Multidimensional virtual screening approaches combined with drug repurposing to identify potential covalent inhibitors of SARS-CoV-2 3CL protease.

The outbreak of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused an unprecedented global pandemic, and new cases are still on the rise due to the absence of effective medicines. However, developing new drugs within a short time is extremely difficult. Repurposing the existing drugs provides a fast and effective strategy to identify promising inhibitors.

Synthesis and bioactivity evaluation of pachymic acid derivatives as potential cytotoxic agents.

Pachymic acid, a well-known natural lanostane-type triterpenoid, exhibits various pharmacological properties. In this study, 18 derivatives of pachymic acid were synthesized by modifying their molecular structures and evaluated for their anticancer activity against two human cancer cell lines using the CCK-8 assay. Structure-activity relationship studies according to the in vitro cytotoxicity unexpectedly found one promising derivative (namely tumulosic acid, also found in ), which had stronger anti-proliferative activity than the positive drug cisplatin against HepG2 and HSC-2 cell lines with IC values of 7.

Pharmacological profiles and therapeutic applications of pachymic acid (Review).

is a saprophytic fungus that grows in diverse species of . Its sclerotium, called fu-ling or hoelen, has been used in various traditional Chinese medicines and health foods for thousands of years, and in several modern proprietary traditional Chinese medicinal products. It has extensive clinical indications, including sedative, diuretic, and tonic effects.

Anticancer potential of indirubins in medicinal chemistry: Biological activity, structural modification, and structure-activity relationship.

Indirubin is the crucial ingredient of Danggui Longhui Wan and Qing-Dai, traditional Chinese medicine herbal formulas used for the therapy of chronic myelocytic leukemia in China for hundreds of years. Although the monomeric indirubin has been used in China for the treatment human chronic myelocytic leukemia. However, due to low water solubility, poor pharmacokinetic properties and low therapeutic effects are the major obstacle, and had significantly limited its clinical application.

Mechanistic Exploration of Methionine 274 Acting as a "Switch" of the Selective Pocket Involved in HDAC8 Inhibition: An in Silico Study.

The overexpression of histone deacetylase 8 (HDAC8) causes several diseases, and the selective inhibition of HDAC8 has been touted as a promising therapeutic strategy due to its fewer side effects. However, the mechanism of HDAC8 selective inhibition remains unclear. In this study, flexible docking and in silico mutation were used to explore the structural change of methionine (M274) during HDAC8 binding to inhibitors, along with the reason for this change.

SARs of a novel series of s-triazine compounds targeting vimentin to induce methuotic phenotype.

Herein, we describe the design, synthesis and structure-activity relationships of a series of novel s-triazine compounds can induce methuotic phenotype in various types of cancer cells. (E)-1-(4-Chlorophenyl)-3-(4-((4-morpholino-6-styryl-1,3,5-triazine-2-yl)amino)phenyl)urea, compound V6, exhibited a striking methuotic phenotype with a minimal effective concentration of less than 10 nM in U87 glioblastoma cells. Based on structure-activity relationship studies, we designed and synthesized an active probe P1 that retained the full potential of V6 in inducing the methuotic phenotype in U87 glioblastoma cells.

Screening for the selective inhibitors of MMP-9 from natural products based on pharmacophore modeling and molecular docking in combination with bioassay experiment, hybrid QM/MM calculation, and MD simulation.

Matrix metalloproteinase-9 (MMP-9) has been considered as an attractive target involving cancer therapy. In this study, the 3D QSAR pharmacophore model of MMP-9 inhibitors is built, and its reliability is subsequently validated based on different methods. The built pharmacophore model consists of the four chemical features, including two hydrogen bond acceptors (HBA), one hydrophobic (HY), and one ring aromatic (RA).

Hierarchical virtual screening of the dual MMP-2/HDAC-6 inhibitors from natural products based on pharmacophore models and molecular docking.

The dual-target inhibitors tend to improve the response rate in treating tumors, comparing with the single-target inhibitors. Matrix metalloproteinase-2 (MMP-2) and histone deacetylase-6 (HDAC-6) are attractive targets for cancer therapy. In this study, the hierarchical virtual screening of dual MMP-2/HDAC-6 inhibitors from natural products is investigated.

Synthesis and biological evaluation of novel 2-arylvinyl-substituted naphtho[2,3-d]imidazolium halide derivatives as potent antitumor agents.

