Three new compounds with nitric oxide inhibitory activity from Tirpitzia sinensis, an ethnomedicinal plant from Southwest China

Reactive Oxygen, Nitrogen, and Sulfur Species (RONSS) as a Metabolic Cluster for Signaling and Biostimulation of Plants: An Overview

This review highlights the relationship between the metabolism of reactive oxygen species (ROS), reactive nitrogen species (RNS), and H₂S-reactive sulfur species (RSS). These three metabolic pathways, collectively termed reactive oxygen, nitrogen, and sulfur species (RONSS), constitute a conglomerate of reactions that function as an energy dissipation mechanism, in addition to allowing environmental signals to be transduced into cellular information. This information, in the form of proteins with posttranslational modifications or signaling metabolites derived from RONSS, serves as an inducer of many processes for redoxtasis and metabolic adjustment to the changing environmental conditions to which plants are subjected. Although it is thought that the role of reactive chemical species was originally energy dissipation, during evolution they seem to form a cluster of RONSS that, in addition to dissipating excess excitation potential or reducing potential, also fulfils essential signaling functions that play a vital role in the stress acclimation of plants. Signaling occurs by synthesizing many biomolecules that modify the activity of transcription factors and through modifications in thiol groups of enzymes. The result is a series of adjustments in plants' gene expression, biochemistry, and physiology. Therefore, we present an overview of the synthesis and functions of the RONSS, considering the importance and implications in agronomic management, particularly on the biostimulation of crops.

New xanthones from Canscora lucidissima and their antioxidant and NO inhibitory activities

Three new xanthone glycosides, canlucosides A - C (1 - 3), along with three known compounds (4 - 6), have been obtained and identified from the ethanol extract of Canscora lucidissima. Their structures were identified according to HR-ESI-MS, 1D, 2D NMR data, ECD measurements powered by molecular calculations and optical rotation values. Compound 6 (1-hydroxy-3,7,8-trmethoxyxanthone) was isolated from C. lucidissima for the first time. Five compounds (2-6) showed moderate antioxidant and NO inhibitory activities. Canlucosides B and C (2 and 3) showed significant antioxidant activity with IC₅₀ values of 33.64 ± 5.60 µM and 36.63 ± 4.32 µM, respectively. Canlucoside B (2) possessed a significant NO inhibitory effect with an IC₅₀ value 0.92 µM.