Synthesis and biological evaluation of a new series of cinnamic acid amide derivatives as potent haemostatic agents containing a 2-aminothiazole substructure

Ten new cinnamic acid derivatives containing a 2-aminothiazole substructure were designed and synthesized. This series of compounds exhibited good thermostabilities as demonstrated by thermogravimetric analysis. In coagulation assays (prothrombin time, activated partial thromboplastin time and thrombin time) in vitro, most compounds demonstrated excellent activities to promote blood coagulation. Among the studied series, compounds N1, N4, N5 and W5 exhibited a significant coagulation activity. Further studies indicated that compound N5 (IC₅₀ = 1.87 μmol/L) displayed the most suitable efficacy of promoting platelet aggregation than the clinically used haemostatic drug etamsylate (IC₅₀ = 46.22 μmol/L). Furthermore, the relationship between the functional groups of the compounds and the corresponding blood coagulant activity was explored in this study.     

Design,synthesis and cytotoxic activities of scopoletin-isoxazole and scopoletin-pyrazole hybrids

12 novel scopoletin-isoxazole and scopoletin-pyrazole hybrids were designed, synthesized and their chemical structures were confirmed by HR-MS, IR, ¹H NMR and ¹³C NMR spectra. The anticancer activities of the newly synthesized compounds were evaluated in vitro against three human cancer cell lines including HCT-116, Hun7 and SW620 by MTT assay. The screening results showed that six compounds (9a, 9c, 9d, 12a, 18b and 18d) exhibited potent cytotoxic activities with IC₅₀ values below 20 μM. Besides, we have further evaluated the growth inhibitory activities of six compounds against the human normal tissue cell lines HFL-1. Especially, compound 9d displayed significant anti-proliferative activity with IC₅₀ values ranging from 8.76 μM to 9.83 μM and weak cytotoxicity with IC₅₀ value of 90.9 μM on normal cells HFL-1, which suggested that isoxazole-based hybrids of scopoletin were an effective chemical modification to improve the anticancer activity of scopoletin.     

Design,synthesis and fungicidal activity of novel 2-substituted aminocycloalkylsulfonamides

A series of novel 2-substituted aminocycloalkylsulfonamides were designed and synthesized by highly selective N-alkylation reaction, whose structures were characterized by ¹H NMR, ¹³C NMR and HRMS. Among them, the configuration of compounds III12 and III20 were confirmed by X-ray single crystal diffraction. Bioassays demonstrated that the title compounds had considerable effects on different strains of Botrytis cinerea and Pyricularia grisea. Comparing with positive control procymidone (EC₅₀ = 10.31 mg/L), compounds III28, III29, III30 and III31 showed excellent fungicidal activity against a strain of B. cinerea (CY-09), with EC₅₀ values of 3.17, 3.04, 2.54 and 1.99 mg/L respectively. Their in vivo fungicidal activities were also better than the positive controls cyprodinil, procymidone, boscalid and carbendazim in pot experiments. Moreover, the fungicidal activity of III28 (EC₅₀ = 4.62 mg/L) against P. grisea was also better than that of the positive control isoprothiolane (EC₅₀ = 6.11 mg/L). Compound III28 would be great promise as a hit compound for further study based on the structure-activity relationship.     

Bifunctional bisphosphonate derivatives and platinum complexes with high affinity for bone hydroxyapatite

A series of ethylenediamine/1,3-propanediamine derivatives containing bifunctional bisphosphonate substituents and their corresponding dichloroplatinum(II) complexes have been synthesized and characterized by elemental analysis, ¹H NMR, ¹³C NMR, ³¹P NMR, and HRMS spectra. Based on WST-8 assay with CCK-8, in general, the newly synthesized dichloroplatinum complexes 1–6 showed higher in vitro antitumor activity than platinum-free compounds L1–L6 against three tumor cell lines (especially osteosarcoma MG-63). According to hydroxyapatite binding experiment, complexes 2, 3, and 6 showed much higher affinity (K′ = 3.7, 4.0, and 3.0, respectively) for bone hydroxyapatite than cisplatin (K′ < 0.1), comparable to zoledronate (K′ = 2.8). It can be found that representative complex 2 with high cytotoxicity and in vitro antiproliferative activity against osteosarcoma cell line, as well as promising hydroxyapatite binding ability has been screened as a potential bone-targeting antitumor agent for subsequent in vivo study. In addition, flow cytometry experiment was applied to investigate the mode of action of representative complex 2.     

