In this research, twenty-four hydrazide–hydrazones of 2,4-dihydroxybenzoic acid were designed, synthesized, and subjected to in vitro and in vivo bioactivity studies. The chemical structure of the obtained compounds was confirmed by spectral methods. Antimicrobial activity screening was performed against a panel of microorganisms for all synthesized hydrazide–hydrazones. The performed assays revealed the interesting antibacterial activity of a few substances against Gram-positive bacterial strains including MRSA—Staphylococcus aureus ATCC 43300 (compound 18: 2,4-dihydroxy-N-[(2-hydroxy-3,5-diiodophenyl)methylidene]benzohydrazide—Minimal Inhibitory Concentration, MIC = 3.91 µg/mL). In addition, we performed the in vitro screening of antiproliferative activity and also assessed the acute toxicity of six hydrazide–hydrazones. The following human cancer cell lines were used: 769-P, HepG2, H1563, and LN-229, and the viability of the cells was assessed using the MTT method. The HEK-293 cell line was used as a reference line. The toxicity was tested in vivo on Danio rerio embryos using the Fish Embryo Acute Toxicity (FET) test procedure according to OECD No. 236. The inhibitory concentration values obtained in the in vitro test showed that N-[(4-nitrophenyl)methylidene]-2,4-dihydroxybenzhydrazide (21) inhibited cancer cell proliferation the most, with an extremely low IC50 (Inhibitory Concentration) value, estimated at 0.77 µM for LN-229. In addition, each of the compounds tested was selective against cancer cell lines. The compounds with a nitrophenyl substituent were the most promising in terms of inhibition cancer cell proliferation. The toxicity against zebrafish embryos and larvae was also very low or moderate.

中文翻译：

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2,4-二羟基苯甲酸酰肼-腙的设计、合成及体内外生物活性研究


在这项研究中，设计、合成了24种2,4-二羟基苯甲酸酰肼-腙，并进行了体外和体内生物活性研究。通过光谱方法确认了所得化合物的化学结构。针对一组微生物对所有合成的酰肼-腙进行抗菌活性筛选。进行的测定揭示了一些物质对革兰氏阳性细菌菌株的有趣抗菌活性，包括 MRSA - 金黄色葡萄球菌 ATCC 43300（化合物 18：2,4-二羟基-N-[(2-羟基-3,5-二碘苯基）亚甲基） ]苯甲酰肼 - 最低抑制浓度，MIC = 3.91 µg/mL）。此外，我们还进行了抗增殖活性的体外筛选，并评估了六种酰肼-腙的急性毒性。使用以下人类癌细胞系：769-P、HepG2、H1563和LN-229，并使用MTT方法评估细胞的活力。 HEK-293细胞系用作参考系。根据 OECD 第 236 号，使用鱼类胚胎急性毒性 (FET) 测试程序，在斑马鱼胚胎上进行体内毒性测试。体外测试中获得的抑制浓度值表明，N-[(4-硝基苯基)亚甲基] -2,4-二羟基苯甲酰肼 (21) 对癌细胞增殖的抑制作用最强，其 IC50（抑制浓度）值极低，LN-229 估计为 0.77 µM。此外，每种测试的化合物都对癌细胞系具有选择性。具有硝基苯基取代基的化合物在抑制癌细胞增殖方面最有希望。对斑马鱼胚胎和幼虫的毒性也非常低或中等。