The C-glycosylation of flavonoids in cereals.

Sakuranetin, a flavanone phytoalexin from ultraviolet-irradiated rice leaves

Juniper berry oil is stated to possess a wide spectrum of pharmacological activities and its monographs are included in some National Pharmacopoeias. The antibacterial and antifungal activity of the oil was reported by some authors. In our study we estimated the antibacterial and antifungal activity of three different juniper berry oils and their main components. All the micro-organisms used in this experiment were isolated from patients of Regional Hospital of Gdansk and some of them showed resistance against commonly used antibiotics. Only one of the oils (labelled A) revealed good antimicrobial properties. None of the single oil components was a stronger antibacterial and antifungal inhibitor than the oil A itself. Our data suggest that the antimicrobial activity of juniper oil A is the result of either the specific composition of the oil A (highest concentration of (-)-alpha-pinene, p-cymene and beta-pinene) or activity of a single non-identified compound. The presence of an adulterant in the oil was excluded.

Antibacterial and antifungal activity of juniper berry oil and its selected components.

Application of mass spectrometry for identification and structural studies of flavonoid glycosides.

Summary
A comprehensive and large-scale metabolome quantitative trait loci (mQTL) analysis was performed to investigate the genetic backgrounds associated with metabolic phenotypes in rice grains. The metabolome dataset consisted of 759 metabolite signals obtained from the grains of 85 lines of rice (Oryza sativa, Sasanishiki × Habataki back-crossed inbred lines). Metabolome analysis was performed using four mass spectrometry pipelines to enhance detection of different classes of metabolites. This mQTL analysis of a wide range of metabolites highlighted an uneven distribution of 802 mQTLs on the rice genome, as well as different modes of metabolic trait (m-trait) control among various types of metabolites. The levels of most metabolites within rice grains were highly sensitive to environmental factors, but only weakly associated with mQTLs. Coordinated control was observed for several groups of metabolites, such as amino acids linked to the mQTL hotspot on chromosome 3. For flavonoids, m-trait variation among the experimental lines was tightly governed by genetic factors that alter the glycosylation of flavones. Many loci affecting levels of metabolites were detected by QTL analysis, and plausible gene candidates were evaluated by in silico analysis. Several mQTLs profoundly influenced metabolite levels, providing insight into the control of rice metabolism. The genomic region and genes potentially responsible for the biosynthesis of apigenin-6,8-di-C-α-l-arabinoside are presented as an example of a critical mQTL identified by the analysis.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-313X.2012.04903.x

Elisabeth Besson

Papers

C-glycosylflavones from Oryza sativa

New flavonoids from Flourensia cernua

C-galactosylflavones from Polygonatum multiflorum

C-glycosylflavones from parkinsonia aculeata

C-glycosylflavones from Rhynchosia minima