Design,synthesis, and bioactivities of novel oxadiazole-substituted pyrazole oximes

A series of novel pyrazole oxime derivatives containing a substituted oxadiazole group were designed and synthesized. The bioassay results indicated that some title compounds displayed good acaricidal and insecticidal activities against Tetranychus cinnabarinus, Aphis medicaginis, Oriental armyworm, and Nilaparvata lugens. Especially, compounds 7a, 7b, and 7c had 80%, 90%, and 90% insecticidal activities against A. medicaginis at 20 μg/mL, respectively. Interestingly, some of the designed compounds displayed wonderful fungicidal activities in vivo against cucumber Pseudoperonospora cubensis. Furthermore, compounds 7a (EC₅₀ = 4.97 μg/mL) and 7h (EC₅₀ = 0.51 μg/mL) showed excellent fungicidal activity against P. cubensis comparable or better than that of the control Pyraclostrobin (EC₅₀ = 4.59 μg/mL).     

Design,synthesis and biological evaluation of 8-substituted-6-hydrazonoindolo[2,1-b]quinazolin-12(6H)-one scaffolds as potential cytotoxic agents: IDO-1 targeting molecular docking studies

Herein, we have reported the synthesis of 18 novel 8-substituted tryptanthrin analogues based on our earlier work. All these tryptanthrin analogues were well characterized by ¹H & ¹³C NMR, FT-IR, Mass Spectrometry and Elemental Analysis. All these 8-substituted analogues were screened for their anti-oxidant activity by DPPH radical scavenging assay. Out of all the tested compounds, T¹¹, T¹², T¹⁷ and T¹⁸ showed potent anti-oxidant activity. The anti-cancer activity have been performed by using MTT assay protocol and their results depicts that compounds having the 4-pyridyl or 4-carboxyphenyl substituents at the 8th position of the tryptanthrin framework are found to be the most promising cytotoxic agent against A549, MCF-7 and HeLa human cancer cell lines compared to others as well as with the standard drug cisplatin. Moreover, the comparative molecular docking studies against the three protein receptors IDO1, EGFR and HER2 strongly suggested that IDO1 is the best target protein, which exhibits lowest binding energies of ?11.73 and ?11.61 kcal mol^?1 for T¹¹ and T¹² scaffolds, respectively towards the in vitro anti-cancer activity.     

Synthesis and QSAR study of novel α-methylene-γ-butyrolactone derivatives as antifungal agents

Thirty-six new α-benzylidene-γ-lactone compounds based α-methylene-γ-butyrolactone substructure were prepared and characterized by spectroscopic analysis. All compounds were evaluated for antifungal activities in vitro against six plant pathogenic fungi and the half maximal inhibitory concentration (IC₅₀) against Botrytis cinerea and Colletotrichum lagenarium were investigated. Compounds 5c-3 and 5c-5 with the halogen atom exhibited excellent fungicidal activity against B. cinerea (IC₅₀ = 22.91, 18.89 μM). The structure-activity relationships (SARs) analysis indicated that the derivatives with electron-withdrawing substituents at the meta- or para-positions improves the activity. Via the heuristic method, the generated quantitative structure-activity relationship (QSAR) model (R² = 0.961) revealed a strong correlation of antifungal activity against B. cinerea with molecular structures of these compounds. Meanwhile, the cytotoxicity of 20 representative derivatives was tested in the human tumor cells line (HepG2) and the hepatic L02 cells line, the result indicated that the synthesized compounds showed significant inhibitory activity and limited selectivity. Compound 5c-5 has the highest fungicidal activity with IC₅₀ = 18.89 μM (against B. cinerea.) but low cytotoxicity with IC₅₀ = 35.4 μM (against HepG2 cell line) and IC₅₀ = 68.8 μM (against Hepatic L02 cell line). These encouraging results can be providing an alternative, promising use of α-benzylidene-γ-lactone through the design and exploration of eco-friendly fungicides with low toxicity and high efficiency.     

