Polyoxygenated cyclohexene derivatives and other constituents of Uvaria rufa stem

Abstract

Six undescribed compounds, uvarirufols D and E, (+)-uvarigranol B, (-)-uvarigranol E, 6-acetoxy-5-hydroxy-7-methoxyflavanone and cherrevenaphthalene D, along with twelve known compounds, including polyoxygenated cyclohexenes, flavonoids, and lignans, were isolated from the methanol extract of Uvaria rufa stems. Their structures were elucidated by spectroscopic analyses and the absolute configurations were determined using electronic circular dichroism. Several isolates were evaluated for cytotoxic, antitubercular and anti-inflammatory potentials. (-)-6-Acetylzeylenol showed moderate inhibitory activity against Mycobacterium tuberculosis, with MIC value of 47.10 μg/mL. Cherrevenaphthalene D exhibited weak antimycobacterial activity and potent inhibitory effect on lipopolysaccharide-induced nitric oxide (NO) production in RAW 264.7 cells (EC₅₀ = 8.54 μM). 8-Hydroxy-5,7-dimethoxyflavanone displayed moderate level of NO inhibition (EC₅₀ = 43.62 μM) with little cytotoxicity. The polyoxygenated cyclohexenes and lignans were inactive against HCT 116 and 22Rv1 cancer cells (IC₅₀ > 100 μM).

Keywords: Annonaceae; Anti-inflammatory; Antimycobacterial; Cytotoxicity; Polyoxygenated cyclohexenes; Uvaria rufa.