Descriptors :
Solanum lycopersicum , Solanum tuberosum , Solanum melongena , Solanaceae , Tracer experiment , Transamination , Tomatine , Solanine , Solasonine
Abstract :
The C-26 amino group of steroidal alkaloids, such as tomatine, is introduced during an early step of their
biosynthesis from cholesterol. In the present study, the mechanism of C-26 amination was reinvestigated
by administering stable isotope labeled compounds, such as (26,26,26,27,27,27-2H6)cholesterol during
biosynthesis of tomatine, solanine and solasonine. The chemical compositions of tomatine and solanine
so obtained were analyzed by LC–MS after administering the d6-cholesterol to a tomato seedling and a
potato shoot, respectively. The resulting spectra indicated that two deuterium atoms were eliminated
from C-26 of cholesterol during biosynthesis. Furthermore, administration of (6-13C2H3)mevalonate in
combination with lovastatin to an eggplant seedling, followed by GC–MS analysis of solasodine after
TMS derivatization established that two deuterium atoms were eliminated from C-26 of cholesterol during
solasonine biosynthesis. These findings are in contrast to an earlier observation that one hydrogen
atom was lost from C-26 during tomatidine biosynthesis, and suggest that C-26 nitrogen atom addition
involves an aldehyde intermediate. Thus, it is proposed that the C-26 amination reaction that occurs during
steroidal alkaloid biosynthesis proceeds by way of a transamination mechanism.
Title of Article :
Biosynthesis of steroidal alkaloids in Solanaceae plants: Involvement of an aldehyde intermediate during C-26 amination
Author/Authors :
Ohyama, Kiyoshi , Okawa, Akiko , Moriuchi, Yuka , Fujimoto, Yoshinori
Author/Authors - جزئيات :