Synthesis,screening and docking analysis of hispolon analogs as potential antitubercular agents

A series of 20 hispolons/dihydrohispolons were synthesized and characterized by spectral data. These compounds were subjected to in vitro antitubercular activity screening against Mycobacterium tuberculosis (H37Rv) strain. The synthesized compounds showed varied antitubercular activity ranging from 100 to 1.6 μg/mL. Among the screened compounds, four compounds (H1, H2, H3 and H15) have shown moderate activity with MIC 25 μg/mL. Potent activities were observed for the dihydrohispolon derivative H14 (MIC 1.6 μg/mL) followed by H13 (6.25 μg/mL) and H17 (12.5 μg/mL), H19 (3.125 μg/ML). Docking simulations gave good insights on the possible interactions between the tested compounds and β-keto acyl synthase enzyme (mtbFabH). Drug-inhibitor combination studies showed no synergism with the drugs targeting mycolic acid biosynthesis (isoniazid, ethambutol and thiolactomycin, a specific inhibitor of KAS-B enzyme) but showed significant synergism with other drugs including rifampicin and ciprofloxacin ascertaining the drug target for hispolons as inhibition of mycolic acid biosynthesis, probably via mtbFabH.     

Design,synthesis and antifungal activity of novel fenfuram-diarylamine hybrids

Ten novel fenfuram-diarylamine hybrids were designed and synthesized. And their antifungal activities against four phytopathogenic fungi have been evaluated in vitro and most of the compounds demonstrated a significant antifungal activities against Rhizoctonia solani and Sclerotinia sclerotiorum. Compound 5e exhibited the most potent antifungal activity against R. solani with an EC₅₀ value of 0.037 mg/L, far superior to the commercially available fungicide boscalid (EC₅₀ = 1.71 mg/L) and lead fungicide fenfuram (EC₅₀ = 6.18 mg/L). Furthermore, scanning electron microscopy images showed that the mycelia on treated media grew abnormally with tenuous, wizened and overlapping colonies compared to the negative control. Molecular docking studies revealed that compound 5e featured a higher affinity for succinate dehydrogenase (SDH) than fenfuram. Furthermore, it was shown that the 3-chlorophenyl group in compound 5e formed a CH-π interaction with B/Trp-206 and a Cl-π interaction with D/Tyr-128, rendering compound 5e more active than fenfuram against SDH.     

Study of antileishmanial activity of 2-aminobenzoyl amino acid hydrazides and their quinazoline derivatives

A new small library of 2-aminobenzoyl amino acid hydrazide derivatives and quinazolinones derivatives was synthesized and fully characterized by IR, NMR, and elemental analysis. The activity of the prepared compounds on the growth of Leishmania aethiopica promastigotes was evaluated. 2-Benzoyl amino acid hydrazide showed higher inhibitory effect than the quinazoline counterpart. The in vitro antipromastigote activity demonstrated that compounds 2a, 2b, 2f and 4a had IC₅₀ better than standard drug miltefosine and comparable activity to amphotericin B deoxycholate, which indicates their high antileishmanial activity against Leishmania. aethiopica. Among the prepared compounds; 2-amino-N-(6-hydrazinyl-6-oxohexyl)benzamide 2f (IC₅₀ = 0.051 μM) has the best activity, 154 folds more active than reference standard drug miltefosine (IC₅₀ = 7.832 μM), and half fold the activity of amphotericin B (IC₅₀ = 0.035 μM). In addition, this compound was safe and well tolerated by experimental animals orally up to 250 mg/kg and parenterally up to 100 mg/kg.     

