Global warming contributes to higher temperatures and reduces rainfall for most areas worldwide. The concurrent incidence of extreme temperature and water shortage lead to temperature stress damage in plants. Seeking to imitate a more natural field situation and to figure out responses of specific stresses with regard to their combination, we investigated physiological, biochemical, and metabolomic variations following drought and heat stress imposition (alone and combined) and recovery, using Mentha piperita and Catharanthus roseus plants. Plants were exposed to drought and/or heat stress (35 °C) for seven and fourteen days. Plant height and weight (both fresh and dry weight) were significantly decreased by stress, and the effects more pronounced with a combined heat and drought treatment. Drought and/or heat stress triggered the accumulation of osmolytes (proline, sugars, glycine betaine, and sugar alcohols including inositol and mannitol), with maximum accumulation in response to the combined stress. Total phenol, flavonoid, and saponin contents decreased in response to drought and/or heat stress at seven and fourteen days; however, levels of other secondary metabolites, including tannins, terpenoids, and alkaloids, increased under stress in both plants, with maximal accumulation under the combined heat/drought stress. Extracts from leaves of both species significantly inhibited the growth of pathogenic fungi and bacteria, as well as two human cancer cell lines. Drought and heat stress significantly reduced the antimicrobial and anticancer activities of plants. The increased accumulation of secondary metabolites observed in response to drought and/or heat stress suggests that imposition of abiotic stress may be a strategy for increasing the content of the therapeutic secondary metabolites associated with these plants.

There has been a spurt in the spread of microbial resistance to antibiotics due to indiscriminate use of antimicrobial agents in human medicine, agriculture, and animal husbandry. It has been realized that conventional antibiotic therapy would be less effective in the coming decades and more emphasis should be given for the development of novel antiinfective therapies. Cysteine rich peptides (CRPs) are broad‐spectrum antimicrobial agents that modulate the innate immune system of different life forms such as bacteria, protozoans, fungi, plants, insects, and animals. These are also expressed in several plant tissues in response to invasion by pathogens, and play a crucial role in the regulation of plant growth and development. The present work explores the importance of CRPs as potent antimicrobial agents, which can supplement and/or replace the conventional antibiotics. Different plant parts of diverse plant species showed the presence of antimicrobial peptides (AMPs), which had significant structural and functional diversity. The plant‐derived AMPs exhibited potent activity toward a range of plant and animal pathogens, protozoans, insects, and even against cancer cells. The cysteine‐rich AMPs have opened new avenues for the use of plants as biofactories for the production of antimicrobials and can be considered as promising antimicrobial drugs in biotherapeutics.

The title compounds 3a-j, substituted 1,5-benzothiazepines were synthesized by the condensation of variously substituted chalcones 1 and 2- aminothiophenol 2 via conventional as well as non-conventional inorganic solid support microwave irradiation methods. The non-conventional protocol offers several advantages such as simple procedure, fast reaction rate, mild reaction conditions and improved yields compared to conventional methods. The structures of the products 3a-j were established by elemental analysis, FTIR, 1H-NMR, 13C-NMR and mass spectroscopic studies. The synthesized compounds have also been evaluated for the cytotoxicity against human breast cancer cell line MDA-MB-435 with some exhibiting in vitro anti-breast cancer activities

Annonaceous acetogenins (ACG), belonging to the family Annonaceae, represent a class of bioactive compounds whose toxic effects have been reported for several species of insects. Given their insecticidal properties, we first carried out the isolation of the ACG from a Brazilian collection of the seeds of Annona squamosa (Annonaceae) and prepared their methoxy methylated (MOM) and acetylated (OAc) derivatives by chemical methods. ACG analogues were semi-synthesized and characterized by spectroscopic techniques ( 1 H and 13 C-NMR). We isolated ten natural acetogenins: squamocin, molvizarin, motrilin, rolliniastatin-2, almuñequin, cherimolin-1, cherimolin-2, annonacin, squamocin D and asiminecin. The main objective of this study is to report the antifeedant, toxic and nutritional effects of three of those natural acetogenins and their acetylated and methoxy methylated derivatives on Spodoptera frugiperda Smith (Lepidoptera: Noctuidae). The natural ACGs squamocin and molvizarin killed 100% of S. frugiperda larvae, followed by motrilin (80%). Acetylated derivatives had less toxic and nutritional effects that led to pupal mortality and adult fatal malformations. The addition of MOM derivatives to the larval diet has not toxic effects on larvae, but significantly reduces growth rate and efficiency in conversion of ingested food into biomass, affecting adult survival.

Background The emergence and spread of SARS-CoV-2 throughout the world has created an enormous socioeconomic impact. Although there are several promising drug candidates in clinical trials, none is available clinically. Thus, the drug repurposing approach may help to overcome the current pandemic. Methods The main protease (M pro ) of SARS-CoV-2 is crucial for cleaving nascent polypeptide chains. Here, FDA-approved antiviral and anti-infection drugs were screened by high-throughput virtual screening (HTVS) followed by re-docking with standard-precision (SP) and extra-precision (XP) molecular docking. The most potent drug's binding was further validated by free energy calculations (Prime/MM-GBSA) and molecular dynamics (MD) simulation. Results Out of 1397 potential drugs, 157 showed considerable affinity towards M pro . After HTVS, SP, and XP molecular docking, four high-affinity lead drugs (Iodixanol, Amikacin, Troxerutin, and Rutin) with docking energies -10.629 to -11.776 kcal/mol range were identified. Among them, Amikacin exhibited the lowest Prime/MM-GBSA energy (-73.800 kcal/mol). It led us to evaluate other aminoglycosides (Neomycin, Paramomycin, Gentamycin, Streptomycin, and Tobramycin) against M pro . All aminoglycosides were bound to the substrate-binding site of M pro and interacted with crucial residues. Altogether, Amikacin was found to be the most potent inhibitor of M pro . MD simulations of the Amikacin-M pro complex suggested the formation of a complex stabilized by hydrogen bonds, salt bridges, and van der Waals interactions. Conclusion Aminoglycosides may serve as a scaffold to design potent drug molecules against COVID-19. However, further validation by in vitro and in vivo studies are required before using aminoglycosides as an anti-COVID-19 agent.