Isolation and identification of three new phenolic furoquinoline alkaloids from Teclea verdoorniana Exell & Mendonça (Rutaceae)

Abstract

Separation of the stem bark extracts of Teclea verdoorniana Exell & Mendonça (Rutaceae) yielded three new phenolic furoquinoline alkaloids, 8-hydroxy-5-(3-methylbut-2-enyl)-6,7-methylenedioxydictamnine (tecleaverdoornine)(1), 8-hydroxy-5-(3-hydroxy-3-methylbutyl)-6,7-methylenedioxydictamnine (tecleaverdine)(7), and 8-hydroxy-6,7-methylenedioxy-dictamnine (tecleine)(8), along with known alkaloids flindersiamine and kokusaginine. The pentacyclic triterpene lupeol was also isolated in large quantities. The application of ethanolic hydrochloric acid as a selective 4-O-demethylating reagent for dictamnine-type alkaloids is discussed.