Authentication of Platycladus Orientalis Leaves and Its Five Adulterants by Combination of Morphology and Microscopic Characteristics, TLC, and HPLC Analysis.

Background: Platycladus orientalis leaves (POL), as the source of the traditional Chinese medicine (TCM) Platycladi Cacumen, has frequently been found to be misused with five adulterants including Chamaecyparis obtusa leaves (COL), Cupressus funebris leaves (CFL), Juniperus virginiana leaves (JVL), Sabina chinensis leaves (SCL), and Juniperus formosana leaves (JFL).

Objective: The purpose of this study was to distinguish POL (fresh leaves) from its five adulterants (fresh leaves).

Methods: The micromorphological features in terms of transection and microscopic characteristics of POL and adulterants were captured and compared using the an microscope. Both HPLC and TLC methods for the simultaneous determination of six bioactive flavonoids (myricitrin, isoquercitrin, quercitrin, amentoflavone, afzelin, and hinokiflavone) have been developed.

Results: There were significant differences in microscopic features of transverse section and powders. The TLC results suggested that the spots of myricitrin in POL were more obvious than those in the five adulterants. The contents of myricitrin and quercitrin, or the total content of flavonoids in POL, determined by HPLC, were significantly higher than those in the adulterants.

Conclusion: POL was successfully distinguished from its five adulterants by the comparison of morphology, microscopic characteristics, and chemical profiles.

Highlights: This research provides a comprehensive morphology, microscopic identification, TLC, and HPLC analysis for authenticating POL and its five adulterants.