Constituents from leaves of Macaranga hemsleyana

To study constituents of the leaves of Macaranga hemsleyana, and evaluate their inhibitory effects against NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome activation, and antiproliferative activity.

The constituents were isolated and purified by column chromatography on MCI gel CHP20P/P120, silica gel, Sephadex LH-20, and HPLC. The structures of compounds were determined by 1D, 2D NMR, and HR-ESI-MS data. The inhibitory effect of compounds on inflammasome activation was determined by lactate dehydrogenase (LDH) procedure. The antiproliferative activity was evaluated using MTT assay.

The study led to the isolation of 23 compounds, including one new compound, identified as (2Z)-3-[4-(β-D-glucopyranosyloxy)-2'-hydroxy-5'-methoxyphenyl]-2-propenoic acid (1), together with 22 known compounds recognized as 1,4-dihydro-4-oxo-3-pyridinecarbonitrile (2), methyl 4-methoxynicotinate (3), 4-methoxynicotinonitrile (4), 1-(3-O-β-D-glucopyranosyl-4,5-dihydroxyphenyl)-ethanone (5), neoisoastilbin (6), isoastilbin (7), aromadendrin (8), neoastilbin (9), astilbin (10), quercitrin (11), neoschaftoside (12), apigenin 6,8-bis-C-α-L-arabinoside (13), vitexin (14), bergenin (15), scopoletin (16), glucopyranoside salicyl (17), koaburside (18), benzyl β-D-glucoside (19), icariside B5 (20), roseoside (21), loliolide (22), and adenosine (23). The tested compounds did not show LDH inhibition nor antiproliferative activity.

Compound 1 was a new glycoside. Compounds 2 and 3 were obtained for the first time from natural source. The 22 known compounds constituted of alkaloids (2-4, 23), phenolics (5, 15, 17, 18), flavonoids (6-14), coumarin (16), benzyl glycoside (19), and norsesquiterpenes (20-22). All the compounds, 1-23, were revealed from M. hemsleyana for the first time. This is the initial uncovering of molecules 1-10, 12, 13, 17-19, and 23 from the genus Macaranga. The isolated compounds, 11, 14-16, and 20-22 established taxonomic classification of M. hemsleyana in Euphorbiaceae family. Flavonoids were outstanding as chemosystematic markers of Macaranga genus.