Flavonoids present in the leaves of lotus (Nelumbo nucifera) grown in different regions of South Korea (Yeongcheon, Haenam, and Seocheon) and at different harvest times (July to September) were determined. Flavonoid contents in lotus extracts were identified and analyzed using high-performance liquid chromatography (HPLC). The HPLC results revealed that the flavonoid contents of the lotus extracts varied at different harvesting times, with the highest content in July. Analysis of the flavonoid content in the leaves from the different regions showed the highest contents of isorhamnetin-3-O-glucoside, quercetin 3-O-glucuronide, and quercetin 3-O-glucoside in Yeongcheon, Korea, and highest contnts of rutin, myricetin, kaempferol 3-O-glucoside, and quercetin in Haenam, Korea. The HPLC method was validated and optimized to quantify quercetin 3-O-glucuronide; it showed good linearity (1000–62.5 µg/mL, r2 = 0.9999), accuracy (106%–108%), and precision (RSD ≤ 1.70%). Determination of flavonoid content in lotus is valuable for producing medicinal crops and identifying the optimal sources to increase the quantity of clinically available medicines.

中文翻译：

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优化的HPLC / UV方法验证莲花中黄酮含量的验证

确定了在韩国不同地区（永川，海南和瑞川）和不同收获时间（7月至9月）生长的荷叶（Nelumbo nucifera）中存在的类黄酮。莲花提取物中的类黄酮含量被鉴定并使用高效液相色谱法（HPLC）进行分析。HPLC结果表明，荷叶提取物中的黄酮含量在不同的收获时间有所不同，其中7月份含量最高。对来自不同地区的叶子中的类黄酮含量进行分析后发现，韩国永川的异鼠李素-3-O-葡萄糖苷，槲皮素3-O-葡萄糖醛酸苷和槲皮素3-O-葡萄糖苷含量最高，而芦丁的含量最高。韩国海南的杨梅素，山奈酚3-O-葡萄糖苷和槲皮素。对HPLC方法进行了验证和优化，以定量槲皮素3-O-葡糖醛酸苷；它显示出良好的线性（1000–62.5 µg / mL，r2 = 0.9999），准确性（106％–108％）和精度（RSD≤1.70％）。确定莲花中的类黄酮含量对于生产药用作物和确定增加临床可用药物数量的最佳来源具有重要意义。