Efforts to isolate compounds from an Indonesian member of the ginger family, Kaempferia angustifolia, yielded three known molecules, identified as (+)-crotepoxide (1), (+)-pipoxide chlorohydrin (2), and flavokawain A (FKA, 3). All three compounds strongly inhibited triglyceride accumulation in 3T3-L1 murine pre-adipocytes at 10 µg/mL, and compounds 1 and 2 were both cytotoxic at this concentration. To determine the biological activities of natural 3, flavokawains A (3), B (4) and C (5) were synthesized. While 4 was cytotoxic, both 3 and 5 potently inhibited differentiation of murine pre-adipocytes and reduced triglyceride accumulation (EC₅₀ = 64.4 and 26.1 µM, respectively) with relatively weak cytotoxicity. Thus, the electron-donating group on the aromatic B ring may contribute to the highly selective anti-obesity activity.

中文翻译：

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Flavokawains，植物来源的查耳酮，抑制小鼠前脂肪细胞的分化

从印度尼西亚姜科成员Kaempferia angustifolia 中分离化合物的努力产生了三种已知分子，鉴定为 (+)-crotepoxide ( 1 )、(+)-pipoxide chlorohydrin ( 2 ) 和 flavokawain A (FKA, 3 ) . 所有三种化合物在 3T3-L1 小鼠前脂肪细胞中以 10 µg/mL 的浓度强烈抑制甘油三酯的积累，并且化合物1和2在该浓度下均具有细胞毒性。为了测定天然3的生物活性，合成了黄酮苷A ( 3 )、B( 4 )和C( 5 )。虽然4具有细胞毒性，但3和5有效抑制小鼠前脂肪细胞的分化并减少甘油三酯的积累（EC _{50 分别}为 64.4 和 26.1 µM），细胞毒性相对较弱。因此，芳族 B 环上的给电子基团可能有助于高选择性的抗肥胖活性。