Antileishmanial potential of fused 5-(pyrazin-2-yl)-4H-1,2,4-triazole-3-thiols: Synthesis,biological evaluations and computational studies

A series of newer 1,2,4-triazole-3-thiol derivatives 5(a–m) and 6(a–i) containing a triazole fused with pyrazine moiety of pharmacological significance have been synthesized. All the synthesized compounds were screened for their in vitro antileishmanial and antioxidant activities. Compounds 5f (IC₅₀ = 79.0 µM) and 6f (IC₅₀ = 79.0 µM) were shown significant antileishmanial activity when compared with standard sodium stibogluconate (IC₅₀ = 490.0 µM). Compounds 5b (IC₅₀ = 13.96 µM) and 6b (IC₅₀ = 13.96 µM) showed significant antioxidant activity. After performing molecular docking study and analyzing overall binding modes it was found that the synthesized compounds had potential to inhibit L. donovani pteridine reductase 1 enzyme. In silico ADME and metabolic site prediction studies were also held out to set an effective lead candidate for the future antileishmanial and antibacterial drug discovery initiatives.     

Synthesis and nematicidal activities of 1,2,3-benzotriazin-4-one derivatives containing thiourea and acylthiourea against Meloidogyne incognita

Two series of novel 1,2,3-benzotriazin-4-one derivatives containing thiourea and acylthiourea were designed and synthesized. The bioassay results showed that most of the test compounds showed good nematicidal activity against M. incognita at the concentration of 10.0 mg L^?1in vivo. The compounds A13, A17 and B3 showed excellent nematicidal activity on the second stage juveniles of the root-knot nematode with the inhibition rate of 51.3%, 58.3% and 51.3% at the concentration of 1.0 mg L^?1 respectively. It suggested that the structure of 1,2,3-benzotriazin-4-one derivatives containing thiourea and acylthiourea could be optimized further.     

Design,synthesis and biological activity evaluation of novel 2,6-difluorobenzamide derivatives through FtsZ inhibition

Novel series of 3-substituted 2,6-difluorobenzamide derivatives as FtsZ inhibitors were designed, synthesized and evaluated for their in vitro antibacterial activity against various phenotype of Gram-positive and Gram-negative bacteria, and their cell division inhibitory activity against three representative strains. As a result, 3-chloroalkoxy derivative 7, 3-bromoalkoxy derivative 12 and 3-alkyloxy derivative 17 were found to exhibit the best antibacterial activity against Bacillus subtilis with MICs of 0.25–1 μg/mL, and good activity (MIC < 10 μg/mL) against both susceptible and resistant Staphylococcus aureus. Additionally, all the three compounds displayed potent cell division inhibitory activity with MIC values of below 1 μg/mL against Bacillus subtilis and Staphylococcus aureus.     

Design,synthesis and anticancer activity of novel nopinone-based thiosemicarbazone derivatives

A series of new nopinone-based thiosemicarbazone derivatives were designed and synthesized as potent anticancer agents. All these compounds were identified by ¹H NMR, ¹³C NMR, HR-MS spectra analyses. In the in vitro anticancer activity, most derivatives showed considerable cytotoxic activity against three human cancer cell lines (MDA-MB-231, SMMC-7721 and Hela). Among them, compound 4i exhibited most potent antitumor activity against three cancer cell lines with the IC₅₀ values of 2.79 ± 0.38, 2.64 ± 0.17 and 3.64 ± 0.13 μM, respectively. Furthermore, the cell cycle analysis indicated that compound 4i caused cell cycle arrest of MDA-MB-231 cells at G2/M phase. The Annexin V-FITC/7-AAD dual staining assay also revealed that compound 4i induced the early apoptosis of MDA-MB-231 cells.     

