Discovery and development of benzene sulfonamide derivatives as anti-hepatic fibrosis agents.

A novel benzene sulfonamide compound named IMB16-4 exhibits excellent anti-hepatic fibrosis activity in a recent study. To develop potential anti-hepatic fibrosis agents, a series of benzene sulfonamide derivatives were designed and synthesized based on the scaffold of the lead compound IMB16-4. As it turned out, most of the derivatives displayed potential anti-hepatic fibrosis activity, among which, compounds 11a, 11b, 11d, 13a, 36b, and 47b exhibited inhibition rates of 42.3%, 48.7%, 42.4%, 40.0%, 39.4%, and 49.3%, respectively, which were equivalent to the control IMB16-4 with an inhibition rate of 35.9%, Costunolide with an inhibition rate of 45.4%, and much more potent than that of Epigallocatechin gallate (EGCG) with an inhibition rate of 25.3%. Especially, compounds 46a, 46b, and 46c exhibited excellent anti-hepatic fibrosis activity with inhibition rates of 61.7%, 54.8%, and 60.7%, which were almost 1.5-fold inhibition rates of IMB16-4. In addition, compounds 46a, 46b, and 46c exhibited remarkable inhibitory activity in the gene expression of COL1A1, MMP-2, and the protein expression of COL1A1, FN, α-SMA, and TIMP-1 by inhibiting the JAK1-STAT1/3 pathway. These findings furnished valuable inspiration for the further development of anti-hepatic fibrosis agents.

Design and Evaluation of Novel HIV-1 Protease Inhibitors Containing Phenols or Polyphenols as P2 Ligands with High Activity against DRV-Resistant HIV-1 Variants.

With the increasing prevalence of drug-resistant variants, novel potent HIV-1 protease inhibitors with broad-spectrum antiviral activity against multidrug-resistant causative viruses are urgently needed. Herein, we designed and synthesized a new series of HIV-1 protease inhibitors with phenols or polyphenols as the P2 ligands and a variety of sulfonamide analogs as the P2' ligands. A number of these new inhibitors showed superb enzymatic inhibitory activity and antiviral activity. In particular, inhibitors 15d and 15f exhibited potent enzymatic inhibitory activity in the low picomolar range, and the latter showed excellent activity against the Darunavir-resistant HIV-1 variant. Furthermore, the molecular modeling studies provided insight into the ligand-binding site interactions between inhibitors and the enzyme cavity, and they sparked inspiration for the further optimization of potent inhibitors.

Rational Design and Systemic Appraisal of an EGFR-Targeting Antibody-Drug Conjugate LR-DM1 for Pancreatic Cancer.

By harnessing the payload DM1 and a monoclonal antibody LR004 through a noncleavable linker succinimidyl-4-(N-maleimidomethyl)-cyclohexane-1-carboxylate, we designed and evaluated an antibody-drug conjugate LR-DM1 with an appropriate drug-antibody ratio of 3.6. LR-DM1, which was targeted toward the epidermal growth factor receptor for pancreatic cancer, exhibited potent antiproliferation activity in vitro with a half-maximal inhibitory concentration value of 7.03 nM for Capan-2 cells. Particularly, it displayed prominent tumor growth inhibition in vivo under 20 mg/kg LR-DM1 dosage in a single administration or multiple administrations without apparent abnormality of pathological observation. Moreover, LR-DM1 possessed a relatively broad therapeutic index with a half-lethal dose above 300 mg/kg, which was over 15-fold higher than the highest administration dosage of 20 mg/kg. This initial study on LR-DM1 holds promise for further development of a new antibody drug conjugate that is transformative for treatment of patients concerned.

Discovery of 1,8-naphthalidine derivatives as potent anti-hepatic fibrosis agents via repressing PI3K/AKT/Smad and JAK2/STAT3 pathways.

Liver fibrosis is one of the most common pathological consequences of chronic liver diseases (CLD). To develop effective antifibrotic strategies, a novel class of 1-(substituted phenyl)-1,8-naphthalidine-3-carboxamide derivatives were designed and synthesized. By means of the collagen type I α 1 (COL1A1)-based screening and cytotoxicity assay in human hepatic stellate cell (HSC) line LX-2, seven compounds were screened out from total 60 derivatives with high inhibitory effect and relatively low cytotoxicity for further COL1A1 mRNA expression analysis. It was found that compound 17f and 19g dose-dependently inhibited the expression of fibrogenic markers, including α-smooth muscle actin (α-SMA), matrix metalloprotein 2 (MMP-2), connective tissue growth factor (CTGF) and transforming growth factor ß1 (TGFß1) on both mRNA and protein levels. Further mechanism studies indicated that they might suppress the hepatic fibrogenesis via inhibiting both PI3K/AKT/Smad and non-Smad JAK2/STAT3 signaling pathways. Furthermore, 19g administration attenuated hepatic histopathological injury and collagen accumulation, and reduced fibrogenesis-associated protein expression in liver tissues of bile duct ligation (BDL) rats, showing significant antifibrotic effect in vivo. These findings identified 1,8-naphthalidine derivatives as potent anti-hepatic fibrosis agents, and provided valuable information for further structure optimization.

