Galic acid as a non-specific regulator of phenol synthesis and growth of regenerate plants of Corylus avellana (L.) H. Karst. and Salix alba L. in vitro

Abstract

Gallic acid is found in plant tissues in free form, as well as in the composition of complex esters and hydrolysed tannins. These phenolic compounds have significant antioxidant activity and protect plant cells from damage by free radicals. In the conditions of stress that occurs during the introduction of plants into in vitro culture, the vast majority of explants are characterised by an intensive synthesis of phenols, which quickly oxidise, polymerise, block the explants’ nutrition pathways, and cause tissue necrosis. The addition of gallic acid in millimolar concentrations to the nutrient medium reduces the risk of autointoxication of tissues by secondary metabolic products. The purpose of this study was to investigate the effect of exogenous gallic acid on organogenesis and phenolic synthesis of Salix alba and Corylus avellana plants in vitro. For this purpose, the study used methods of tissue and organ culture in vitro, spectrophotometric determination of total phenols and flavonoids in leaves, methods of dispersion and nonparametric analysis. It was established that gallic acid at a concentration of 1 mmol·l-1 in the composition of the DKW nutrient medium caused the awakening of dormant buds, stimulated the growth of shoots, and also promoted the branching of stems, the development and growth of lateral roots of Salix alba in vitro. It also inhibited the synthesis of phenols in Corylus avellana plants of the varieties ‘Tonda Romana’, ‘Tonda Gentile Dele Lange’, ‘Barcelona’, while contributing to an increase in the content of phenolic compounds in the leaves of the varieties ‘Tonda Di Giffoni’, ‘Mortarella’, and ‘Epsilon’. It was established that the varieties recommended for fruiting have a higher content of phenolic compounds (‘Tonda Gentile Dele Lange’ and ‘Tonda Di Giffoni’) compared to pollinator varieties (‘Mortarella’). Therefore, exogenous gallic acid at a concentration of 1 mmol·l-1 has the properties of a non-specific regulator of phenol synthesis in regenerating plants of hazel (Corylus avellana), which is relevant for plants with a high content of phenols, especially at the stage of their introduction into in vitro culture

Oxidation reactions of cyclopent-2-en-1-yl thiophene derivatives

“…In practice, the possibility of obtaining thiophene oxabicyclohexane derivatives varied depending on the structure of the starting materials. Thus, for 2-(cyclopent-1-en-3-yl)thiophenes, the oxidation of the double bond was easier, while for 2-(cyclopent-1-en-1-yl)-5-methyl-thiophenes it was difficult or occurred synchronously with the oxidation of sulfur in the aromatic core (30)(31)(32)(33) . Modern laboratories use molecular docking for preliminary monitoring of the biological activity of compounds examined.…”

Variable’s prediction of gap acceptance roundabout capacity model – Critical gap

“…Roundabouts have already proved their effectiveness in many countries due to their operating principle, but the capacity and safety of these junctions are determined by several factors, including terrain, road geometry, and driver behaviour. Among the key parameters that determine the operation of roundabouts, a special place belongs to the critical interval (26,27) . It is important to note that this interval can vary significantly in different areas and countries due to different driving styles, road culture, road geometry, and the location of the roundabout concerning populated areas or important infrastructure.…”