Synthesis,biological evaluation,and docking studies of some 5‐chloro‐2(3H)‐benzoxazolone Mannich bases derivatives as cholinesterase inhibitors

A series of N‐substituted‐5‐chloro‐2(3H)‐benzoxazolone derivatives were synthesized and evaluated for their acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) inhibitory, and antioxidant activities. The structures of the title compounds were confirmed by spectral and elemental analyses. The cholinesterase (ChE) inhibitory activity studies were carried out using Ellman's colorimetric method. The free radical scavenging activity was also determined by in vitro ABTS (2,2‐azinobis(3‐ethylbenzothiazoline‐6‐sulfonic acid)) assay. The biological activity results revealed that all of the title compounds displayed higher AChE inhibitory activity than the reference compound, rivastigmine, and were selective for AChE. Among the tested compounds, compound 7 exhibited the highest inhibition against AChE (IC₅₀ = 7.53 ± 0.17 μM), while compound 11 was found to be the most active compound against BuChE (IC₅₀ = 17.50 ± 0.29 μM). The molecular docking study of compound 7 showed that this compound can interact with the catalytic active site (CAS) of AChE and also has potential metal chelating ability and a proper log P value. On the other hand, compound 2 bearing a methyl substituent at the ortho position on the phenyl ring showed better radical scavenging activity (IC₅₀ = 1.04 ± 0.04 mM) than Trolox (IC₅₀ = 1.50 ± 0.05 mM).

     

2-(2,4-二氟苯基)-3-(N-甲基-N-取代基酰胺基)-1-(1H 1,2,4-三唑-1-基)-2-丙醇类化合物的合成及抗真菌活性的研究

目的:寻找新的高效、低毒、广谱的抗真菌药物。方法:设计合成了21 个三唑类化合物作为真菌细胞色素P450 14α-去甲基化酶的抑制剂,并通过体外抗真菌实验测定其抗真菌活性。结果:21 个化合物均为新化合物。体外抗真菌试验表明所有目标化合物对试验真菌均有不同程度的抑制作用,特别是对白色念珠菌和近平滑念珠菌具有很好的活性。结论:所有化合物都不同程度地对真菌细胞色素P450 14α-去甲基化酶有抑制作用,化合物15 对8 种不同真菌均显示了较高的活性,有进一步研究价值。     

New N-phenylacetamide-linked 1,2,3-triazole-tethered coumarin conjugates: Synthesis,bioevaluation, and molecular docking study

A series of new 1,2,3-triazole-tethered coumarin conjugates linked by N-phenylacetamide was efficiently synthesized via the click chemistry approach in excellent yields. The synthesized conjugates were evaluated for their in vitro antifungal and antioxidant activities. Antifungal activity determination was carried out against fungal strains such as Candida albicans, Fusarium oxysporum, Aspergillus flavus, Aspergillus niger and Cryptococcus neoformans. Compounds 7b , 7d , 7e , 8b and 8e displayed higher potency than the standard drug miconazole, with lower minimum inhibitory concentration values. Also, compound 7a exhibited potential radical scavenging activity as compared with the standard antioxidant butylated hydroxytoluene. In addition, a molecular docking study of the newly synthesized compounds was carried out, and the results showed a good binding mode at the active site of the fungal (C. albicans) P450 cytochrome lanosterol 14α-demethylase enzyme. Furthermore, the synthesized compounds were also tested for ADME properties, and they demonstrated potential as good candidates for oral drugs.     

