UHPLC-MS/MS chemical profiling, preliminary toxicity, <i>in vitro</i> antioxidant potential and antimicrobial activity of <i>Brachyotum naudinii</i> Triana flowers

Chemical compounds of <i>Brachyotum naudinii</i> Triana flowers were analyzed using UHPLC-MS/MS. Anthocyanin dry extract was obtained by accelerated solvent extraction with 70% ethanol acidified with citric acid (pH 3.18) and then spray dried. Preliminary toxicity of anthocyanin extract was evaluated using <i>Artemia salina</i> Leach, while its antioxidant capacity was measured by DPPH^• and ABTS^•+ methods, and reducing capacity was assessed using FRAP assay. Results showed the flowers comprise 39% tannins, 21% flavonol glycosides, 14% organic acids, 11% anthocyanins, 7% coumaric acid derivatives, 4% polar lipids, and 4% disaccharides. Anthocyanin extract exhibited moderate toxicity against <i>Artemia salina</i> (LC₅₀ = 106.9 ± 9.9 µg mL⁻¹) and showed inhibitory effects on DPPH^• and ABTS^•+ radicals, as well as reducing capacity in FRAP assay, though statistically different from Trolox (<i>p</i> &lt; 0.05). The flowers have demonstrated antimicrobial activity against <i>Staphylococcus aureus</i> and are a source of novel anthocyanin compounds with antioxidant potential.

本研究采用超高效液相色谱-串联质谱（UHPLC-MS/MS）对纳丁短柱花（Brachyotum naudinii）Triana的花朵化学成分进行了分析。采用经柠檬酸酸化至pH 3.18的70%乙醇作为溶剂，通过加速溶剂萃取（accelerated solvent extraction）得到花色苷干提取物，随后经喷雾干燥制得。采用卤虫（Artemia salina）Leach对该花色苷提取物的初步毒性进行评估；其抗氧化能力通过DPPH自由基（DPPH•）及ABTS自由基阳离子（ABTS•+）法测定，还原能力则采用FRAP实验（FRAP assay）进行评价。结果显示，该花朵中共含有39%的单宁、21%的黄酮醇苷类、14%的有机酸、11%的花色苷、7%的香豆酸衍生物、4%的极性脂类以及4%的二糖。该花色苷提取物对卤虫表现出中等毒性，半数致死浓度（LC₅₀）为106.9 ± 9.9 µg mL⁻¹；同时对DPPH•及ABTS•+自由基具有清除抑制作用，且在FRAP实验中展现出还原能力，但其抗氧化效果与Trolox存在统计学差异（p < 0.05）。该花朵对金黄色葡萄球菌（Staphylococcus aureus）具有抗菌活性，同时亦是一类具备抗氧化潜力的新型花色苷化合物的天然来源。