Damtoft S. et al. 1995

• Authors: Damtoft S.; Rosendal Jensen S.; Schacht S.
• Title: Last stages in the biosynthesis of antirrhinoside
• Location: Phytochemistry 39: 549-551 (1995)
• Abstract: Feeding experiments with 2H-labeled precursors have now shown that the last steps in the biosynthesis of antirrhinoside in Antirrhinum majus involve an initial hydroxylation of the 6-position of 6,10-dideoxyaucubin to give linaride (10-deoxyaucubin), followed by epoxidation to give 10-deoxycatalpol (5-deoxyantirrhinoside) and finally hydroxylation of the 5-positon to give antirrhinoside. 10-Deoxycatalpol was prepared by epoxidation of 10-deoxyaucubin with H2O2/WO3. Additionally, the iridoid content of two other species of Antirrhinum, namely A. speciosum and A. sicculum was investigated. In the first of these 10-deoxycatalpol was isolated for the first time from a plant together with antirrhinoside, linaride (10-deoxyaucubin) and macfadienoside. Antirrhinum sicculum contained 5-glucocyl antirrhinoside as the main iridoid together with antirrhinoside and macfadienoside.