Detection and identification of complex oxylipins in meadow buttercup (Ranunculus acris) leaves

Epoxyalcohol Synthase Branch of Lipoxygenase Cascade

Oxylipins are one of the most important classes of bioregulators, biosynthesized through the oxidative metabolism of unsaturated fatty acids in various aerobic organisms. Oxylipins are bioregulators that maintain homeostasis at the cellular and organismal levels. The most important oxylipins are mammalian eicosanoids and plant octadecanoids. In plants, the main source of oxylipins is the lipoxygenase cascade, the key enzymes of which are nonclassical cytochromes P450 of the CYP74 family, namely allene oxide synthases (AOSs), hydroperoxide lyases (HPLs), and divinyl ether synthases (DESs). The most well-studied plant oxylipins are jasmonates (AOS products) and traumatin and green leaf volatiles (HPL products), whereas other oxylipins remain outside of the focus of researchers' attention. Among them, there is a large group of epoxy hydroxy fatty acids (epoxyalcohols), whose biosynthesis has remained unclear for a long time. In 2008, the first epoxyalcohol synthase of lancelet Branchiostoma floridae, BfEAS (CYP440A1), was discovered. The present review collects data on EASs discovered after BfEAS and enzymes exhibiting EAS activity along with other catalytic activities. This review also presents the results of a study on the evolutionary processes possibly occurring within the P450 superfamily as a whole.

Nostochopcerol, a new antibacterial monoacylglycerol from the edible cyanobacterium Nostochopsis lobatus

A new antibacterial 3-monoacyl-sn-glycerol, nostochopcerol (1), was isolated from a cultured algal mass of the edible cyanobacterium Nostochopsis lobatus MAC0804NAN. The structure of compound 1 was established by the analysis of NMR and MS data while its chirality was established by comparison of optical rotation values with synthetically prepared authentics. Compound 1 inhibited the growth of Bacillus subtilis and Staphylococcus aureus at MIC of 50 μg/mL and 100 μg/mL, respectively.