Chromatographical profiles and microscopical characteristics of four Callicarpa species leaf samples collected in Thailand

The genus Callicarpa is a large and widespread genus in the family Lamiaceae. In Thailand, 12 species of Callicarpa have been identified with the presence of remarkable therapeutic effects, such as the treatment of abdominal troubles, amenorrhea, wounds, and asthma. Phytochemical and microscopical profiles of the leaf samples from four Callicarpa plants in Thailand; C. arborea Roxb., C. candicans (Burm. f.) Hochr., C. longifolia Lam., and C. rubella Lindl. were evaluated by chromatographic and microscopic techniques. Thin layer chromatographic (TLC) and high performance liquid chromatographic (HPLC) analysis suggested that all Callicarpa leaf methanol extracts showed similar chromatographic patterns with the major compounds corresponding to oleanolic acid and β-sitosterol. Only the leaf extract from C. candicans showed the presence of callicarpone, the compound that was previously reported to promote strong piscicidal effect. Microscopic analysis of plant powders showed that all selected Callicarpa leaf samples contained similar preliminary cells including epidermis, trichomes, fragments of lamina, and mesophyll layers. Six types of trichome; uni- and multi-cellular covering, stellate, candelabra, biramous/two-armed, and peltate glandular trichomes were found in these four selected Callicarpa leaves in different sizes and amounts. Therefore, the number, size, and type of the trichome could be used to differentiate Callicarpa species by microscopic technique. The information about the chromatographic fingerprints and microscopic characteristics from this study could be a guidance for quality control and setting up the specification of Callicarpa plant raw materials and extracts in the future.