Plants of the genus Monarda receive growing interest as the sources of herbal raw materials with wide range of potential applications in food, cosmetics, and phytopharmaceutical industry. This study aimed to evaluate the differences in chemical characteristics and biological activity among different organs of plants representing three underinvestigated species of this genus: Monarda bradburiana L. C. Beck, Monarda × media Willd., and Monarda punctata L. The content of phenolic compounds and the antioxidant activity of leaves, stems, and inflorescences were determined. Essential oil (EO) content, composition, and antimicrobial activity were also examined. M. punctata leaves and inflorescences had the highest EO content (4.43% and 5.59%, respectively), with carvacrol as a dominant constituent. Leaf EO was also rich in thymoquinone (17.48%). In EOs of M. bradburiana and M. × media, thymol dominated. EOs inhibited the growth of all tested strains of microorganisms at a concentration of 0.625 µL × mL-1. The studied plant organs were rich in phenolic compounds, especially rosmarinic acid. M. bradburiana inflorescences were distinguished by high linarin content. Differences in flavonoid distribution seem to have special chemotaxonomic importance. Further research is needed to facilitate standardisation of the investigated plant organs as potential new herbal raw materials.

中文翻译：

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三种美国薄荷属植物的植物化学成分、抗氧化和抗菌活性：M. bradburiana LC Beck、M. × media Willd. 和 M. punctata L.

美国薄荷属植物作为草药原料的来源越来越受到人们的关注，在食品、化妆品和植物制药行业具有广泛的潜在应用。本研究旨在评估代表该属三个受调查物种：Monarda bradburiana LC Beck、Monarda × media Willd. 和 Monarda punctata L 的不同器官化学特性和生物活性的差异。酚类化合物和抗氧化剂的含量测定叶、茎和花序的活性。还检查了精油 (EO) 含量、成分和抗菌活性。点状花叶和花序的 EO 含量最高（分别为 4.43% 和 5.59%），其中香芹酚为主要成分。叶EO还富含百里醌（17.48%）。在 M. bradburiana 和 M. × media 的 EO 中，百里香酚占主导地位。 EOs 在浓度为 0.625 µL × mL-1 时抑制所有测试微生物菌株的生长。研究的植物器官富含酚类化合物，尤其是迷迭香酸。 M. bradburiana 花序的特点是高亚麻苷含量。类黄酮分布的差异似乎具有特殊的化学分类学重要性。需要进一步的研究来促进所研究的植物器官作为潜在的新草药原材料的标准化。