Morphology, anatomy, and quantitative determination of corosolic acid in Lagerstroemia calyculata Kurz in the Southeast region, Vietnam

Objectives: To describe the morphological characteristics, anatomy (stem, leaves), and quantify the corosolic acid in the leaves of Lagerstroemia calyculata Kurz collected in the Southeast region, Vietnam. Subjects and methods: Using the comparative morphological method to determine the scientific name of species. Studying the microscopic characteristics of Lagerstroemia calyculataKurz according to the research method of N. Ba (2009) [1] and quantifying the content of corosolic acid in the leaves according to the United States Pharmacopeia 2017 (USP 40), with adjustments to suit the conditions of the laboratory. Results: Lagerstroemia calyculata Kurz is tree, deciduous, height 30-35 m, smooth bark. Leaves lanceolate, lateral veins 9-11 pairs, hairy. Inflorescence paniculate, small white flowers. Capsules ovoid, 6-valved. Seeds are numerous, brown, and smooth. The stem has a bicollateral vascular bundle, conduction tissue arranged continuously, double phloem pillars and leaf veins exposed on both sides. The outer epidermis has multicellular stellate hairs. Scattered in soft tissue there are crystalline particles. Stomata are present only on the underside of leaves. The quantification of corosolic acid in three leaf samples of Lagerstroemia calyculata Kurz was from 0.05 to 0.12%. Conclusions: This study has detailed morphological, anatomical characteristics, and quantitative determination of corosolic acid in three leaf samples of Lagerstroemia calyculata Kurz collected in the Southeast region.