五种先前未描述的吲哚生物碱，maeruines A-E (1-5)，带有亚氨基-2H-噻吩并[2,3-b]吲哚-3(8H)-1 骨架，是从 Maerua siamensis 的茎中获得的。使用光谱技术 [NMR、MS、IR 和 UV] 和单晶 X 射线衍射阐明了它们的化学结构。 Maeruine D (4) 在体外表现出选择性环氧合酶-2 (COX-2) 抑制活性，IC50 为 29.72 ± 6.36 μM。分子动力学模拟表明，maeruine D 可以与人 COX-2 形成稳定的复合物，主要由疏水相互作用驱动。此外，Val349、Leu352、Leu384、Val523和Ala527等五个氨基酸残基被鉴定为热点残基，这可能导致高结合亲和力和选择性。此外，它对 HT-29 结直肠癌细胞具有细胞毒性，IC50 为 29.32 ± 4.76 μM，并且在 0.1-10 μM 浓度下，显着抑制促炎细胞因子白介素-1β (IL-1β) 诱导的增殖。剂量依赖性方式。版权所有 © 2024 Elsevier Ltd. 保留所有权利。

Five previously undescribed indole alkaloids, maeruines A-E (1-5), bearing imino-2H-thieno[2,3-b]indol-3(8H)-one skeleton, were obtained from the stems of Maerua siamensis. Their chemical structures were elucidated using spectroscopic techniques [NMR, MS, IR, and UV], and single-crystal X-ray diffraction. Maeruine D (4) displayed selective cyclooxygenase-2 (COX-2) inhibitory activity in vitro with an IC50 of 29.72 ± 6.36 μM. Molecular dynamics simulations revealed that maeruine D could form a stable complex with human COX-2, predominantly driven by hydrophobic interactions. In addition, five amino-acid residues including Val349, Leu352, Leu384, Val523, and Ala527 were identified as hot-spot ones, which may lead to high binding affinity and selectivity. Furthermore, it exhibited cytotoxicity against HT-29 colorectal cancer cells with an IC50 of 29.32 ± 4.76 μM, and, at 0.1-10 μM, significantly inhibited their proliferation, induced by the proinflammatory cytokine interleukin-1β (IL-1β), in a dose-dependent manner.Copyright © 2024 Elsevier Ltd. All rights reserved.