Abstract:

This study aims to study the constituents from the rhizomes of Polygonatum kingianum Coll. et & Hemsl. and screen their antitumor and anti-inflammatory activities. The chemical constituents of the ethyl acetate extract and n-butanol extract from the ethanol extract of P. kingianum rhizomes were isolated and purified using various separation techniques, including normal and negative phase silica gel column chromatography, AB-8 macroporous adsorption resin column chromatography and preparative high performance liquid chromatography. Their structures were identified by ¹H NMR, ¹³C NMR and optical rotation methods. Thirteen compounds were isolated from P. kingianum, and identified as N-trans-feruloyloctopamine (1), N-cis-feruloyloctopamine (2), N-cis-p-coumaroyloctopamine (3), N-cis-p-coumaroyltyramine (4), polygonatine A (5), nicotinamide (6), adenosine (7), S-ribalinine (8), 4-methoxy-N-methyl-2-quinolone (9), ophiopogonanone G (10), (±)-5,7-dihydroxy-6,8-dimethyl-3-(2′,4′-dihydroxybenzyl)chroman-4-one (11), 5,7-dihydroxy-6-methyl-3-(4-hydroxy-benzyl)-chromane-4-one (12), (3R)-5,7-dihydroxy-8-methyl-3-(2′-hydroxy-4′-methoxybenzyl)-chroman-4-one (13), including nine alkaloids (1-9) and four homoisoflavonoids (10-13). Compounds 1-4, 7-13 were firstly isolated from P. kingianum, while compounds 8 and 9 were isolated from genus Polygonatum for the first time. The isolated compounds were screened by cytotoxic activity against human hepatocellular carcinoma cells HepG2 and human non-small cell lung cancer cells A549 using the CCK-8 assay, and the anti-inflammatory activity by lipopolysaccharide-induced mouse macrophage (RAW 264.7) model. The results showed that compounds 10, 12 and 13 had inhibitory effects on both cancer cell lines, with relatively strong inhibitory effect on A549. Among them, compound 13 had a notable inhibitory effect with IC₅₀ values of 17.99±1.45 μmol/L. Compound 10-13 could inhibit the release of NO, and compound 11 showed good potential anti-inflammatory activity, and the NO inhibition rate (91.16%±3.51%) at 16 μmol/L was better than that of the positive drug dexamethasone (64.81%±1.71%).

Key words: Polygonatum kingianum; chemical compositions, alkaloids, homoisoflavonoids, antitumor; anti-inflammatory