Annalaura Lorenzi-Riatsch

Di-coumaroylspermidines and tri-coumaroylspermidines in anthers of different species of the genus Aphelandra

Abstract N 1 , N 5 -Di- p -coumaroylspermidine, N 5 , N 10 -di- p -coumaroylspermidine, and N 1 , N 5 , N 10 tri- p -coumaroylspermidine were isolated from anthers of Aphelandra tetragona and A. chamissoniana . The correct substitution pattern of the di-coumaroylspermidines could be identified by their specific photoisomerization to four isomers which can be separated by HPLC.

Accumulation and metabolism of the spermine alkaloid aphelandrine in roots of Aphelandra tetragona

Abstract The accumulation of the spermine alkaloid aphelandrine was studied in Aphelandra tetragona roots during one growth cycle using analytical HPLC. Highest aphelandrine accumulation with 7 mg g−1 dry wt and 9 mg g−1 dry wt was observed in root tissue 16 and 26 weeks after planting. Just before flower formation, the aphelandrine content in the roots decreases indicating remobilization of the alkaloid. An enzymatic degrading system for aphelandrine was also found in root tissue. 2(3H)-Benzoxazolinone and 6-methoxy-2(3H)-benzoxazolinone are liberated when the integrity of root cells is destroyed.

Crystal structure of mozambioside, a diterpene glycoside of Coffea pseudozanguebariae

Abstract A diterpene glycoside of the furokaurane type has been isolated from the seeds of the caffeine-free coffee species Coffea pseudozanguebariae belonging to the section Mozambicoffea. This bitter-tasting compound named mozambioside is considered to replace caffeine with respect to chemical defence. Its configuration was determined by means of X-ray diffraction analysis.