Two series of novel 2-arylvinyl-naphtho[2,3-d]imidazol-3-ium iodide derivatives and 2-arylvinyl-naphtho[2,3-d]imidazol-3-ium bromide derivatives were designed and synthesized by the structural combination of YM155 with stilbenoids. All compounds were tested for anti-proliferative activity against PC-3, A375 and HeLa human cancer cell lines. Two of the compounds were selected for further investigation: 12b, which showed potent cytotoxicity against the three tested cell lines with IC values in the range of 0.

Glioma and microenvironment dual targeted nanocarrier for improved antiglioblastoma efficacy.

Drug delivery systems based on nanoparticles (nano-DDS) have aroused attentions for the treatment of glioblastoma (GBM), the most malignant brain cancer with a dismal prognosis. However, there are still numerous unmet challenges for traditional nano-DDS, such as the poor nanoparticle penetration, short retention in the GBM parenchyma and low glioma targeting ability. Herein, we used Pep-1 and CREKA peptides to construct a novel multifunctional GBM targeting nano-DDS (PC-NP).

A Novel Synthesis of the Efficient Anti-Coccidial Drug Halofuginone Hydrobromide.

: Halofuginone hydrobromide () is recognized as an effective drug against several species of (E.) in poultry. In this paper, we describe a convenient and low cost preparation method for the compound, as well as primary validation of its activity.

Facile access to 2,2-disubstituted indolin-3-ones via a cascade Fischer indolization/Claisen rearrangement reaction.

An efficient approach for the synthesis of 2,2-disubstituted indolin-3-ones is described. From readily accessible aryl hydrazines and allyloxyketones, 2,2-disubstituted indolin-3-ones could be obtained in good to excellent yields under mild reaction conditions via a cascade Fischer indolization/Claisen rearrangement process. This protocol provides a facile entry to 2,2-disubstituted indolin-3-ones, which have been applied in the construction of the benzofuroindoline framework related to Phalarine.

Multiple receptor-ligand based pharmacophore modeling and molecular docking to screen the selective inhibitors of matrix metalloproteinase-9 from natural products.

Matrix metalloproteinase-9 (MMP-9) is an attractive target for cancer therapy. In this study, the pharmacophore model of MMP-9 inhibitors is built based on the experimental binding structures of multiple receptor-ligand complexes. It is found that the pharmacophore model consists of six chemical features, including two hydrogen bond acceptors, one hydrogen bond donor, one ring aromatic regions, and two hydrophobic (HY) features.

Ru(II)-Catalyzed Direct C(sp(2))-H Activation/Selenylation of Arenes with Selenyl Chlorides.

A new ruthenium catalytic system was developed for the construction of a C(sp(2))-Se bond with the assistance of directing groups. This protocol features mild reaction conditions, wider substrate scope, and convenient late-stage selenylation of bioactive molecules.

Scaffold Hopping Approach to a New Series of Pyridine Derivatives as Potent Inhibitors of CDK2.

A scaffold hopping approach was exploited to guide the discovery of a series of pyridine derivatives as novel cyclin-dependent kinase (CDK2) inhibitors. These new compounds were designed, synthesized, and evaluated as CDK2 inhibitors. Most of the compounds showed potent inhibition against CDK2, and preliminary structure-activity relationship trends were revealed.

Enantioselective Bromo-oxycyclization of Silanol.

Relying on the nucleophilicity of silanol for building up silicon-incorporated scaffold with an enantiopure tetrasubstituted carbon center remains elusive. In this report, asymmetric bromo-oxycyclization of olefinic silanol by using chiral anionic phase-transfer catalyst is described. This protocol provided a facile entry to a wide arrangement of enantiopure benzoxasilole in moderate to excellent enantioselectivities depending on the unique reactivity of bromine/N-benzyl-DABCO complex.

An Effective Synthesis Method for Tilorone Dihydrochloride with Obvious IFN-α Inducing Activity.

Tilorone dihydrochloride (1) has great potential for inducing interferon against pathogenic infection. In this paper, we describe a convenient preparation method for 2,7-dihydroxyfluoren-9-one (2), which is a usual pharmaceutical intermediate for preparing tilorone dihydrochloride (1). In the novel method, methyl esterification of 4,4'-dihydroxy-[1,1'-biphenyl]-2-carboxylic acid (4) was carried out under milder conditions with higher yield and played an important role in the preparation of compound 2.

Novel tetracyclic benzo[b]carbazolones as highly potent and orally bioavailable ALK inhibitors: design, synthesis, and structure-activity relationship study.