Discovery and optimization of 2-((1H-indol-3-yl)thio)-N-benzyl-acetamides as novel SARS-CoV-2 RdRp inhibitors.

The emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the global pandemic coronavirus disease (COVID-19), but no specific antiviral drug has been proven effective for controlling this pandemic to date. In this study, several 2-((indol-3-yl)thio)-N-benzyl-acetamides were identified as SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) inhibitors. After a two-round optimization, a new series of 2-((indol-3-yl)thio)-N-benzyl-acetamides was designed, synthesized, and evaluated for SARS-CoV-2 RdRp inhibitory effect. Compounds 6b2, 6b5, 6c9, 6d2, and 6d5 were identified as potent inhibitors with IC50 values of 3.35 ± 0.21 µM, 4.55 ± 0.2 µM, 1.65 ± 0.05 µM, 3.76 ± 0.79 µM, and 1.11 ± 0.05 µM, respectively; the IC50 of remdesivir (control) was measured as 1.19 ± 0.36 µM. All of the compounds inhibited RNA synthesis by SARS-CoV-2 RdRp. The most potent compound 6d5, which showed a stronger inhibitory activity against the human coronavirus HCoV-OC43 than remdesivir, is a promising candidate for further investigation.

Design and biological evaluation of novel HIV-1 protease inhibitors with isopropanol as P1' ligand to enhance binding with S1' subsite.

Newly designed HIV-1 protease inhibitors that maximize interactions with the protein backbone, especially in the form of hydrogen bonds, may enhance the antiviral potency of these compounds and minimize acquisition of drug-resistant mutations. Herein, we described a series of new HIV-1 PIs containing phenols as the P2 ligands and chiral isopropanol as the P1' ligands, in combination with 4-trifluoromethylphenylsulfonamide or 4-nitrophenylsulfonamide as the P2' ligands. And most of these compounds exhibited nanomolar inhibitory potency. In particular, inhibitors 13c and 13e with 4-trifluoromethylphenylsulfonamide as the P2' ligand and (R) - isopropanol as the P1' ligand, exhibited antiviral IC50 values of 1.64 nM and 2.33 nM, respectively. Furthermore, they also showed remarkable activity against wild-type and DRV-resistant HIV-1 variants that raised the prospect of designing more effective PIs further.

Synthesis and evaluation of potent human immunodeficiency virus 1 protease inhibitors with epimeric isopropanol as novel P1' ligands.

Aim: HIV-1 protease inhibitors regimens suffered from a number of drawbacks, among which, the most egregious issue was the growing emergence of drug-resistant strains. Materials & methods: The design strategy of maximizing the protease active site interactions with the inhibitor, especially promoting extensive hydrogen bonding with the protein backbone atoms, might be in favor of combating drug resistance. A series of HIV-1 protease inhibitors that incorporated enantiomeric isopropanols as the P1' ligands in combination with phenols as the P2 ligands were reported herein. Results: A number of inhibitors displayed potent protease enzyme inhibition activity. In particular, inhibitor 14c showed comparable potency as darunavir with IC50 value of 1.91 nM and activity against darunavir-resistant HIV-1 variants. Conclusion: The new kind of HIV-1 protease inhibitors deserves further study.

Design and synthesis of 2-((1H-indol-3-yl)thio)-N-phenyl-acetamides as novel dual inhibitors of respiratory syncytial virus and influenza virus A.

