Structure-based design,synthesis and biological evaluation of β-glucuronidase inhibitors

Using structure-based virtual screening approach, a coumarin derivative (1) was identified as β-glucuronidase inhibitor. A focused library of coumarin derivatives was synthesized by eco-benign version of chemical reaction, and all synthetic compounds were characterized by using spectroscopy. These compounds were found to be inhibitor of β-glucuronidase with IC₅₀ values in a micromolar range. All synthetic compounds exhibited interesting inhibitory activity against β-glucuronidase, however, their potency varied substantially from IC₅₀ = 9.9–352.6 µM. Of twenty-one compounds, four exhibited a better inhibitory profile than the initial hit 1. Interestingly, compounds 1e, 1k, 1n and 1p exhibited more potency than the standard inhibitor with IC₅₀ values 34.2, 21.4, 11.7, and 9.9 µM, respectively. We further studied their dose responses and also checked our results by using detergent Triton ×-100. We found that our results are true and not affected by detergent.     

Molecular design,synthesis and biological activities of amidines as new ketol-acid reductoisomerase inhibitors

Diamidine （A） was identified in our in vitro bio-assay as a possible inhibitor of ketol-acid reductoisomerase （KARI） from the ACD database search based on the known three-dimensional crystal structure of KARI. An investigation on interaction of A on KARI active sites, led to the design and synthesis of 15 novel monoamidines. Some of those showed better biological activity than A on rice KARI （in vitro） and in greenhouse herbicidal tests （in vivo）. The structure-biological activity relationship was investigated, which provides valuable information to further study of potential KARI inhibitors.     

The total synthesis and biological evaluation of nafuredin-γ and its analogues

Nafuredin (1) is converted to nafuredin-γ (2) under mild basic conditions and both compounds exhibit the same inhibitory activity and selectivity against NADH-fumarate reductase (complex I). The total synthesis of 2 was achieved by a convergent approach using Stille coupling. The structural elements required for inhibitory activity against NADH-fumarate reductase (complex I) were then investigated by evaluation of nafuredin-γ (2) and its structural analogues.     

Design,synthesis and biological evaluation of sulfenimine cephalosporin sulfoxides as β-lactamase inhibitors

A series of sulfenimine cephalosporin sulfoxide derivatives(7a–v) were designed, synthesized and evaluated for their inhibitory activity against TEM-1 and cephalosporinase in cell-free systems. Some of the tested compounds showed enhanced inhibitory activity against class C b-lactamase cephalosporinase compared with the tazobactam. The most promising compounds 7c and 7n(IC50= 7.6 and8.6 mmol/L, respectively) were further investigated in combination with cefradine against a variety of clinical isolated b-lactamase-producing bacterial strains.     

Pharmacophore-guided design, synthesis and evaluation of quinazoline-arylpiperazines as new α1-adrenoceptor antagonists

A series of arylpiperazinesquinazoline-2,4-diamine compounds were designed and synthesized based on pharmacophore for uro-selectiveα_1-adrenoceptor antagonists and 3D chemical database searching.The in vitro functional analysis showed that compounds 9 and 14 showed better and similarα_1-AR antagonistic activity compared with prazosin.     

Design,synthesis and biological evaluation of novel 2-phenyl-4,5,6,7-tetrahydro-1H-​indole derivatives as potential anticancer agents and tubulin polymerization inhibitors

A new series of 2-phenyl-4,5,6,7-tetrahydro-1H-?indole derivatives as tubulin polymerization inhibitors were synthesized and evaluated for the anti-proliferative activities. All newly prepared compounds were tested for their antiproliferative activity in vitro on the human breast cancer cell line (MCF-7) and human lung adenocarcinoma cell line (A549). Among them, compound 7b with a 4-methoxyl substituent at the phenylhydrazone moiety exhibited the most potent anticancer activity against MCF-7 and A549 with IC₅₀ values of 1.77 ± 0.37 and 3.75 ± 0.11 μM, respectively. Interestingly, 7b displayed significant selectivity in inhibiting cancer cells over LO2 (normal human liver cells). Further mechanism studies revealed that 7b significantly arrested cell cycle at G2/M phase and induced apoptosis in a dose-dependent manner. Additionally, 7b effectively inhibited tubulin polymerization with an inhibitory manner similar to that of colchicine. Furthermore, molecular docking study suggested that 7b had high binding affinities for the colchicine binding pocket of tubulin. Hence, this study demonstrates for the first time that tetrahydroindole can be used as a functional group for the design and development of new tubulin polymerization inhibitors.     

