Ayapin, scopoletin and 6,7-dimethoxycoumarin from sendrobium thyrsiflorum (Reichb. f.)

Abstract

DURING the examination of plants for phenolic constituents, the orchid Dendrobium thyrsiflorum was found to contain three highly fluorescent constituents (E. C. Bate-Smith, personal communication). The substances were extracted from a leaf hydrolysate with amyl alcohol and chromatographed on Whatman No. 1 paper using several different solvent systems. All the substances concerned fluoresce strongly a light blue-violet colour which is changed to green when the paper is sprayed with 2 N sodium hydroxide. The RF values in toluene/acetic acid/water (supernatant phase from 4 : 1 : 5 vol.) were 0.15, 0.77 and 0.85 and in 6 per cent acetic acid 0.43, 0.54 and 0.61. In Forestal solvent (hydrochloric acid/acetic acid/water) and butanol/acetic acid/water the RF values were all too high to give good separation. © 1960 Nature Publishing Group.