Respiratory syncytial virus (RSV) and influenza A virus (IAV) are two of the most common viruses that cause substantial morbidity and mortality in infants, young children, elderly persons, and immunocompromised individuals worldwide. Currently, there are no licensed vaccines or selective antiviral drugs against RSV infections and most IAV strains become resistant to clinical anti-influenza drug. Here, we described the discovery of a series of 2-((1H-indol-3-yl)thio)-N-phenyl-acetamide as novel and potent RSV and IAV dual inhibitors. Thirty-five derivatives were designed, prepared, and evaluated for their anti-RSV and anti-IAV activities. Among the tested compounds, 14'c, 14'e, 14'f, 14'h, and 14'i exhibited excellent activity against both RSV and IAV, which showed low micromolar to sub-micromolar EC50 values. Further, compounds 14'c and 14'e were identified as the most promising dual inhibitors with lesser cytotoxicity than the clinical drug, ribavirin. These findings may contribute to the development of a lead compound for the treatment of RSV and/or IAV infections.

Design, Synthesis, and Cytotoxic Activity of 3-Aryl-N-hydroxy-2-(sulfonamido)propanamides in HepG2, HT-1080, KB, and MCF-7 Cells.

A new series of (sulfonamido)propanamides (6a1-6a13, 6b1-6b15, 7c1-7c5, 6d1-6d5, 6e1-6e6) was designed and synthesized. All the synthesized compounds were characterized by NMR and mass spectrometry. The target compounds were evaluated for their in vitro cytotoxic activity against hepatocellular carcinoma (HepG2), fibrosarcoma (HT-1080), mouth epidermal carcinoma (KB), and breast adenocarcinoma (MCF-7) cell lines with the sulforhodamine B (SRB) assay, with gemcitabine and mitomycin C as positive controls. Most of these compounds exhibit a more potent cytotoxic effect than the positive control group on various cancer cell lines and the most potent compound, 6a7, shows the IC50 values of 29.78±0.516 µm, 30.70±0.61 µm, and 64.89±3.09 µm in HepG2, HT-1080, KB, and MCF-7 cell lines, respectively. Thus, these compounds with potent cytotoxic activity have potential for development as new chemotherapy agents.

A novel ASBT inhibitor, IMB17-15, repressed nonalcoholic fatty liver disease development in high-fat diet-fed Syrian golden hamsters.

The manipulation of bile acid (BA) homeostasis by blocking the ileal apical Na+-dependent bile salt transporter (ASBT/SLC10A2) may have therapeutic effects in nonalcoholic fatty liver disease. We developed a novel ASBT inhibitor, an N-(3,4-o-dichlorophenyl)-2-(3-trifluoromethoxy) benzamide derivative referred to as IMB17-15, and investigated its therapeutic effects and the molecular mechanisms underlying the effects. Syrian golden hamsters were challenged with high-fat diet (HFD) to induce NAFLD and were subsequently administered 400 mg/kg IMB17-15 by gavage daily for 21 days. Serum, liver, and fecal samples were collected for further analysis. Plasma concentration-time profiles of IMB17-15 were also constructed. The human hepatocyte cell line HL-7702 was treated with Oleic acid (OA) with or without IMB17-15. Western blotting and real-time PCR were used to study the molecular mechanisms of IMB17-15. We found that IMB17-15 inhibited ASBT and subsequently suppressed ileal farnesoid X receptor (FXR) and FXR-activated fibroblast growth factor15/19 (FGF15/19) expression, which reduced the hepatic phosphorylated extracellular regulated protein kinase (ERK) and c-Jun N-terminal kinase (JNK) levels and upregulated the cholesterol 7α-hydroxylase (CYP7A1) activity. Additionally, IMB17-15 stimulated adenosine monophosphate (AMP)-activated protein kinase (AMPKα) phosphorylation and enhanced peroxisome proliferator activated receptor α (PPARα) expression and thus promoted triglyceride (TG) oxidation and high-density lipoprotein cholesterol (HDL-c) metabolism through an ASBT-independent mechanism. In conclusion, a novel ASBT inhibitor known as IMB17-15 protected hamsters against HFD-induced NFALD by manipulating BA and lipid homeostasis. IMB17-15 also reduced lipid deposition in human hepatic cell lines, indicating that it may be useful as a therapy for NAFLD patients.

A novel protein kinase inhibitor IMB-YH-8 with anti-tuberculosis activity.