Design,synthesis, antileishmanial,and antifungal biological evaluation of novel 3,5-disubstituted isoxazole compounds based on 5-nitrofuran scaffolds

Nineteen 3,5-disubstituted-isoxazole analogs were synthesized based on nitrofuran scaffolds, by a [3 + 2] cycloaddition reaction between terminal acetylenes and 5-nitrofuran chloro-oxime. The compounds were obtained in moderate to very good yields (45–91%). The antileishmanial activity was assayed against the promastigote and amastigote forms of Leishmania (Leishmania) amazonensis. Alkylchlorinated compounds 14p–r were active on both the promastigote and amastigote forms, with emphasis on compound 14p , which showed strong activity against the amastigote form (IC₅₀ = 0.6 μM and selectivity index [SI] = 5.2). In the alkyl series, compound 14o stands out with an IC₅₀ = 8.5 μM and SI = 8.0 on the amastigote form. In the aromatic series, the most active compounds were those containing electron-donor groups, such as trimethoxy isoxazole 14g (IC₅₀ = 1.2 μM and SI = 20.2); compound 14h , with IC₅₀ = 7.0 μM and SI = 6.1; and compound 14j containing the 4-SCH₃ group, with IC₅₀ = 5.7 μM and SI = 10.2. In addition, the antifungal activity of 19 nitrofuran isoxazoles was evaluated against five strains of Candida (C. albicans, C. parapsilosis, C. krusei, C. tropicalis, and C. glabrata). Eleven isoxazole derivatives were active against C. parapsilosis, and compound 14o was found to be the most active (minimal inhibitory concentration [MIC] = 3.4 μM) for this strain. Compound 14p was active against all the strains tested, with an MIC = 17.5 μM for C. glabrata, lower than that of the fluconazole used as the reference drug.     

Synthesis,crystal structure,and ADME prediction studies of novel imidazopyrimidines as antibacterial and cytotoxic agents

In the present study, a novel series of polyfunctionalized imidazopyrimidines 6a–u and 9a–d were efficiently constructed by a domino reaction between 2-imino-6-substituted-2,3-dihydropyrimidin-4(1H)-ones 4a–d or 8a–c and 2-bromoacetophenones 5a–i under mild basic conditions. The synthesized series were screened for their antibacterial activity against Staphylococcus aureus and Bacillus subtilis as Gram-positive (+) bacteria, as well as against Gram-negative (−) bacteria Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Salmonella typhi. Most of the synthesized derivatives of imidazopyrimidines 6 and 9 showed remarkable selectivity against Gram(−) bacteria over the Gram(+) ones. Compounds 6c , 6f , and 6g displayed potent and broad-spectrum antibacterial activity against all tested strains. Compounds 6f and 6g displayed promising inhibitory activity on GryB ATPase from E. coli with IC₅₀ = 1.14 and 0.73 μM, respectively. Simultaneously, some of the synthesized imidazopyrimidines were screened for their antiproliferative activity against 60 cancer cell lines at a concentration of 10 μM. Compound 9d showed potent activity against most of the tested cell lines, with a mean growth inhibition of 37%. The ADME (absorption, distribution, metabolism, and excretion) prediction study demonstrated that the synthesized hits have, in addition to their promising chemotherapeutic activity, acceptable pharmacokinetic properties, and a drug-likeness nature to be further developed.     

Design,synthesis, and anticancer evaluation of N6-hydrazone purine derivatives with potential antiplatelet aggregation activity

In our research on novel anticancer agents, a series of N⁶-hydrazone purine derivatives were designed and synthesized by analysis of a pharmacophore model for ATP-competitive inhibitors. The activities screening results showed that N⁶-hydrazone purine derivatives 21 and 26 not only showed potential antiproliferative activity against the A549 and MCF-7 cell lines comparable to Vandetanib as a positive control but also had moderate antiplatelet aggregation activity. In order to investigate the possible targets, a molecular docking study was carried out on the fourteen kinases associated with anticancer and antiplatelet aggregation activities. The results indicated that compounds 21 and 26 had the potential activity to target VEGFR-2, PI3Kα, EGFR, and HER2 kinases. The inhibition of the kinases assay showed that compound 26 could target VEGFR-2, PI3Kα, and EGFR (IC₅₀ = 0.822, 3.040 and 6.625 μM). All results indicated that compound 26 will be an encouraging framework as potential new multi-target anticancer agent with potential antiplatelet aggregation activity.     

