Untersuchungen zum Turnover von Cardenoliden inConvallaria majalis¹,*

Abstract

In leaves of Convallaria majalis L. the cardenolide content is known to decrease towards the end of the vegetation period. However, at this stage the rate of biosynthesis is even higher than at the onset of flowering. This has been revealed by photosynthesis experiments in the presence of 14C02 and the subsequent isolation of 15 labelled cardenolides using PC, TLC and HPLC. In vitro and in vivo experiments showed that the first step in the degradative pathway of convalloside is deglucosidation yielding convallatoxin, followed by conversion into several yet unidentified degradation products other than known cardenolides of C. majalis. This indicates that the cardenolides of C. majalis are subjected to a turnover at least towards the end of the vegetation period.Einleitung

Fecal Deployment: An Alternative Way of Defensive Host Plant Cardenolide Use by Lilioceris merdigera Larvae

“…Fecal shields of chrysomelid larvae were, in other instances, reported to attract predatory and parasitic insects rather than deterring them (Schaffner and Müller 2001 ; Müller and Hilker 2004 ). In our assays five larvae with Convallaria -derived fecal shield were chosen by the ants, which may be explained by the fluctuating cardenolide content of C. majalis leaves (Schrutka-Rechtenstamm et al 1985 ), potentially leading to diminished deterrent effects in individual fecal shields. Adding the findings of the honey choice experiments, we suggest that rather apolar cardenolides from C. majalis or their derivatives in the fecal shield of L. merdigera larvae reduce predation by M. rubra .…”

The Use of Convallaria and Crataegus in the Treatment of Cardiac Dysfunction

“…[16][17][18] The Convallaria plant transforms convalloside (the basic metabolic glycoside) into convallatoxin and other cardiac glycosides. 19 Convallatoxin affects vasoconstriction and vasodilation, 20 and cardiac stroke volume, pulse pressure and cAMP activity are all enhanced by Convallaria. 21 Convallamaroside may reduce angiogenesis and have anti-tumor effects.…”