Alkaloids from twigs and leaves of Picrasma quassioides

Objective To study alkaloids from the twigs and leaves of Picrasma quassioides. MethodsCompounds were isolated and purified by column chromatography over Sephadex LH-20 and silica gel column. Their chemical structures were elucidated on the basis of physicochemical properties and spectral data. Results Sixteen alkaloids were isolated, purified, and identified as: 5-methoxycanthin-6-one (Ⅰ), 11-hydroxycanthin-6-one (Ⅱ), canthin-6-one (Ⅲ), 4, 5-dimethoxycanthin-6-one (Ⅳ), 4-methoxy-5-hydroxycanthin-6-one (Ⅴ), 3-methylcanthin-2, 6-dione (Ⅵ), 1-formyl-4-methoxy-β-carboline (Ⅶ), 1-methoxy-β-carboline (Ⅷ), 1-ethyl-4, 8-dimethoxy-β-carboline (Ⅸ), 1-methoxycarbonyl-4-hydroxyl-β-carboline (Ⅹ), 1-methyl-4-methoxy-β-carboline (Ⅺ), 1-ethoxycarbonyl-β-carboline (ⅩⅡ), 1-formyl-β-carboline (ⅩⅢ), 1-methoxycarbonyl-β-carboline (ⅩⅣ), 1-ethyl-4-methoxy-β-carboline (ⅩⅤ), and 1, 2, 3, 4-tetrahydro-1, 3, 4-trioxo-β-carboline (ⅩⅥ). Conclusion Compound Ⅺ is separated from the natural plant for the first time and compounds Ⅱ, Ⅷ, and ⅩⅤ are separated from plants of Picrasma Bl. for the first time.