Records of Natural Products

A new naturally occurring diarylheptanoid, (1E,4Z,6E)-5-hydroxy-1,7-diphenylhepta-1,4,6-trien-3-one (3), was isolated from the rhizomes of K. elegans along with six known compounds, flavokawain B (1), 5,6-dehydrokawain (2), pinocembrin (4), cardamonin (5), alpinetin (6), and crotepoxide (7), among which compound 6 had not previously been isolated from this plant species. Two chalcones, flavokawain B (1) and cardamonin (5) were active against nitric oxide (NO) radicals released from LPS-induced RAW264.7 macrophages, resulting in 91.58% and 98.68% inhibition of NO production, respectively. Furthermore, compounds 1 and 5 showed superior cytotoxicity against MCF-7 (IC50 = 23.07 and 20.84 mM) and MDA-MB-231 (IC50 = 21.77 and 26.64 mM) cell lines, respectively. In silico molecular modeling studies of the most active compounds 1 and 5 against epidermal growth factor receptors (EGFR) suggested that π–π interactions with residues on the EGFR protein contributed to their anticancer properties. The results suggest that cardamonin (5) could be a promising candidate for further development of anti-inflammatory and anticancer agents.

This study aimed to modify the essential oils of Cymbopogon flexuosus (Nees ex Steud.) W.Watson, hereafter referred to as CF, and Cymbopogon martini (Roxb.) W.Watson, hereafter referred to as CM, utilizing an acid-distillation protocol. The modification resulted in a significant reduction in the aldehyde components, Neral and Geranial, in CF, subsequently leading to the formation of the monoterpene, Cymene. Conversely, the alteration in CM decreased the proportions of the monoterpenol, Geraniol, and the ester, Geranyl acetate. These modifications enhanced the cellular safety of both CF and CM essential oils towards B16-F10 cells in vitro, increasing it by 4 to 8-fold, and concurrently improved their melanin suppression and antioxidant properties.

A new 4-hydroxyisoflavan, named lyratin D (1), was isolated from the whole plant of Solanum lyratum Thunb. Its structure and absolute configuration were elucidated through comprehensive analysis of its HR-ESI-MS, 1D and 2D NMR, and circular dichroism spectroscopy data. Compound 1 was then assessed for its cytotoxic effects on RAW264.7 murine macrophage cells, and its antioxidant activity was evaluated through DPPH assay.