Synthesis of Novel Pyrimidin‐4‐One Bearing Piperazine Ring‐Based Amides as Glycogen Synthase Kinase‐3β Inhibitors with Antidepressant Activity

Novel pyrimidin‐4‐one derivatives have been synthesized using EDC coupling and evaluated as glycogen synthase kinase‐3β (GSK‐3β) inhibitors. Among all the synthesized compounds, compound 5 (3‐methyl‐6‐phenyl‐2‐(piperazin‐1‐yl)‐3,4‐dihydropyrimidin‐4‐one) exhibited the most potent inhibitory activity against GSK‐3β with IC₅₀ value of 74 nm . The molecular docking studies were performed to elucidate the binding modes of the compounds with the target, and a crucial interaction involving hydrogen bond formation with Val‐135 to the active site of GSK‐3β was observed. Furthermore, the synthesized compounds were subjected to in vivo evaluation of their antidepressant activity, and compound 5 showing highest inhibition of GSK‐3β was also found to significantly reduce the duration of immobility at 50 mg/kg, when compared with fluoxetine, a known antidepressant drug. The results of our study suggest that compound 5 may serve as a valuable template for the design and development of inhibitors of GSK‐3β with antidepressant activity.     

Design and Synthesis of Butenolide‐based Novel Benzyl Pyrrolones: Their TNF‐α based Molecular Docking with In vivo and In vitro Anti‐inflammatory Activity

A focused library of novel benzyl pyrrolones has been synthesized and their in silico molecular docking studies carried out against TNF‐α target. Among all the docked molecules, compound 3f showed best glide score of ?6.89. All the synthesized compounds were evaluated for in vivo anti‐inflammatory activity by carrageenan‐induced paw edema model. Compounds showing significant anti‐inflammatory activity were further tested for their in vitro TNF α expression. Compounds 3b and 2b were found to show significant inhibition of 76.22% and 71.47%, respectively after 5 h in comparison with standard drug indomethacin, which showed 80.98% inhibition of inflammation. Compounds 3b and 2b also suppressed TNF α level by 65.03% and 60.90% as compared indomethacin, which showed 68.84% of inhibition. Compound 3b showed significant analgesic activity of 60.04%, and its activity was comparable with indomethacin (64.04%). Compounds 3b and 2b were also tested for their effect on protein expression of COX‐2 and NF‐κB in the liver tissues. Compounds 3b and 2b were further evaluated for their gastric risk and lipid peroxidation action and showed superior GI safety along with reduction of LPO as compared to indomethacin. Hepatotoxicity study showed that these two compounds did not cause any damage to liver.     

Molluskizid wirksame Spiro-α-methylen-γ-butyrolactone

α-Methylene-γ-butyrolactones with Molluscicidal Activity The α-methylene-γ-butyrolactones 1-28 were tested in vitro for molluscicidal activity against Biomphalaria glabrata. The racemic compound 25 shows the best activity. The synthesis was carried out by modified Reformatzky reaction of the corresponding carbonyl compounds and bromomethylacrylic acid ethyl ester. 7-10, 17 and 22-27 have been synthesized for the first time.     

Design,Synthesis, and In Vitro Evaluation of Novel 3, 7‐Disubstituted Coumarin Derivatives as Potent Anticancer Agents

Twenty‐seven 3, 7‐disubstituted coumarin derivatives were designed, synthesized, and evaluated in vitro as anticancer agents. Most of the compounds showed moderate‐to‐potent antiproliferative activity against K562 cells. Compounds 7b and 7d were chosen to evaluate the concentration of 50% growth inhibition (GI₅₀) against SN12C, OVCAR, BxPC‐3, KATO‐III, T24, SNU‐1, WiDr, HeLa, K562, and AGS cell lines. The most potent compound 7d was selected for further cell cycle arrest assay in the AGS cell line. The in vitro data indicated that methylation of benzimidazole moiety at the 3‐position of coumarin exhibited significant enhancement of anticancer activity. This study should provide important information for further modification and optimization of coumarin derivatives as anticancer agents.     

