Recent progress in discovery of novel AAK1 inhibitors: from pain therapy to potential anti-viral agents.

Adaptor associated kinase 1 (AAK1), a member of the Ark1/Prk1 family of Ser/Thr kinases, is a specific key kinase regulating Thr156 phosphorylation at the µ2 subunit of the adapter complex-2 (AP-2) protein. Due to their important biological functions, AAK1 systems have been validated in clinics for neuropathic pain therapy, and are being explored as potential therapeutic targets for diseases caused by various viruses such as Hepatitis C (HCV), Dengue, Ebola, and COVID-19 viruses and for amyotrophic lateral sclerosis (ALS). Centreing on the advances of drug discovery programs in this field up to 2023, AAK1 inhibitors are discussed from the aspects of the structure-based rational molecular design, pharmacology, toxicology and synthetic routes for the compounds of interest in this review. The aim is to provide the medicinal chemistry community with up-to-date information and to accelerate the drug discovery programs in the field of AAK1 small molecule inhibitors.

Metal-free visible-light-driven cascade cyclization reaction to synthesize 2-oxindoles via benzoyl and phenylsulfinyl radicals with acrylamide derivatives.

A metal-free visible-light-driven cascade cyclization reaction to synthesize 3-methyl-3-acetophenone-2-oxindoles and 3-methyl-3-(methylsulfonyl)benzene-2-oxindoles in yields up to 96% and 99%, via benzoyl and phenylsulfinyl radicals with acrylamide derivatives is reported, respectively. Extensive studies, including gram-scale, radical capture and isotope experiments, were performed to indicate that the reaction may involve a radical process.

Recent Advances in Synergistic Antitumor Effects Exploited from the Inhibition of Ataxia Telangiectasia and RAD3-Related Protein Kinase (ATR).

As one of the key phosphatidylinositol 3-kinase-related kinases (PIKKs) family members, ataxia telangiectasia and RAD3-related protein kinase (ATR) is crucial in maintaining mammalian cell genomic integrity in DNA damage response (DDR) and repair pathways. Dysregulation of ATR has been found across different cancer types. In recent years, the inhibition of ATR has been proven to be effective in cancer therapy in preclinical and clinical studies. Importantly, tumor-specific alterations such as ATM loss and Cyclin E1 (CCNE1) amplification are more sensitive to ATR inhibition and are being exploited in synthetic lethality (SL) strategy. Besides SL, synergistic anticancer effects involving ATRi have been reported in an increasing number in recent years. This review focuses on the recent advances in different forms of synergistic antitumor effects, summarizes the pharmacological benefits and ongoing clinical trials behind the biological mechanism, and provides perspectives for future challenges and opportunities. The hope is to draw awareness to the community that targeting ATR should have great potential in developing effective anticancer medicines.

24-Epibrassinolide-induced alterations in the root cell walls of Cucumis sativus L. under Ca(NO3)2 stress.

Brassinosteroids (BRs) can effectively alleviate the oxidative stress caused by Ca(NO3)2 in cucumber seedlings. The root system is an essential organ in plants due to its roles in physical anchorage, water and nutrient uptake, and metabolite synthesis and storage. In this study, 24-epibrassinolide (EBL) was applied to the cucumber seedling roots under Ca(NO3)2 stress, and the resulting chemical and anatomical changes were characterized to investigate the roles of BRs in alleviating salinity stress. Ca(NO3)2 alone significantly induced changes in the components of cell wall, anatomical structure, and expression profiles of several lignin biosynthetic genes. Salt stress damaged several metabolic pathways, leading to cell wall reassemble. However, EBL promoted cell expansion and maintained optimum length of root system, alleviating the oxidative stress caused by Ca(NO3)2. The continuous transduction of EBL signal thickened the secondary cell wall of casparian band cells, thus resisting against ion toxicity and maintaining water transport.

Effects of exogenous spermine on chlorophyll fluorescence, antioxidant system and ultrastructure of chloroplasts in Cucumis sativus L. under salt stress.

