2.2. Oxylipin profiles of M. polymorpha
The GC-MS profiles of M. polymorpha oxylipins (Fig. 1C and D) possessed a general similarity to those registered for P. patens (Fig. 1A and B). The AOS products, namely the cyclopentenones, constituted a majority. At the same time, the product patterns were not identical. Firstly, the endogenous M. polymorpha oxylipins (Fig. 1C) possessed much lower content of iso -12-OPDA (1) than P. patens . The same thing concerned the M. polymorpha oxylipins biosynthesized in vitro from the exogenous α linolenic acid (Fig. 1D). The major oxylipin in M. polymorpha profiles (Fig. 1C and D) was the cis -12-OPDA. While the iso -12-OPDA (1) content was significantly lower than in P. patens, the shorter chain homologue dinor- iso -12-OPDA (2) was more abundant (Fig. 1C and D). One more peculiarity of M. polymorpha oxylipin profiles was the presence of product 3, missing in P. patens . The mass spectrum of compound 3 is presented in Fig, 2C. It possessed M + at m/z 278 (10%), as well as the isomer 2. The spectrum well matched that described before for 2,3-dinor-12-OPDA (Weber et al., 1997). Both cyclopentenones 2 and 3 were present in M. polymorpha endogenously along with the 12-OPDA, in full agreement with the recent data (Monte et al., 2018).
[a] The value of coupling constant (J 5’,6’ = 10.9 Hz) was reconstructed by the computer simulation of the AB system signal. Попросить Булата проверить
Besides with the above-described products, M. polymorpha possessed some other oxylipins, for instance, the hydroxy fatty acids 13-HOT and 11-HHT (ca. 4:1, as estimated by the total ion current chromatogram integration). The hydroxy derivatives of arachidonic and eicosapentaenoic acids were present only at trace levels. The HPL products were significantly less abundant than in P. patens .