Design and development of some thiazole‐based flavanoids as novel antibacterial against pathogens causing surgical site infection for possible benefit in bone trauma via inhibition of DNA gyrase

In this study, a novel class of hybrid thiazole‐based flavanoid derivatives were synthesized and characterized by FT ‐IR , ¹H‐NMR , ¹³C‐NMR , mass and elemental analysis. These derivatives were evaluated for antibacterial activity for possible benefit in bone trauma via inhibition of DNA gyrase enzyme. Results suggested that compounds 9n , 9o , and 9p showed considerable inhibition of DNA gyrase with considerable activity against tested forty strains of Staphylococcus aureus clinical isolates. Moreover, compound 9n showed hydrogen bonding with LYS 460 along with low binding free energy of ?4.36 kcal/mol against DNA gyrase enzyme. The hemolytic activity of the potent compounds showed mild to no activity together with excellent pharmacokinetics, suggesting to have a potential for the development of designed compounds as novel antibacterial agents.     

Synthesis and Antifungal Activity of 1‐Aryl‐3‐phenethylamino‐1‐propanone Hydrochlorides and 3‐Aroyl‐4‐aryl‐1‐phenethyl‐4‐piperidinols

Mono‐Mannich bases, 1‐aryl‐3‐phenethylamino‐1‐propanone hydrochlorides, 1a, 2a , 3a , 4a , 5a , 6a , 7a , 8a , 9a , and semi‐cyclic mono‐Mannich bases, 3‐aroyl‐4‐aryl‐1‐phenethyl‐4‐piperidinols, 1b , 2b , 3b , 4b , 5b , 6b , 7b , 8b , 9b , were synthesized by a non‐classical Mannich reaction. The aryl part was: C₆H₅ for 1a , 1b ; 4‐CH₃C₆H₄ for 2a , 2b ; 4‐CH₃OC₆H₄ for 3a , 3b ; 4‐ClC₆H₄ for 4a , 4b ; 4‐FC₆H₄ for 5a , 5b ; 4‐BrC₆H₄ for 6a , 6b ; 2,4‐(Cl)₂C₆H₃ for 7a , 7b ; 4‐NO₂C₆H₄ for 8a , 8b ; and C₄H₃S(2‐yl) i. e., 2‐thienyl for 9a , 9b . Piperidinol compounds 2b , 3b , 4b , 5b , 7b , 8b , and 9b are reported here for the first time. The synthesized compounds were tested against seven types of plant pathogenic fungi and three types of human pathogenic fungi using the agar dilution assay. Itraconazole was tested against Candida parapsilosis as the reference compound, while Nystatin was tested as the reference compound against the other fungi. Compounds 1a , 1b , 2a , 4a , 4b , 5a , 5b , 6a , 7a , 8a , 9a , and 9b can be selected as model compounds to develop new antifungal agents against the human pathogen Microsporum canis. Compounds 8a and 8b , which had a similar antifungal activity compared with the reference compound Nystatin against the plant pathogen Aspergillus flavus, can serve as model compounds to develop new antifungal agents to solve agricultural problems.     

Synthesis of 1,2,5(6)-Trisubstituted Benzimidazoles and Evaluation of Their Antimicrobial Activities

A series of 22 benzimidazoles, having several substituents on the azole and benzene nuclei, were prepared and evaluated in vitro for antimicrobial activity. At first 2-chloro or 2-chloromethyl-5(6)-substituted-1H-benzimidazoles were synthesized, which were then substituted at C-2 with several piperazine or piperidine derivatives. The antibacterial activity of these compounds against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa, and the antifungal activity against Candida albicans, Candida stellatoidea, Candida parapsilosis, and Candida pseudotropicalis were determined as the MIC values. Since compound 12 exhibits good activity, in order to clarify the effect of substituents at C-1 on the activity, benzimidazole derivatives having ethyl, allyl, benzyl, and p-fluorobenzyl substituents at C-1 were prepared, and slightly increased activity was seen.     

