Benzoquinones (BQ) have important functions in many biological processes. In alkaline environments, BQs can be hydroxylated at quinoid ring proton positions. Very little is known about the chemical reaction leading to these structural transformations as well as about the properties of the obtained hydroxyl benzoquinones. We analyzed the behavior of the naturally occurring 2,6-dimethoxy-1,4-benzoquinone under alkaline conditions and show that upon substitution of methoxy-groups, poly-hydroxyl-derivatives (OHBQ) are formed. The emerging compounds with one or several hydroxyl-substituents on single or fused quinone-rings exist in oxidized or reduced states and are very stable under physiological conditions. In comparison with the parent BQs, OHBQs are stronger radical scavengers and redox switchable earth-alkaline metal ligands. Considering that hydroxylated quinones appear as biosynthetic intermediates or as products of enzymatic reactions, and that BQs present in food or administered as drugs can be hydroxylated by enzymatic pathways, highlights their potential importance in biological systems.

The newest world trends in the scientific research are directed to production of secondary metabolites, their use and application. Capsaicin, the pungent principle of hot peppers is one of the best known natural compound. Nowadays, the research work is directed to the influence of capsaicin on physiological and biochemical processes of humans, animals, and recently plants as a biopesticide. Phytochemical studies of Capsicum annuum L. increase the application of secondary metabolites in pharmacy, food technology and medicine. In this paper, the possibilities of utilization of Capsicum annuum ssp. microcarpum L. for extracting capsaicin and its use as a biopesticide against the green peach aphid Myzus persicae Sulz. in pepper culture are sublimed. The content of capsaicin was evaluated spectrophotometrically, and the ability of capsaicin for acting as biopesticide was calculated according to Abbott. Results showed that oleoresin from Capsicum annuum ssp. microcarpum L. and its dilution 1:20 are the most efficient as biopesticide. From these results we can say that this kind of peppers can be used as a raw material for extraction of capsaicin, because of its high concentration and efficiency.

Germination of seeds is known to affect the nutritional composition of cold-pressed oils. This study focused on the effects of germination on the antioxidants and oxidative stability of linseed and sunflower seed oil. As hypothesized, germination led to increased antioxidant activities and tocopherol, chlorophyll and carotenoid content. Analysis revealed a 37.2 ± 3.5-fold and 11.6 ± 1.5-fold increase in polyphenol content in linseed and sunflower seed oil from germinated seeds, respectively. Using LC-HRMS/MS, profiles with up to 69 polyphenolic substances were identified in germinated seed oils for the first time. Germination promoted lipid hydrolysis, as evidenced by NMR, with overall significant decreases in triacylglycerol content leading to increased diacylglycerol and free fatty acid values. Rancimat measurements predicted a 4.10 ± 0.52-fold longer shelf-life for germinated linseed oil. This study successfully demonstrated the potential of germination to develop PUFA-rich oils with enhanced antioxidant capacity and oxidative stability.