Synthesis, Biological Evaluation, and Docking Study of Ring-Opening Amide Analogs of Matrine as Antitumor Agents.

In this article, we designed and synthesized two series of matrine analogs with ring-opening in the lactam portion of the molecule. Our in vitro cytotoxicity study showed that analog N-(3-bromophenyl)-4-[(1R,3aS,10aR,10bS)-decahydro-1H,4H-pyrido[3,2,1-ij][1,6]naphthyridin-1-yl]butanamide (B11) with a meta-bromide on the phenyl ring displayed the best antiproliferative activity. Moreover, B11 induced cell cycle arrest in G1 phase and cell apoptosis in a dose-dependent manner in A549 cells. Molecular modeling revealed that B11 achieved a higher docking score compared to its precursor tert-butyl (1R,3aS,10aR,10bS)-1-[4-(3-bromoanilino)-4-oxobutyl]octahydro-1H,4H-pyrido[3,2,1-ij][1,6]naphthyridine-2(3H)-carboxylate (A11, an analog of B11 with a Boc group) and parent compound matrine, possibly because B11 formed a hydrogen bond with SER91 and a halogen bond with GLN320 on the binding site of annexin A2. Overall, we discovered the potential anticancer lead compound B11, which can be used for further study both in vitro and in vivo.

Pyrazolone structural motif in medicinal chemistry: Retrospect and prospect.

The pyrazolone structural motif is a critical element of drugs aimed at different biological end-points. Medicinal chemistry researches have synthesized drug-like pyrazolone candidates with several medicinal features including antimicrobial, antitumor, CNS (central nervous system) effect, anti-inflammatory activities and so on. Meanwhile, SAR (Structure-Activity Relationship) investigations have drawn attentions among medicinal chemists, along with a plenty of analogues have been derived for multiple targets. In this review, we comprehensively summarize the biological activity and SAR for pyrazolone analogues, wishing to give an overall retrospect and prospect on the pyrazolone derivatives.

Synthesis and anti-tyrosinase mechanism of the substituted vanillyl cinnamate analogues.

This study aimed to synthesize and screen tyrosinase inhibitors for delay fruit browning. A series of vanillyl cinnamate analogues were designed and synthesized by simple processes, and the inhibitory effects of all the synthesized derivatives on mushroom tyrosinase were evaluated. In the enzymatic activity test, compounds 21, 22, and 26 had significant (P < 0.05) effect on mushroom tyrosinase at a preliminary screening dose (1 mg/mL in vitro). IC50 analysis showed that the IC50 values of compounds 21, 22 and 26 were 268.5 µM, 213.2 µM and 413.5 µM, respectively. In the cytotoxicity evaluation, Cell Counting Kit-8 (CCK-8) assay showed that compounds 21, 22 and 26 had no significant effect on the proliferation of hepatocyte L02 and B16 melanoma cells at the dosage of 25-200 µM. Inhibition of tyrosinase activity and melanin content in B16 melanoma cells investigations indicated that compounds 21, 22 and 26 inhibited both cellular tyrosinase activity and melanin content dose-dependently and more strongly than the reference standard arbutin. The UV-visible spectra showed compound 22 inhibits the formation of dopamine quinone, further the molecular docking analysis of compound 22 with tyrosinase (PDB: 2Y9X) indicated that compound 22 interacted with the amino acid residues of tyrosinase. The results of anti-browning test showed that compounds 21, 22 and 26 had significant tyrosinase inhibition and anti-browning effects on fresh-cut apple slices at 4 °C in 48 h. Compound 22 could be used as novel tyrosinase inhibitor to delay fruit browning.

Synthesis toward Bivalent Ligands for the Dopamine D2 and Metabotropic Glutamate 5 Receptors.

In this study, we designed and synthesized heterobivalent ligands targeting heteromers consisting of the metabotropic glutamate 5 receptor (mGluR5) and the dopamine D2 receptor (D2R). Bivalent ligand 22a with a linker consisting of 20 atoms showed 4-fold increase in affinity for cells coexpressing D2R and mGluR5 compared to cells solely expressing D2R. Likewise, the affinity of 22a for mGluR5 increased 2-fold in the coexpressing cells. Additionally, 22a exhibited a 5-fold higher mGluR5 affinity than its monovalent precursor 21a in cells coexpressing D2R and mGluR5. These results indicate that 22a is able to bridge binding sites on both receptors constituting the heterodimer. Likewise, cAMP assays revealed that 22a had a 4-fold higher potency in stable D2R and mGluR5 coexpressing cell lines than 1. Furthermore, molecular modeling reveals that 22a is able to simultaneously bind both receptors by passing between the TM5-TM6 interface and establishing six protein-ligand H-bonds.