3-(R)-(碱基)-4-(S)-羟基-5-(R)-羟亚甲基四氢呋喃的合成及抗肿瘤活性

目的：研究一系列3-(R)-单脱氧异核苷的合成和抗肿瘤活性。方法和结果：由L-木糖出发,合成了环氧化物5-(R)-二甲氧甲基-3(S),4(S)-环氧四氢呋喃4;在碱性条件下,利用嘌呤的N⁹位或嘧啶的N¹位对环氧化物进行亲核进攻,得到一系列3-(R)-单脱氧异核苷5a-d和6a-d;并进行了体外抗肿瘤活性筛选。结论：其中3-(R)-单脱氧异核苷5a-d为首次报道;同已报道的3-(S)-单脱氧异核苷合成方法相比,路线缩短,收率提高。在体外抗肿瘤和端粒酶抑制活性筛选中,只有化合物6a显示了对BIU细胞较弱的抑制活性,其余均未显示有意义的抗肿瘤活性和端粒酶抑制活性。     

1-{2-[(4-取代苯基)甲氧基]-2-(取代苯基)乙基}-1H-氮唑类化合物的合成及抗真菌活性

根据氮唑类抗真菌化合物的构效关系和作用机理,设计合成了29个1-{2-[(4-取代苯基)甲氧基]-2-(取代苯基)乙基}-1H-氮唑类化合物,其中九个为首次报道。初步体外抑菌试验结果表明,大多数目标化合物对八种试验菌株都有不同程度的抗真菌活性。化合物14对白念珠菌的活性与克霉唑及益康唑相当,对其它七种试验菌株的活性明显强于克霉唑及益康唑。化合物4,12对白念珠菌活性差,对其它七种试验菌株的活性也强于克霉唑和益康唑。化合物5,6和23除对白念珠菌外,对其它七种试验菌株,也有较强活性。     

Synthesis and structure-activity relationships of a novel class of dithiocarbamic acid esters as anticancer agent

Based on a novel lead compound 4‐methylpiperazine‐1‐carbodithioic acid 3‐cyano‐3,3‐diphenylpropyl ester 1 , the systematic structural modification was carried out. All the synthesized compounds were evaluated for their in‐vitro anticancer activities on four to six different cell lines at three different concentrations. Most of the tested compounds could selectively inhibit the growth of HL‐60 and Bel‐7402 cell lines at a medium concentration. Four compounds ( 3f , 3g , 3n , and 5 ) were selected for the IC₅₀ test, and the results revealed that three compounds ( 3g , 3n , and 5 ) showed almost the same or a slightly weaker activity than compound 1 against HL‐60, and three compounds ( 3f , 3g , and 3n ) showed >2‐fold higher potency than compound 1 against Bel‐7402. The in‐vivo efficacy of 3n · HCl was evaluated with transplanted hepatocyte carcinoma 22 as an in‐vivo test model. It was found that 3n · HCl could inhibit significantly the growth of tumor, and that this effect was dose‐dependent. Meanwhile, the compound 3n · HCl showed low toxicity compared with compound 1 · HCl as evidenced by the little body‐weight loss. These results confirmed that compound 3n · HCl is more potent than the lead compound 1 · HCl . Preliminary structure–activity relationships indicated that: a) Both nitrile group and the cyclic amine containing at least two nitrogens were indispensable moieties to keep the activity; b) substitution of the piperazine ring is unfavorable for the improvement of activity; c) the suitable linker joining the piperazinyl dithiocarboxyl and diphenylacetonitril group should be ethylene; d) a non‐coplanar arrangement of the two benzene rings appears to be essential for activity.     

