Effect of biostimulants on chlorophyll fluorescence parameters of broccoli (Brassica oleracea var. italica) under drought stress and rewatering

The aim of the research was to determine the influence of biostimulants amino acids and amino acids + Ascophyllum nodosum filtrate on two broccoli cultivars ‘Agassi’ and ‘Tiburon’ and their response to soil drought. The plants were watered with Ascophyllum nodosum filtrate before planting and sprayed with amino acids after planting three times. Chlorophyll fluorescence measurements were performed before, during and after stress. They showed a considerable difference in cultivars’ response to stress, with ‘Agassi’ being more sensitive. Application of biostimulants enhanced the tolerance to drought stress. Maximum photochemical efficiency of PSII was unchanged, whereas the quantum yield of electron transport and photochemical fluorescence quenching values increased and the non-photochemical fluorescence quenching decreased. Moreover, the apparent photosynthetic electron transport rate rose. Chlorophyll content index was affected by the cultivar and application of biostimulants

Target-based drug discovery through inversion of quantitative structure-drug-property relationships and molecular simulation: CA IX-sulphonamide complexes

In this work, a target-based drug screening method is proposed exploiting the synergy effect of ligand-based and structure-based computer-assisted drug design. The new method provides great flexibility in drug design and drug candidates with considerably lower risk in an efficient manner. As a model system, 45 sulphonamides (33 training, 12 testing ligands) in complex with carbonic anhydrase IX were used for development of quantitative structure-activity-lipophilicity (property)-relationships (QSPRs). For each ligand, nearly 5,000 molecular descriptors were calculated, while lipophilicity (logkw) and inhibitory activity (logKi) were used as drug properties. Genetic algorithm-partial least squares (GA-PLS) provided a QSPR model with high prediction capability employing only seven molecular descriptors. As a proof-of-concept, optimal drug structure was obtained by inverting the model with respect to reference drug properties. 3509 ligands were ranked accordingly. Top 10 ligands were further validated through molecular docking. Large-scale MD simulations were performed to test the stability of structures of selected ligands obtained through docking complemented with biophysical experiments