Design,synthesis, anticancer activity and docking studies of novel 4-morpholino-7,8-dihydro-5H-thiopyrano[4,3-d]pyrimidine derivatives as mTOR inhibitors

A series of 7,8-dihydro-5H-thiopyrano[4,3-d]pyrimidine derivatives (7a–q, 10a–q) were designed, synthesized and their chemical structures were confirmed by ¹H NMR, ¹³C NMR, MS and HRMS spectrum. All the compounds were evaluated for the inhibitory activity against mTOR kinase at 10 μM level. Five selected compounds (7b, 7e, 7h, 10b and 10e) were further evaluated for the inhibitory activity against PI3Kα at 10 μM level, and the IC₅₀ values against mTOR kinase and two cancer cell lines. Twelve of the target compounds exhibited moderate antitumor activities. The most promising compound 7e showed strong antitumor activities against mTOR kinase, H460 and PC-3 cell lines with IC₅₀ values of 0.80 ± 0.15 μM, 7.43 ± 1.45 μM and 11.90 ± 0.94 μM, which were 1.28 to 1.71-fold more active than BMCL-200908069-1 (1.37 ± 0.07 μM, 9.52 ± 0.29 μM, 16.27 ± 0.54 μM), respectively. Structure–activity relationships (SARs) and docking studies indicated that the thiopyrano[4,3-d]pyrimidine scaffolds exerted little effect on antitumor activities of target compounds. Substitutions of aryl group at C-4 position had a significant impact on the antitumor activities, and 4-OH substitution produced the best potency.     

Quinazoline-1-deoxynojirimycin hybrids as high active dual inhibitors of EGFR and α-glucosidase

A series of novel quinazoline-1-deoxynojirimycin hybrids were designed, synthesized and evaluated for their inhibitory activities against two drug target enzymes, epidermal growth factor receptor (EGFR) tyrosine kinase and α-glucosidase. Some synthesized compounds exhibited significantly inhibitory activities against the tested enzymes. Comparing with reference compounds gefitinib and lapatinib, compounds 7d, 8d, 9b and 9d showed higher inhibitory activities against EGFR (IC₅₀: 1.79–10.71 nM). Meanwhile the inhibitory activities of 7d, 8d and 9c against α-glucosidase (IC₅₀ = 0.14, 0.09 and 0.25 µM, respectively) were obvious higher than that of miglitol (IC₅₀ = 2.43 µM), a clinical using α-glucosidase inhibitor. Interestingly, compound 9d as a dual inhibitor showed high inhibitory activity to EGFR^wt tyrosine kinase (IC₅₀ = 1.79 nM), also to α-glucosidase (IC₅₀ = 0.39 µM). The work could be very useful starting point for developing a new series of enzyme inhibitors targeting EGFR and/or α-glucosidase.     

Design,synthesis, biological evaluation and molecular modelling studies of novel diaryl substituted pyrazolyl thiazolidinediones as potent pancreatic lipase inhibitors

A series of novel diaryl substituted pyrazolyl 2,4-thiazolidinediones were synthesized via reaction of appropriate pyrazolecarboxaldehydes with 2,4-thiazolidinedione (TZD) and nitrobenzyl substituted 2,4-thiazolidinedione. The resulting compounds were screened in vitro for pancreatic lipase (PL) inhibitory activity. Two assay protocols were performed viz., methods A and B using p-nitrophenyl butyrate and tributyrin as substrates, respectively. Compound 11e exhibited potent PL inhibitory activity (IC₅₀ = 4.81 µM and X_i50 = 10.01, respectively in method A and B), comparable to that of the standard drug, orlistat (IC₅₀ = 0.99 µM and X_i50 = 3.72). Presence of nitrobenzyl group at N-3 position of TZD and nature of substituent at para position of phenyl ring at C-3 position of pyrazole ring notably affected the PL inhibitory activity of the tested compounds. Enzyme inhibition kinetics of 11e revealed its reversible competitive inhibition, similar to that of orlistat. Molecular docking studies validated the rationale of pharmacophoric design and are in accordance to the in vitro results. Compound 11e exhibited a potential MolDock score of ?153.349 kcal/mol. Further, the diaryl pyrazolyl wing exhibited hydrophobic interactions with the amino acids of the hydrophobic lid domain. Moreover, the carbonyl group at 2^nd position of the TZD ring existed adjacent to Ser 152 (≈3 Å) similar to that of orlistat. A 10 ns molecular dynamics simulation of 11e–PL complex revealed a stable binding conformation of 11e in the active site of PL (Maximum RMSD ≈ 3 Å). The present study identified novel thiazolidinedione based leads with promising PL inhibitory activity. Further development of the leads might result in potent PL inhibitors.     

