Novel 1,2,3-Triazole-Based Benzothiazole Derivatives: Efficient Synthesis, DFT, Molecular Docking, and ADMET Studies

Highly potent anti-melanogenic effect of 2-thiobenzothiazole derivatives through nanomolar tyrosinase activity inhibition

Compounds with sulfhydryl substituents and azole compounds exhibit potent anti-tyrosinase potency. 2-Thiobenzothiazole (2-TBT), a hybrid structure of sulfhydryl and azole, exists in two tautomeric forms, with the thione form being predominant according to several studies. 2-TBT derivatives were synthesized as potential tyrosinase inhibitors as the thione tautomeric form has the same N-CS moiety as phenylthiourea (PTU), which is suitable for chelation with the copper ions present in the tyrosinase active site. Eight of the ten 2-TBT derivatives inhibited the monophenolase and diphenolase activities of mushroom tyrosinase, with IC50 values of 0.02-0.83 μM. Kinetic studies and molecular dynamics simulations were performed to determine their mode of action and confirm that the 2-TBT derivatives bind to the tyrosinase active site with high stability. Derivatives 3, 4, 8, and 10 strongly inhibited melanogenesis in B16F10 cells in a pattern similar to the results of cellular tyrosinase inhibition, thereby suggesting that their ability to inhibit melanogenesis was due to their tyrosinase inhibitory activity. In a depigmentation experiment using zebrafish embryos, all 2-TBT derivatives showed better potency than kojic acid, even at 400 to 2000 times lower concentration, and 1 and 10 reduced zebrafish larva pigmentation more strongly than PTU even at 20 times lower concentration. Experiments investigating the changes in tyrosinase inhibitory activity of 2-TBT derivatives in the presence and absence of CuSO4 and their copper chelating ability supported that these derivatives exert their anti-melanogenic effect by chelating the copper ions of tyrosinase. These results suggest that 2-TBT derivatives are promising candidates for the treatment of hyperpigmentation-related disorders.

De novo antioxidant peptide design via machine learning and DFT studies

Antioxidant peptides (AOPs) are highly valued in food and pharmaceutical industries due to their significant role in human function. This study introduces a novel approach to identifying robust AOPs using a deep generative model based on sequence representation. Through filtration with a deep-learning classification model and subsequent clustering via the Butina cluster algorithm, twelve peptides (GP1-GP12) with potential antioxidant capacity were predicted. Density functional theory (DFT) calculations guided the selection of six peptides for synthesis and biological experiments. Molecular orbital representations revealed that the HOMO for these peptides is primarily localized on the indole segment, underscoring its pivotal role in antioxidant activity. All six synthesized peptides exhibited antioxidant activity in the DPPH assay, while the hydroxyl radical test showed suboptimal results. A hemolysis assay confirmed the non-hemolytic nature of the generated peptides. Additionally, an in silico investigation explored the potential inhibitory interaction between the peptides and the Keap1 protein. Analysis revealed that ligands GP3, GP4, and GP12 induced significant structural changes in proteins, affecting their stability and flexibility. These findings highlight the capability of machine learning approaches in generating novel antioxidant peptides.

Dual effect of light and ultrasound for efficient singlet oxygen generation with novel diaxial silicon phthalocyanine sensitizer

To treat a life-threatening disease like cancer, photodynamic therapy (PDT) and sonodynamic therapy (SDT) methods were combined into sono-photodynamic therapy (SPDT) as an effective therapeutic solution. Each day, the usage of phthalocyanine sensitizers increases in the therapeutic applications as they have the ability to produce more reactive oxygen species. In this context, a new diaxially silicon phthalocyanine sensitizer, containing triazole and tert-butyl groups, was synthesized. After elucidating the structure of the complex with elemental analysis, FT-IR, UV-Vis, MALDI-TOF MS and 1 H NMR, its photophysical, photochemical and sono-photochemical properties were examined. When singlet oxygen generation capacity of the new synthesized silicon phthalocyanine complex was determined and compared among photochemical (PDT; ФΔ  = 0.59 in DMSO, 0.44 in THF, 0.47 in toluene) and sonophotochemical (SPDT; ФΔ  = 0.88 in dimethyl sulfoxide (DMSO), 0.60 in tetrahydrofuran (THF), 0.65 in toluene) methods, it can be said that the complex is a successful sono-photosensitizer that can be used as a good SPDT agent in vitro or in vivo future studies.

Arabinofuranosyl Thymine Derivatives-Potential Candidates against Cowpox Virus: A Computational Screening Study

Cowpox is caused by a DNA virus known as the cowpox virus (CPXV) belonging to the Orthopoxvirus genus in the family Poxviridae. Cowpox is a zoonotic disease with the broadest host range among the known poxviruses. The natural reservoir hosts of CPXV are wild rodents. Recently, the cases of orthopoxviral infections have been increasing worldwide, and cowpox is considered the most common orthopoxviral infection in Europe. Cowpox is often a self-limiting disease, although cidofovir or anti-vaccinia gammaglobulin can be used in severe and disseminated cases of human cowpox. In this computational study, a molecular docking analysis of thymine- and arabinofuranosyl-thymine-related structures (1-21) on two cowpox-encoded proteins was performed with respect to the cidofovir standard and a 3D ligand-based pharmacophore model was generated. Three chemical structures (PubChem IDs: 123370001, 154137224, and 90413364) were identified as potential candidates for anti-cowpox agents. Further studies combining in vitro and in silico molecular dynamics simulations to test the stability of these promising compounds could effectively improve the future design of cowpox virus inhibitors, as molecular docking studies are not sufficient to consider a ligand a potential drug.