Two new biflavanones (1 and 2), three new bichalconoids (3–5), and 11 known flavonoid analogues (6–16) were isolated from the stem bark extract (CH₃OH–CH₂Cl₂, 7:3, v/v) of Ochna holstii. The structures of the isolated metabolites were elucidated by NMR spectroscopic and mass spectrometric analyses. The crude extract and the isolated metabolites were evaluated for antibacterial activity against Bacillus subtilis (Gram-positive) and Escherichia coli (Gram-negative) as well as for cytotoxicity against the MCF-7 human breast cancer cell line. The crude extract and holstiinone A (1) exhibited moderate antibacterial activity against B. subtilis with MIC values of 9.1 μg/mL and 14 μM, respectively. The crude extract and lophirone F (14) showed cytotoxicity against MCF-7 with EC₅₀ values of 11 μg/mL and 24 μM, respectively. The other isolated metabolites showed no significant antibacterial activities (MIC > 250 μM) and cytotoxicities (EC₅₀ ≥ 350 μM).

中文翻译：

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来自 Ochna holstii 茎皮的双黄酮、查耳酮和类黄酮类似物

两个新的biflavanones（1和2），三个新bichalconoids（3 - 5），和图11个已知的黄酮类似物（6 - 16）从干树皮提取物中分离（CH ₃ OH-CH ₂氯₂，7：3，V /v) Ochna holstii。通过核磁共振光谱和质谱分析阐明了分离的代谢物的结构。评估粗提物和分离的代谢物对枯草芽孢杆菌（革兰氏阳性）和大肠杆菌的抗菌活性（革兰氏阴性）以及对 MCF-7 人乳腺癌细胞系的细胞毒性。粗提物和holstiinone A ( 1 ) 对枯草芽孢杆菌表现出中等的抗菌活性，MIC 值分别为9.1 μg/mL 和14 μM。粗提物和洛菲隆 F ( 14 ) 显示出对 MCF-7 的细胞毒性，EC ₅₀值分别为 11 μg/mL 和 24 μM。其他分离的代谢物没有显示出显着的抗菌活性（MIC > 250 μM）和细胞毒性（EC ₅₀ ≥ 350 μM）。