Design,synthesis and in vitro anticancer activity of novel quinoline and oxadiazole derivatives of ursolic acid

A series of new quinoline derivatives of ursolic acid were designed and synthesized in an attempt to develop potential anticancer agents. The structures of these compounds were identified by ¹H NMR, ¹³C NMR, IR and ESI-MS spectra analysis. The target compounds were evaluated for their in vitro cytotoxicity against three human cancer cell lines (MDA-MB-231, Hela and SMMC-7721). From the results, compounds 3a–d displayed significant antitumor activity against three cancer cell lines. Especially, compound 3b was found to be the most potent derivative with IC₅₀ values of 0.61 ± 0.07, 0.36 ± 0.05, 12.49 ± 0.08 μM against MDA-MB-231, HeLa and SMMC-7721 cells, respectively, stronger than positive control etoposide. Furthermore, the Annexin V-FITC/PI dual staining assay revealed that compound 3b could significantly induce the apoptosis of MDA-MB-231 cells in a dose-dependent manner. The cell cycle analysis also indicated that compound 3b could cause cell cycle arrest of MDA-MB-231 cells at G0/G1 phase.     

Synthesis,biological evaluation and molecular docking studies of chromone hydrazone derivatives as α-glucosidase inhibitors

A series of chromone hydrazone derivatives 4a–4p have been synthesized, characterized by ¹H NMR and ¹³C NMR and evaluated for their in vitro α-glucosidase inhibitory activity. Out of these tested compounds, six (4a, 4b, 4d, 4j, 4o and 4p) displayed potent α-glucosidase inhibitory activity with IC₅₀ values in the range of 20.1 ± 0.19 μM to 45.7 ± 0.23 μM, as compared to the standard drug acarbose (IC₅₀ = 817.38 ± 6.27 μM). Among this series, compound 4d (IC₅₀ = 20.1 ± 0.19 μM) with 4-sulfonamide substitution at phenyl part of hydrazide was found to be the most active compound. Lineweaver-Burk plot analysis indicated that compound 4d is a non-competitive inhibitor of α-glucosidase. The binding interactions of the most active analogs were confirmed through molecular docking studies. Docking studies showed 4d are interacting with the residues Glu-276, Asp-214, Asp-349 and Arg-439 through hydrogen bonds, arene-anion and arene-cation interactions. In summary, our studies shown that these chromone hydrazone derivatives are a new class of α-glucosidase inhibitors.     

Synthesis and anthelmintic activity of arctigenin derivatives against Dactylogyrus intermedius in goldfish

To control the parasitic disease of Dactylogyrus intermedius, a series of new arctigenin derivatives were designed, synthesized and tested in our study. The anthelmintic activity of most of the derivatives ranged from 1 to 10 mg/L. Compared to traditional drug praziquantel (EC₅₀ = 2.69 mg/L), ether derivatives 2g and 2h exhibited slightly higher anti-parasitic activity, with the EC₅₀ values of 2.48 and 1.52 mg/L, respectively. Furthermore, the arctigenin-imidazole hybrids 4a and 4b also removed D. intermedius effectively, with the EC₅₀ values of 2.13 and 2.07 mg/L, respectively. The structure-activity relationship analysis indicated that four carbon atoms length of linker and imidazole substitute group could significantly increase the anthelmintic activity, and reduced the toxicity. Through the scanning electron microscope observation, compounds 4a and 4b caused the D. intermedius tegumental damage such as intensive wrinkles, holes and nodular structures. Overall, the structural optimization analysis of arctigenin suggested that 4a and 4b can be used for preventing and controlling Dactylogyrus infections and considered as promising lead compounds for the development of commercial drugs.