In 1992, with the United Nations Conference on Environment and Development in Rio de Janeiro and the subsequent Convention on Biological Diversity (CBD), the world changed for the science of taxonomy. Many taxonomists appear not to have noticed this change, but it has significantly altered the political climate in which taxonomic research is undertaken. By the late 1990s it was clear that effec...

Plant domestication can have negative consequences for defensive traits against herbivores, potentially reducing the levels of chemical defenses in plants and consequently their resistance against herbivores. We characterized and quantified the defensive flavonols from multiple cultivated ecotypes with wild ancestors of murtilla, Ugni molinae Turcz, an endemic plant from Chile, at different tim...

In grapevine, flavonoids constitute one of the most abundant subgroups of secondary metabolites, influencing the quality, health value, and typicity of wines. Their synthesis in many plant species is mainly regulated at the transcriptional level by modulation of flavonoid pathway genes either by single regulators or by complexes of different regulators. In particular, bZIP and MYB factors inter...

Dioxygenase, Flavonoid Biosynthesis, Flavonols, Genetic Control, Petunia hybrida Soluble enzyme preparations from flower buds of Petunia hybrida catalyzed the conversion of dihydroflavonols to flavonols. Dihydrokaempferol and dihydroquercetin were readily converted to the respective flavonols, whereas dihydromyricetin was a poor substrate. The reaction required 2-oxoglutarate, ascorbate and Fe2...

We report here a negative ionization nanoelectrospray ionization mass spectrometry (nanoESI-MS) technique that simultaneously detects active components, terpenes and intact flavonol glycosides, and toxic ginkgolic acids in ginkgo products. Unlike the conventional methods that hydrolyze flavonol glycosides to flavonoids for analysis, this technique directly detects intact flavonol glycosides, en...

A rapid microwave-assisted hydrolysis (MAH) method is presented for the sample pretreatment of the determination of ginkgo flavonol glycosides in extracts of Ginkgo biloba L. (EGb). By this method, flavonol glycosides can be completely hydrolyzed within 2 min. After investigating the effects of solvents, acidity, microwave power, and microwave radiation time on hydrolysis, the optimal hydrolysi...

Auxin and ethylene are key regulators of plant growth and development, and thus the transcriptional networks that mediate responses to these hormones have been the subject of intense research. This study dissected the hormonal cross talk regulating the synthesis of flavonols and examined their impact on root growth and development. We analyzed the effects of auxin and an ethylene precursor on r...

In the present study, we investigated the effect of Ginkgo biloba extracts and some of its individual constituents on the catalytic activity of human cytochrome P450 enzymes CYP1B1, CYP1A1, and CYP1A2. G. biloba extract of known abundance of terpene trilactones and flavonol glycosides inhibited 7-ethoxyresorufin O-dealkylation catalyzed by human recombinant CYP1B1, CYP1A1, and CYP1A2, and human...

Spectral properties of flavonols of three varieties (Golden Delicious, Antonovka, and Renet Simirenko) of anthocyanin-free apple fruit were investigated with reflectance spectroscopy. The results of spectral and biochemical analyses suggested that fruit reflectance in a broad spectral range 365-430 nm is strongly dependent on and, in sunlit fruit surfaces, governed by flavonols. The build up of...