Four series of tetracyclic benzo[b]carbazolone compounds possessing more rotatable bonds and higher molecular flexibility were designed by either inserting a linker within the C8-side chain or by opening the middle ketone ring on the basis of compound 5 (Alectinib, CH5424802). Compound 15b was identified showing nearly identical high potency against both wild-type and the gatekeeper mutant ALK kinase (3.4 vs 3.

N-(1-Oxy-2-picolyl)oxalamic acids as a new type of O,O-ligands for the Cu-catalyzed N-arylation of azoles with aryl halides in water or organic solvent.

N-(1-Oxy-pyridin-2-ylmethyl)oxalamic acids (L3-L5) were identified as novel efficient ligands for copper-catalyzed C-N cross-coupling of azoles and aryl halides in water. The N-arylation of imidazoles, indoles and pyrazoles proceeded with moderate to excellent yields and complete selectivity over aromatic amines and phenols. Moreover, L5, which is also efficient in organic solvent with low catalyst loading, can be used to promote the N-arylation reactions with water-sensitive materials.

Discovery and SAR study of c-Met kinase inhibitors bearing an 3-amino-benzo[d]isoxazole or 3-aminoindazole scaffold.

A series of 3-amino-benzo[d]isoxazole-/3-aminoindazole-based compounds were designed, synthesized and pharmacologically evaluated as tyrosine kinase c-Met inhibitors. The SAR study was conducted leading to identification of nine compounds (8d, 8e, 12, 28a-d, 28h and 28i) with IC50s less than 10nM against c-Met. Compound 28a stood out as the most potent c-Met inhibitor displaying potent inhibitory effects both at enzymatic (IC50=1.

Synthesis and quantitative structure-activity relationship (QSAR) analysis of some novel oxadiazolo[3,4-d]pyrimidine nucleosides derivatives as antiviral agents.

We have synthesized a series of 4H,6H-[1,2,5]oxadiazolo[3,4-d]pyrimidine-5,7-dione 1-oxide nucleoside and their anti-vesicular stomatitis virus (VSV) activities in Wish cell were also investigated in vitro. It was found that most compounds showed obvious anti-VSV activities and compound 9 with ribofuranoside improved the anti-VSV activity by approximately 10 times and 18 times compared to didanosine (DDI) and acyclovir, respectively. A quantitative structure-activity relationship (QSAR) study of these compounds as well as previous reported oxadiazolo[3,4-d]pyrimidine nucleoside derivatives indicated that compounds with high activity should have small values of logP(o/w), vsurf_G and a large logS value.

Novel 2,4-Diarylaminopyrimidine Analogues (DAAPalogues) Showing Potent c-Met/ALK Multikinase Inhibitory Activities.

By repurposing a typical dopamine D1/D5 receptor agonist motif, C1-substituted-N3-benzazepine or benzazecine, into the classical RTK inhibitor 2,4-diaminopyrimidine skeleton, a series of new 2,4-diarylaminopyrimidine analogues (DAAPalogues) were developed. Compounds 7 and 8a were identified possessing high potency against both c-Met and ALK kinases. Compound 8a displayed appreciable antitumor efficacy at the dose of 1 mg/kg in the ALK-driven BF3/EML4-ALK xenograft mice model.

Palladium-catalyzed double C-H activation: one-pot synthesis of benzo[c]pyrazolo[1,2-a]cinnolin-1-ones from 5-pyrazolones and aryl iodides.

A palladium-catalyzed dual C-H activation to construct C-C/C-N bonds for one-pot synthesis of benzo[c]pyrazolo[1,2-a]cinnolin-1-ones is successfully developed. This approach involves using a pyrazolone moiety as an internal directing group for C-H activation, and provides a flexible strategy to access this polycyclic skeleton.

Rh(III)-catalyzed intermolecular C-H amination of 1-aryl-1H-pyrazol-5(4H)-ones with alkylamines.

An intermolecular C-H amination of 1-aryl-1H-pyrazol-5(4H)-ones was achieved under mild reaction conditions, using a low catalyst loading and with a broad scope of aminating reagents. This protocol not only provides the first example of rhodium(III)-catalyzed intermolecular aromatic C-H amination directed by an intrinsic functionality of the substrate/product but also features aminating an existing drug with either primary or secondary N-benzoate alkylamines as the coupling partners.

Synthesis, in vitro and in vivo antitumor activity of symmetrical bis-Schiff base derivatives of isatin.

Eighteen symmetrical bis-Schiff base derivatives of isatin were synthesized by condensation of the natural or synthetic isatins with hydrazine and were evaluated for their in vitro and in vivo antitumor activities. More than half of the obtained compounds showed potent cytotoxicity according to the MTT assay on five different human cancer cell lines (i.e.