Herein we report isolation of a new chromone alkaloid chrotacumine K (12) from fruits and a chromone glycoside schumaniofioside A (13) from leaves of Dysoxylum binectariferum Hook f. Schumaniofioside A is reported for the first time from Meliaceae family. Other known alkaloids isolated include rohitukine (1) and chrotacumine E (6). The structure of new alkaloid 12 was elucidated on the basis of extensive 1D and 2D NMR analysis, synthesis and chemical hydrolysis. Chemically, chrotacumine K (12) is a 3′-O-acetyl rohitukine which on chemical or enzymatic hydrolysis produces rohitukine. The new alkaloid 12 is also present in seeds and stem-barks of this plant. The glycoside schumaniofioside A (13) is present only in leaves, and in abundance (∼1% w/w of dried leaves). The isolated compounds and extracts were evaluated for in vitro effect on the proinflammatory cytokines (TNF-α and IL-6) in human monocytic THP-1 cells. The alkaloid 12 displayed potent inhibition (57%) of TNF-α at 0.3 µM, and was non-toxic to THP-1 cells up to 40 µM, indicating its excellent therapeutic window. Furthermore, a nitrobenzoyl ester analog 15e showed better inhibition of IL-6 than parent natural product chrotacumine K.

在这里，我们报告从水果中分离出一种新的色酮生物碱chrotacumine K（12）和从Dysoxylum binectariferum Hook f的叶中分离出一种色酮糖苷舒曼茶苷A（13）。菊苣科植物中首次报道了舒马尼磷苷A。分离出的其他已知生物碱包括罗基图宁（1）和色胺素E（6）。在广泛的1D和2D NMR分析，合成和化学水解的基础上，阐明了新生物碱12的结构。化学上，chrotacumine K（12）是一种3'- O-乙酰基罗基图因，在化学或酶促水解作用下会生成罗基图因。新生物碱12也存在于该植物的种子和茎皮中。糖苷类人卵磷脂A（13）仅存在于叶片中，并且含量丰富（干燥叶片的〜1％w / w）。评价分离的化合物和提取物对人单核细胞THP-1细胞中促炎细胞因子（TNF-α和IL-6）的体外作用。生物碱12在0.3 µM时显示出对TNF-α的有效抑制（57％），并且对高达40 µM的THP-1细胞无毒，表明了其极好的治疗窗口。此外，硝基苯甲酸酯类似物15e比母体天然产物chrotacumine K表现出更好的IL-6抑制作用。