Biosynthesis of ß-Thujaplicin with the Cupressus Lusitanica Suspension Cell Culture

Abstract

One of wood tropolones, ß-thujaplicin, exists in heartwood of some species in Cupressaceae. Biosynthesis pathway of ß-thujaplicin has been interested because it has unique conjugated seven-membered ring and there has been no experimental evidence which suggests its biosynthesis pathway. Therefore, first of all we tried ¹⁴C-geraniol feeding experiments in order to prove that geraniol is the precursor of ß-thujaplicin. Secondary, biosynthetic pathway of isoprene unit was studied by ¹³C-glucose feeding experiments; especially, [U-¹³C]glucose gave direct evidence distinguishing gly celaldehy dep hosp hate (GAP)/pyruvate route from classical acetate/mevalonate pathway (Rohmer et al., 1993, Lichtenthaler et al., 1997). Moreover, labeied positions in ß-thujaplicin derived from [1-¹³C]-, [2-¹³C]-glucose gave the information to assume the transformation of carbon skeleton which is unique on ß-thujaplicin and it was confirmed by ¹³C-geraniol feeding experiments.