Protein kinase B (PknB) is one of the Mycobacterium tuberculosis serine/threonine protein kinases and has an essential role in sustaining mycobacterial growth. Here, we identified and characterized a novel small molecule compound named IMB-YH-8 that inhibited PknB and served as anti-mycobacteria lead compound. IMB-YH-8 inhibited PknB auto-phosphorylation and the phosphorylation of GarA by PknB in a dose-dependent manner. The compound did not inhibit human Akt1 or other serine/threonine kinases in M. tuberculosis except for the highly homologous PknA. IMB-YH-8 bound to PknB with a moderate affinity. Molecular docking revealed that IMB-YH-8 interacts with the catalytic domain of PknB. Observations of electron microscopy showed that IMB-YH-8 changed the morphology of H37Rv and disrupted the cell wall. The differential transcriptional response of M. tuberculosis to IMB-YH-8 revealed changes in SigH regulatory pathways modulated by PknB. Notably IMB-YH-8 not only potently inhibited drug-sensitive and multidrug-resistant clinical isolates but also exhibited a dose dependent inhibition of intracellular M. tuberculosis. Taken together, these in vitro data demonstrate that IMB-YH-8 is a novel inhibitor of PknB, which potently prevents growth of M. tuberculosis. It is as yet unclear whether inhibition of PknA contributes to the anti-tubercular action of IMB-YH-8.

[Advances in studies of ileal apical sodium-dependent bile acid transporter].

Bile acids play critical roles in the regulation of metabolism and absorption of lipids. The ileal apical sodium-dependent bile acid transporter (ASBT) located at the enterocyte brush border is responsible for the reuptake of bile acids and the maintenance of bile acid homeostasis. Recently, a number of investigations have been made concerning the regulation and control of ASBT and the relationship between ASBT and intestinal inflammation, tumorigenesis, diabetes mellitus and hyperlipemia, which suggests ASBT as a potential therapeutic target of these diseases. In this review, advances in the study of above-mentioned issues were summarized.

Preliminary SAR and biological evaluation of antitubercular triazolothiadiazine derivatives against drug-susceptible and drug-resistant Mtb strains.

Following up the SAR study of triazolothiadiazoles for their antitubercular activities targeting Mt SD in our previous study, on the principle of scaffold hopping, the C3 and C6 positions of triazolothiadiazine were examined systematically to define a preliminary structure-activity relationship (SAR) with respect to biological activity. This study herein highlights the potential of two highly potent advanced leads 6c-3, 6g-3 and several other compounds with comparable potencies as promising new candidates for the treatment of TB (6c-3, MIC-H37Rv=0.25µg/mL; MIC-MDRTB=2.0µg/mL; MIC-RDRTB=0.25µg/mL; Mt SD-IC50=86.39µg/mL; and 6g-3, MIC-H37Rv=1.0µg/mL; MIC-MDRTB=4.0µg/mL; MIC-RDRTB=2.0µg/mL; Mt SD-IC50=73.57µg/mL). Compounds 6c-3 and 6g-3 possessed a para-nitro phenyl at the 6 position showed low Vero and HepG2 cells toxicity, turning out to be two excellent lead candidates for preclinical trials. In addition, in vitro Mt SD inhibitory assay indicates that Mt SD is at least one of the targets for their antitubercular activity. Thus, they may turn out to be promising multidrug-resistance-reversing agents.

Herbihabitans rhizosphaerae gen. nov., sp. nov., a member of the family Pseudonocardiaceae isolated from rhizosphere soil of the herb Limonium sinense (Girard).

The taxonomic position of an actinobacterium, designated CPCC 204279T, which was isolated from a rhizosphere soil sample of the herb Limonium sinense collected from Xinjiang Province, China, was established using a polyphasic approach. Whole-cell hydrolysates of strain CPCC 204279T contained galactose and arabinose as diagnostic sugars and meso-diaminopimelic acid as the diamino acid. The muramic acid residues in the peptidoglycan were N-acetylated. The predominant menaquinone was MK-9(H4). The phospholipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides. The major fatty acids were iso-C16 : 0, iso-C16 : 0 2-OH, C16 : 1ω9c, iso-C16 : 1 and C16 : 0. The genomic DNA G+C content was 73.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CPCC 204279T should be placed in the family Pseudonocardiaceae, in which the strain formed a distinct lineage next to the genus Actinophytocola. Signature nucleotides in the 16S rRNA gene sequence showed that the strain contained the Pseudonocardiaceae family-specific 16S rRNA signature nucleotides and a genus-specific diagnostic nucleotide signature pattern. The combination of phylogenetic analysis and phenotypic characteristics supported the conclusion that strain CPCC 204279T represents a novel species of a new genus in the family Pseudonocardiaceae, for which the name Herbihabitans rhizosphaerae gen. nov., sp. nov. is proposed. Strain CPCC 204279T (=NBRC 111774T=DSM 101727T) is the type strain of the type species.

Synthesis and antitumor activity of ATB-429 derivatives containing a nitric oxide-releasing moiety.