Design,synthesis, biological evaluation,and docking study of new acridine-9-carboxamide linked to 1,2,3-triazole derivatives as antidiabetic agents targeting α-glucosidase

A new series of acridine-9-carboxamide-1,2,3-triazole derivatives 7a-m were designed, synthesized, and evaluated as novel α-glucosidase inhibitors. Acridine-9-carboxamide-1,2,3-triazole scaffold has been designed by combination of effective moieties from potent α-glucosidase inhibitors. Most of the synthesized compounds were more potent than standard inhibitor acarbose. Among the title compounds, the most potent compounds were compounds 7j , 7k , and 7a with IC₅₀ values of 120.2 ± 1.0, 151.1 ± 1.4, and 157.6 ± 1.6 μM, respectively (IC₅₀ value of acarbose = 750.0 ± 10.0 μM). Docking study of the most potent compounds demonstrated that these compounds formed stable complexes with α-glucosidase active site. Anti-α-amylase assay of compounds 7j , 7k , and 7a was performed and no activity was observed. in vitro cytotoxicity assay of the latter compounds revealed that these compounds were not cytotoxic toward human normal (HDF) and cancer (MCF-7) cell lines. ADME and toxicity prediction of compounds 7j , 7k , and 7a were also performed.     

Design,synthesis and biological evaluation of novel quinazoline derivatives as potential NF-κb inhibitors

A series of novel 4-aminoquinazoline derivatives were designed, synthesized and biological properties on nuclear factor-kappaB (NF-κb) pathway inhibitory and potential in vitro anti-proliferation against breast cancer lines were also evaluated. Among them, LU1501 exhibited potent inhibition with IC₅₀ values in SK-BR-3 (10.16 ± 0.86 µM) and HCC1806 (10.66 ± 1.01 µM) cell lines. In vivo studies in breast cancer tumor model proved the correlation between anticancer activity of LU1501 and proliferation inhibition through the NF-κb signal pathway. The molecular docking studies also portrayed the potential binding mechanism between LU1501 and the key proteins of p65 and IkBα in NF-κb pathway. Accordingly, compound LU1501 could serve as a potent agent against breast cancer for further investigation.     

Novel Schiff bases–based thiophenes: Design,synthesis and biological evaluation

2-amino-5-(3-fluoro-4-methoxyphenyl)thiophene-3-carbonitrile derivatives have been synthesized from 1-(3-fluoro-4-methoxyphenyl)ethanone, malononitrile, mild base, and sulfur powder using the Gewald method through a multistep reaction sequence. The structures of newly synthesized compounds were established on the basis of their elemental analyses, IR, ¹H NMR, ¹³C NMR, and mass spectral data, and then synthesized compounds were screened for their in vitro antimicrobial activity. Among them, derivatives 3b (thiphene), 3f (pyrazole), and 3d (halogen) showed good activity and remaining derivatives exhibited moderate activity.     

Bio-rational design of photosystem Ⅱ inhibitors (Ⅷ)——Molecular design, synthesis and inhibitory activity of acrylates (acrylamides)

Molecular modeling of acrylates (acrylamides) with D1 protein of Pisum sativum is presented. Studies show that the binding force mainly includes H-bond interaction, Van der Waals and π-ring stacking interaction. It was found that SER 268 in D1 protein might be an important binding site. It is important for high inhibitory activity of compounds whether an electronegative atom in alkyl of ester linkage could make H-bond interaction with SER 268 in D1 protein. Thus some new acrylates (acrylamides) were designed and synthesized, Bioassay indicated that these new compounds showed expected Hill reaction inhibitory activity.     

Aza-γ-carbolines and their benzannelated derivatives: methods of synthesis, chemical and biological properties (Review)*

Published data on methods of synthesis, chemical transformations, and biological properties of aza-γ-carbolines containing one or several additional nitrogen atoms in the phenylene fragment and their benzannelated analogs are reviewed.     

Organic synthesis and biological evaluation of novel “3 + 1” mixed ligands of technetium-99m Gabapentin as receptor imaging agents

This work focuses on the “3 + 1” mixed ligands of ^99mTc labeled Gabapentin as α2δ receptor imaging agents in the brain. Gabapentin 1-(aminomethyl)cyclohexanacetic acid as monodentate and two tridentates: tridentate A; 3-(2-imino-thiozolidin-4-one)-quinozoline-4-(3H)-one and tridentate B; N-(4-chlorophenyl)-2-imino-2H-chromene-3-Carbothioamide which were synthesized and characterized by infrared analysis (IR), ¹H nuclear magnetic resonance (NMR), and mass spectrum. ^99mTc-complexes were prepared by the “3 + 1” mixed ligand approach. The labeling conditions were optimized and the complexes was extracted by chloroform and purified by high performance liquid chromatography. ^99mTc-complexs were lipophilic and stable for at least 8–12 h at room temperature. The biodistribution of the ^99mTc-complexes was evaluated in mice. The brain uptake was 4.5% and 3.5% ID/g (percentage of the injected dose per gram) at 5 min, and the retention was 1.5% and 1.7% ID/g at 120 min for ^99mTc-complex A and ^99mTc-complex B, respectively.     