The effects of exogenous spermine (Spm) on plant growth, chlorophyll fluorescence, ultrastructure and anti-oxidative metabolism of chloroplasts were investigated in Cucumis sativus L. under NaCl stress. Salt stress significantly reduced plant growth, chlorophylls content and F(v)/F(m). These changes could be alleviated by foliar spraying with Spm. Salt stress caused an increase in malondialdehyde (MDA) content and superoxide anion [Formula: see text] generation rate in chloroplasts. Application of Spm significantly increased activities of superoxidase dismutase (SOD, EC 1.15.1.1), peroxidase (POD, EC 1.11.1.7), and ascorbate peroxidase (APX, EC 1.11.1.11) which decreased the levels of [Formula: see text] and MDA in the salt-stressed chloroplasts. Salt stress decreased the activities of dehydroascorbate reductase (DHAR, EC 1.8.5.1) and glutathione reductase (GR, EC 1.6.4.2) in the chloroplasts and reduced the contents of dehydroascorbate (DAsA) and glutathione (GSH), but increased monodehydroascorbate reductase (MDAR, EC 1.6.5.4) activity. On the other hand, Spm significantly increased the activities of antioxidant enzymes and levels of antioxidants in the salt-stressed chloroplasts. Further analysis of the ultrastructure of chloroplasts indicated that salinity induced destruction of the chloroplast envelope and increased the number of plastoglobuli with aberrations in thylakoid membranes. However, Spm application to salt-stressed plant leaves counteracted the adverse effects of salinity on the structure of the photosynthetic apparatus. These results suggest that Spm alleviates salt-induced oxidative stress through regulating antioxidant systems in chloroplasts of cucumber seedlings, which is associated with an improvement of the photochemical efficiency of PSII.

Identification of the geographic origin of Dendrobium thyrsiflorum on Chinese herbal medicine market using trinucleotide microsatellite markers.

The stems of Dendrobium thyrsiflorum RCHB.F. ex ANDRÉ can be processed into an important class of Traditional Chinese Medicine named "Huangcao Shihu," which has diverse curative effects, such as nourishing yin and clearing away unhealthy heat, benefiting the stomach, and promoting the production of body fluid. The identification of the geographical origin of D. thyrsiflorum is vital for preserving its natural resource and ensuring the quality of "Huangcao Shihu." In order to identify the origin of D. thyrsiflorum on Chinese herbal medicine market, 14 D. thyrsiflorum-specific microsatellite markers were developed in this study. Assignment tests were performed by the microsatellite marker analysis coupled with three new statistical approaches (partially Bayesian, frequency-based, and fully Bayesian methods) to determine the origin populations of 12 commercial samples of "Huangcao Shihu" collected from a medicine market in Nanjing, Jiangsu Province, China. Their genotypes were compared with those of 136 individuals belonging to five wild D. thyrsiflorum populations from China, Thailand, India, Myanmar, and Laos. Comparisons of the probabilities of 12 unknown individuals originating from each candidate population indicated that most of them appeared to originate from Myanmar and Laos. This suggests that the two countries may be the predominant sources of D. thyrsiflorum on the medicine market in Nanjing. In addition, the 14 microsatellite markers developed in this study may be an effective tool for identification of the origin of commercial available "Huangcao Shihu" and play an important role in its quality control.

[Evaluation of genetic diversity of Dendrobium officinale wild populations based on RAMP markers].

Random amplified microsatellite polymorphism (RAMP) markers were used to access the genetic diversity among 112 samples of nine populations of Dendrobium officinale Kimura et Migo. Using 16 informative primers, 123 bands were amplified and 86 (69.92%) were polymorphic. The polymorphic bands from three to eight could be detected for each RAMP primer, with a mean of 5, indicating abundant genetic diversity among populations. Genetic similarity coefficients ranged from 0.250 to 0.813. UPGMA dendrogram illustrated 9 populations clustered into 3 groups, and the cluster pattern showed correlation with the locations of the D. officinale populations. These results were supported by the previous conclusions that were achieved by other molecular markers, and RAMP is proved to be effective for evaluating the genetic diversity of wild populations of Dendrobium officinale.