Silva Marianna C, Cunha Gracielle, Firmino Pollyana, Sallum Loide O, Menezes Antônio, Dutra Jocely, de Araujo-Neto João, Batista Alzir A, Ellena Javier, Napolitano Hamilton B
Laboratório de Novos Materiais, Universidade Evangélica de Goiás, 75083-515 Anápolis, GO, Brazil.
Laboratório de Produtos Naturais, Universidade Estadual de Goiás, 75132-903 Anápolis, GO, Brazil.
ACS Omega. 2023 Oct 18;8(43):40764-40774. doi: 10.1021/acsomega.3c05841. eCollection 2023 Oct 31.
The Cerrado biome is the world's largest and most diversified tropical savanna. Despite its diversity, there remains a paucity of scientific discussion and evidence about the medicinal use of Cerrado plants. One of the greatest challenges is the complexity of secondary metabolites, such as flavonoids, present in those plants and their extraction, purification, and characterization, which involves a wide range of approaches, tools, and techniques. Notwithstanding these difficulties, the search for accurately proven medicinal plants against cancer, a leading cause of death worldwide, has contributed to this growing area of research. This study set out to extract, purify, and characterize 3--methylquercetin isolated from the plant A.St.-Hil. (Loganiaceae) and to test it for antiproliferative activity and selectivity against different tumor and nontumor human cell lines. A combined-method approach was employed using H and C nuclear magnetic resonance, thermogravimetric analysis, differential scanning calorimetry, single-crystal X-ray diffraction, Hirshfeld surface analysis, and theoretical calculations to extensively characterize this bioflavonoid. 3--methylquercetin melts around 275 °C and crystallizes in a nonplanar conformation with an angle of 18.02° between the pyran ring (C) and the phenyl ring (B), unlike quercetin and luteolin, which are planar. Finally, the in vitro cytotoxicity of 3--methylquercetin was compared with data from quercetin, luteolin, and cisplatin, showing that structural differences influenced the antiproliferative activity and the selectivity against different tumor cell lines.
塞拉多生物群落是世界上最大且最多样化的热带稀树草原。尽管其具有多样性，但关于塞拉多植物药用价值的科学讨论和证据仍然匮乏。最大的挑战之一是这些植物中存在的次生代谢产物（如黄酮类化合物）的复杂性及其提取、纯化和表征，这涉及到广泛的方法、工具和技术。尽管存在这些困难，但寻找经准确验证的抗癌药用植物（癌症是全球主要死因之一）推动了这一研究领域的不断发展。本研究旨在从植物A.St.-Hil.（马钱科）中提取、纯化和表征3-甲基槲皮素，并测试其对不同肿瘤和非肿瘤人类细胞系的抗增殖活性和选择性。采用了一种联合方法，利用氢和碳核磁共振、热重分析、差示扫描量热法、单晶X射线衍射、 Hirshfeld表面分析和理论计算来全面表征这种生物黄酮。3-甲基槲皮素在约275°C熔化，以非平面构象结晶，吡喃环（C）和苯环（B）之间的夹角为18.02°，这与槲皮素和木犀草素的平面构象不同。最后，将3-甲基槲皮素的体外细胞毒性与槲皮素、木犀草素和顺铂的数据进行比较，结果表明结构差异影响了抗增殖活性和对不同肿瘤细胞系的选择性。
