Scillapersicene: a new homoisoflavonoid with cytotoxic activity from the bulbs of <i>Scilla persica</i> HAUSSKN

<p>The phytochemical investigation of <i>Scilla persica</i> HAUSSKN bulbs led to the isolation of a novel homoisoflavonoid that named Scillapersicene (<b>1</b>) and identified as 3-(3′,4′-dihydroxybenzylidene)-8-hydroxy-5,7-dimethoxychroman-4-one along with five known homoisoflavonoids <b>2</b>–<b>6</b>, whose structures were elucidated using HRFAB-MS, 1D and 2D NMR spectroscopic data. The known compounds were identified as 3-(3′,4′-dihydroxybenzyl)-5,8-dihydroxy-7-methoxychroman-4-one (<b>2</b>), 3,9-dihydro-autumnalin (<b>3</b>), autumnalin (<b>4</b>), 3-(3′,4′-dihydroxybenzylidene)-5,8-dihydroxy-7-methoxychroman-4-one (<b>5</b>) and scillapersicone (<b>6</b>). All compounds obtained, expect <b>2</b> and <b>4</b>, showed strong cytotoxic activity against AGS cell line. The toxicity on AGS cell line was measured by <b>1</b>, <b>3</b>, <b>5</b> and <b>6</b> with IC₅₀ values of 8.4, 30.5, 10.7 and 24.2 μM, respectively. In addition, the physico-chemical properties of these natural compounds were optimised using density functional method (B3LYP) with standard 6-311+G* basis set. These natural products have low-energy gaps between the first ionisation potentials and highest occupied molecular orbital. In conclusion, the low-energy gap could cause reason for cytotoxic activity of homoisoflavonoids.</p