Synthesis,HIV-1 RT inhibitory,antibacterial, antifungal and binding mode studies of some novel N-substituted 5-benzylidine-2,4-thiazolidinediones

Background

Structural modifications of thiazolidinediones at 3^rd and 5^th position have exhibited significant biological activities. In view of the facts, and based on in silico studies carried out on thiazolidine-2,4-diones as HIV-1- RT inhibitors, a novel series of 2,4-thiazolidinedione analogs have been designed and synthesized.

Methods

Title compounds were prepared by the reported method. Conformations of the structures were assigned on the basis of results of different spectral data. The assay of HIV-1 RT was done as reported by Silprasit et al. Antimicrobial activity was determined by two fold serial dilution method. Docking study was performed for the highest active compounds by using Glide 5.0.

Results

The newly synthesized compounds were evaluated for their HIV-1 RT inhibitory activity. Among the synthesized compounds, compound 24 showed significant HIV-1 RT inhibitory activity with 73% of inhibition with an IC₅₀ value of 1.31 μM. Compound 10 showed highest activity against all the bacterial strains.A molecular modeling study was carried out in order to investigate the possible interactions of the highest active compounds 24, 10 and 4 with the non nucleoside inhibitory binding pocket(NNIBP) of RT, active site of GlcN-6-P synthase and cytochrome P450 14-α-sterol demethylase from Candida albicans (Candida P450DM) as the target receptors respectively using the Extra Precision (XP) mode of Glide software.

Conclusion

A series of novel substituted 2-(5-benzylidene-2,4-dioxothiazolidin-3-yl)-N-(phenyl)propanamides (4–31) have been synthesized and evaluated for their HIV-1 RT inhibitory activity, antibacterial and antifungal activities. Some of the compounds have shown significant activity. Molecular docking studies showed very good interaction.     

1,3,4-Thiadiazole and 1,2,4-triazole-5-thione derivatives bearing 2-pentyl-5-phenyl-2,4-dihydro-3H-1,2,4-triazole-3-one ring: Synthesis,molecular docking,urease inhibition,and crystal structure

Two series of 1,3,4-thiadiazole ( 40a–o ) and 1,2,4-triazole-5-thione ( 41a–l ) derivatives bearing a 2-pentyl-5-phenyl-1,2,4-triazole-3-one ring were synthesized and then studied for their urease inhibitory activities using thiourea as a standard drug. Among the two groups, the first group ( 40a–o ) did not show good activity while the second group ( 41a–l ) showed excellent activity. Compound 41j (1091.24 ± 14.02 µM) of the second series of compounds showed lower activity than thiourea, while the remaining 11 compounds ( 41a–i , k , and l ) showed better activity than thiourea (183.92 ± 13.14 µM). Among the 11 compounds, 41b (15.96 ± 2.28 µM) having the 3-F group on the phenyl ring showed the highest inhibitory activity. Urease kinetic studies of 41b , which is the most active compound, determined it to have an un-competitive inhibition potential. Moreover, in silico analysis against urease from jack bean with 27 new heterocyclic compounds and the reference molecule was carried out to see the necessary interactions responsible for urease activity. The docking calculations of all compounds supported stronger binding to the receptor than the reference molecule, with high inhibition constants. In addition, compound 40m was characterized by single-crystal X-ray diffraction analysis. X-ray analysis reveals that the structures of the compound 40m crystallize in the monoclinic P21/c space group with the cell parameters: a = 10.2155(9) Å, b = 22.1709(18) Å, c = 21.4858(17) Å, β = 99.677(8)°, V = 4797.0(7) ų. X-ray diffraction analyses were also performed to gain insights into the role of weak intermolecular interactions and C-H…X (halogen) interactions in compound 40m that influence the crystal packing.