW 264.7 (IC₅₀ = 23.4 µM).