Biosynthesis of the quinolizidine alkaloids. Incorporation of Δ¹-piperideine into matrine

Abstract

Label from [6-14C]-Δ1-piperideine is incorporated nonrandomly into the carbon skeleton of the quinolizidine alkaloid, matrine, in Sophora tetraptera and S. microphylla. The distribution of radioactivity was determined by a new chemical degradation sequence. On the basis of the results, one of two previously postulated biogenetic schemes must be discarded. A modified biogenetic scheme is presented which is consistent with the present results and also leads to the correct stereochemistry of matrine.

Revisiting anabasine biosynthesis in tobacco hairy roots expressing plant lysine decarboxylase gene by using ¹⁵N-labeled lysine

“…The reasons why the expression of La-L/ODC in tobacco hairy roots caused the symmetric labeling could be explained by several possibilities. Since La-L/ODC involves in the first step of QA biosynthesis which proceed via free cadaverine (Leeper et al 1981;Leistner and Spenser 1973). One possibility is that the La-L/ODC enzyme may not form complexes with endogenous tobacco enzymes, and therefore the cadaverine produced is further oxidized by endogenous oxidase enzymes for anabasine biosynthesis.…”

“…For QA biosynthesis, an oxidative deamination of cadaverine gives rise to 5-aminopentanal which is further cyclized into Δ 1 -piperideine, a plausible intermediate for QAs production (Bunsupa et al 2012b). Unlike biosynthesis of anabasine in tobacco, lysine is incorporated into the QAs via the symmetrical intermediate cadaverine (Leeper et al 1981;Leistner and Spenser 1973).…”

Comparative analysis of quinolizidine alkaloids from different parts of Sophora alopecuroides seeds by UPLC–MS/MS

“…It is well-known that these alkaloids are all biosynthesized through the amino acid pathway. All of these reactions are catalyzed by the corresponding enzymes [23,24]. These results may due to the fact that the relevant enzyme activities in different organs are various, and the detailed mechanism should be further studied.…”

Oryzamutaic acid A, a novel yellow pigment from an Oryza sativa mutant with yellow endosperm

“…Compounds with a similar central C 12 N 2 skeleton have been reported, but the bonds between N-2 and C-15, C-7 and C-8, and C-9 and C-10 in these compounds are reduced. [6][7][8][9][10][11] To evaluate whether oryzamutaic acid A occurs only in Hatsuyamabuki, we determined oryzamutaic acid A content in the endosperm of Hatsuyamabuki and Kinuhikari. By subjecting the aq MeOH extracts of the endosperms of Hatsuyamabuki and Kinuhikari to HPLC, we estimated the oryzamutaic acid A content in Hatsuyamabuki to be 1.4 ± 0.0 lg/g; no oryzamutaic acid A content was detected in Kinuhikari (Fig.…”