Biotransformation of Digitoxin in Cell Cultures of Capsicum frutescens in the Presence of beta-cyclodextrin

Cell suspension cultures of Capsicum frutescens accumulated
digoxin, purpureaglycoside A and other
unknown derivatives when digitoxin, a cardiac glycoside,
was used as a precursor. The feeding of digitoxin
complexed with b-cyclodextrin increased the accumulation
of digoxin, purpureaglycoside A and other
unknown derivatives. Control cultures (without digitoxin)
did not produce any of these metabolites. The
growth of cells was affected by both digitoxin as well as
digitoxin-b-cyclodextrin. The accumulation of purpureaglycoside
A and digoxin reached a maximum of 1241
and 374mg 100 ml21 culture on the 6th and 2nd day,
respectively, which was 3.9 and 4.5 fold higher than
cultures treated with digitoxin alone (sampled on the
13th day). The other unknown derivatives formed in
digitoxin-b-cyclodextrin fed cultures were 15 times
higher than digitoxin alone fed C. frutescens cultures.
The addition of glucose to digitoxin-b-cyclodextrin
treated cultures increased the accumulation of purpureaglycoside
A which reached a maximum of
3589mg 100 ml21 culture after 12 h incubation, which
was a 2.9 fold increase over cultures treated with
digitoxin-b-cyclodextrin alone.