Composition and Identity Tests for the Medicinal Orchid Cyrtopodium macrobulbon

The fresh pseudobulbs of the orchid Cyrtopodium macrobulbon are commonly sold in Mexican markets for the treatment of urinary ailments. However, the quality control procedures for this species have not been established yet. Herein, we describe the chromatographic profiles, chemical markers and composition test for this widely used plant. Phytochemical investigation revealed that the more relevant compounds were a few phenanthrenes [5,7-dimethoxy-9,10-dihydrophenanthrene-2,6-diol (1; ephemeranthol B), 1,5,7-trimethoxy-phenanthrene-2,6-diol (confusarin) and 1,5,7-trimethoxy-9,10-dihydrophenanthrene-2,6-diol], two bibenzyls [(3,4'-dihydroxy-3',5-dimethoxy bibenzyl (gigantol), 4-methoxy-benzyl alcohol, and 3,3'-dihydroxy-5-methoxy bibenzyl (batatasin III)] and a series of n-alkyl-p-coumaric acid esters including tetracosyl, hexacosyl, octacosyl and triacontyl-trans-p-coumarates. A reliable and accurate analytical HPLC method for quantifying 1, selected as the active marker, was developed and validated. In addition, the botanical microscopic description was established. Altogether, the information described will be useful for integrating the pharmacopeic monograph of this plant.