α-Spiro endoperoxides: synthesis and evaluation of their antimalarial activities

Endoperoxides belonging to the G-factor family, containing a spiroalkane moiety in the α position to the O-O bond, have been synthesized via an autoxidation reaction on the corresponding dienol precursors. Methylated derivatives in the peroxyhemiketal position have also been prepared. The in vitro antimalarial activities are reported. Fe(II)-induced reduction on endoperoxides 8 and 9 have been studied.     

Synthesis and biological evaluation of tetrahydroisoquinoline derivatives as potential multidrug resistance reversal agents in cancer

Tetrahydroisoquinoline derivatives were synthesized and their multidrug resistance reversal activities were evaluated in vitro. The results showed that some of the synthetic compounds had higher multidrug resistance （MDR） reversal activities than verapamil.     

Design,synthesis and biological evaluation of O-linked indoles as VEGFR-2 kinase inhibitors(Ⅰ)

Inhibition of VEGFR-2 signaling pathway has already become one of the most promising approaches for the treatment of cancer.In this study,we describe the design,synthesis,and biological evaluation of a series of O-linked indoles as potent inhibitors of VEGFR-2.Among these compounds,18 showed significant anti-angiogenesis activities via VEGFR-2 in enzymatic proliferation assays,with IC_(50) value of3.8 nmol/L Kinase selectivity profiling revealed that 18 was a multitargeted inhibitor,and it also exhibited good potency against VEGFR-1,PDCFR-α and β.     

Design,synthesis and biological evaluation of biphenylurea derivatives as VEGFR-2 kinase inhibitors(Ⅱ)

Inhibition of VEGFR-2 signaling pathway is one of the most promising approaches for the treatment of cancer. In this paper, we reported the design, synthesis, and biological evaluation of a series of biphenylurea derivatives as VEGFR-2 inhibitors. Among these compounds, 39 exhibited potent inhibitory activity against VEGFR-2 both in vitro and in vivo. The antiangiogenesis activity of 39 was further confirmed by both tube formation assay and chick chorioallantoic membrane assay.     

Total synthesis of (−)-synrotolide and the evaluation of its antiproliferative activity

The stereoselective synthesis of (−)-synrotolide was achieved in high overall yield from d-(−)-ribose and 3-butyn-1-ol. The pivotal step in this approach is the selective deprotection of the acetonide group in the presence of acetate groups using TiCl₄. Moreover, the biological activity of (−)-synrotolide was evaluated on HeLa, PANC 1, HepG2, and SK-N-SH cancer cell lines. The (−)-synrotolide selectively and potently inhibited the growth of PANC 1 cell line.     

Isolation, biological activity evaluation, structure elucidation, and total synthesis of eliamid: a novel complex i inhibitor

Eliamid is a secondary metabolite isolated from two bacterial strains. This molecule features a linear polyketide backbone terminated by a tetramic acid amide moiety. Among other biological activities, eliamid shows a high and specific cytostatic action on human lymphoma and cervix carcinoma cell lines. The 2,4-anti relative configuration of the C-2,C-4-dimethyl substituted amide fragment was assigned by means of Breit's rule. The absolute configuration of all stereocenters was determined by a combination of degradation methods, structural similarity analysis and total synthesis. The stereogenic centers were introduced by vinylogous Mukaiyama aldol reaction and two consecutive Myers alkylations. The use of pentafluorophenyl ester as acylation agent allowed the efficient formation of tetramic acid amide. The longest linear sequence in the synthesis consist of 13?steps and proceeds with 12?% overall yield. Differential spectroscopy experiments with beef heart submitochondrial particles established that eliamid is a potent inhibitor of the NADH-ubiquinone oxidoreductase complex. Additionally, biosynthesis of eliamid was investigated by feeding experiments with (13) C-labeled precursors.     

Developments in the synthesis of α,α-dibromoacetophenones and related compounds

Increasing demand of α,α-dibromoketones, as highly reactive and easy-to-handle precursors to carry out selective organic transformations, to synthesize heterocyclic compounds of therapeutic interest and lack of any compilation on this subject prompted us to assemble the methods available for their synthesis.