A series of novel ATB-429 (an anti-inflammatory candidate) derivatives containing a nitric oxide (NO)-releasing moiety were designed, synthesized and evaluated for their in vitro activity against six human cancer cell lines. Our results reveal that phenylsulfonylfuroxan-based derivatives have considerable antitumor activity, and compounds 7-9 (IC50s: 0.256-3.024 µM) against HT-29 and PANC-1, 8a,b (IC50s: 2.677-3.051 µM) against MCF-7 and 8a (IC50: 1.270 µM) against DU145 are more active than Vandetanib (IC50s: 1.925-4.107 µM).

Synthesis and cytotoxic evaluation of alkoxylated chalcones.

A series of chalcones a1-20 bearing a 4-OMe groups on the A-ring were initially synthesized and their anticancer activities towards HepG2 cells evaluated. Subsequently, a series of chalcones b1-42 bearing methoxy groups at the 2' and 6'-positions of the B-ring were synthesized and their anticancer activities towards five human cancer cell lines (HepG2, HeLa, MCF-7, A549 and SW1990) and two non-tumoral human cell lines evaluated. The results showed that six compounds (b6, b8, b11, b16, b18, b22, b23 and b29) displayed promising activities, with compounds b22 and b29 in particular showing higher levels of activity than etoposide against all five cancer cell lines. Compound b29 showed a promising SI value compared with both HMLE and L02 (2.1-6.5 fold in HMLE and > 33 > 103.1 fold in L02, respectively).

tert-Butyl N-[2-(N-isobutyl-4-meth-oxy-benzene-sulfonamido)-eth-yl]carbamate.

The title compound, C18H30N2O5S, was synthesized by the reaction of tert-butyl 2-(iso-butyl-amino)-ethyl-carbamate with p-meth-oxy-phenyl-sulfonyl chloride. In the mol-ecule, two intra-molecular C-H⋯O hydrogen bonds are observed. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds involving the imino group N atom and the ester group O atom into chains running parallel to the b axis. The chains are further connected by C-H⋯O hydrogen bonds, forming layers parallel to the bc plane.

Design, synthesis and anticancer activity of 1-acyl-3-amino-1,4,5,6-tetrahydropyrrolo[3,4-c]pyrazole derivatives.

A series of novel 1-acyl-3-amino-1,4,5,6-tetrahydropyrrolo[3,4-c]pyrazole derivatives were designed and synthesized. These derivatives were initially evaluated for their in vitro anticancer activity against human colon carcinoma HCT-116 cell line, and compounds 11a, b were chosen for further evaluation their in vitro activity against other five human cancer cell lines. These results indicate that most of the target compounds have considerable in vitro anticancer activity. The most active compound 11a was found to be 4- to 28-fold more potent than (R)-roscovitine against six human cancer cell lines. In addition, compound 11a was assessed for its activity against 12 kinases, and then evaluated for its interaction mode by docking experiments with cyclin-dependent kinase 5 (CDK5) and glycogen synthase kinase-3ß (GSK3ß).

Pharmacophore-based virtual screening and biological evaluation of small molecule inhibitors for protein arginine methylation.

Protein arginine methyltransferases (PRMTs) are proved to play vital roles in chromatin remodeling, RNA metabolism, and signal transduction. Aberrant regulation of PRMT activity is associated with various pathological states such as cancer and cardiovascular disorders. Development and application of small molecule PRMT inhibitors will provide new avenues for therapeutic discovery. The combination of pharmacophore-based virtual screening methods with radioactive methylation assays provided six hits identified as inhibitors against the predominant arginine methyltransferase PRMT1 within micromolar potency. Two potent compounds, A9 and A36, exhibited the inhibitory effect by directly targeting substrate H4 other than PRMT1 and displayed even higher inhibition activity than the well-known PRMT inhibitors AMI-1. A9 significantly inhibits proliferation of castrate-resistant prostate cancer cells. Together, A9 may be a potential inhibitor against advanced hormone-independent cancers, and the work will provide clues for the future development of specific compounds that block the interaction of PRMTs with their targets.

Regioselective synthesis and in vitro anticancer activity of 4-aza-podophyllotoxin derivatives catalyzed by L-proline.

A series of 4-aza-podophyllotoxin derivatives have been synthesized regioselectively via the three-component reaction of aldehydes, aromatic amines, and tetronic acid catalyzed by l-proline. This method has the advantages of high yield, high regioselectivity, extensive adaptability, easy operation, and environmental friendliness. These compounds were also investigated in vitro, and some were found to have good anticancer activity.