Novel diphenylamine 2,4'-dicarboxamide based azoles as potential epidermal growth factor receptor inhibitors: synthesis and biological activity

Several hybrid molecules of diphenylamine-2,4'-dicarboxamide with various azolidinones and related heterocyclic rings have been synthesized and explored as epidermal growth factor receptor (EGFR) kinase inhibitors. Most of them displayed promising in vitro tyrosine kinase inhibition as well as potent cellular antiproliferative activity in the EGFR over-expressing breast cancer cell line (MCF-7). Compounds 12b and 13b that exhibited the highest inhibition in the kinase assay (89, 81% inhibition at 10 μM, respectively), showed potent antiproliferative effect against MCF-7 tumor cell line (IC(50) 1.04, 0.91 μM respectively). Molecular docking studies revealed that these compounds can bind to ATP binding site of the EGFR kinase domain and were involved in H-bonding with Met 793, in analogy to the known EGFR tyrosine kinase inhibitors. Moreover, compounds 15a-c possessed profound antitumor activity (IC(50) 0.59-0.73 μM) and significant EGFR-TK inhibition, making them of particular interest. In summary, the newly synthesized compounds provide promising new lead for the future design and development of anticancer agents of potential EGFR-TK inhibitory activity.     

Novel pyrazole-biphenyl-carboxamides for SARS-CoV2 entry-level restriction and microbial infections

Microbial diseases including viral infection are big issues globally. Effective medicinal discovery for them is the need for the day. In this study, we report pyrazole-biphenyl-carboxamides ( 4a-l ) validated for their SARS-CoV2 entry-level restriction effect over studying the protein–protein interaction of SARS-CoV2 with human ACE protein. Their extended antimicrobial properties were also evaluated. Online and offline software tools predicted MD simulation and ADMET druggability in silico. The antimicrobial efficacy of all compounds was also evaluated against Gram+^ve Streptococcus pneumoniae (MTCC 1936), Staphylococcus aureus (MTCC 737) and Gram-^ve Escherichia coli (MTCC 443), Pseudomonas aeruginosa (MTCC 424) (bacteria). In the results, compounds 4g and 4i were evenly active against both bacteria at a low concentration range (MIC: 1.00 to 9.5 μg/mL) and displayed lesser toxicity to tested mammalian cells (EC₁₀₀ = 75 μg/mL). Furthermore, it was able to kill metabolically inactive bacterial cells and eradicate established biofilms of Methicillin-resistant Staphylococcus aureus (MRSA). Both the compounds inhibited DNA gyrase well with an IC₅₀ 0.25 μM (96% relative activity) and 0.52 μM (97% relative activity) respectively. Compounds ( 4a-l ) showed restrictive efficiency of SARS-CoV2 spike protein (SC2SP) and human angiotensin-converting enzyme 2 (hACE2) entry-level association in COVID-19 in silico. To assess this ability, firstly, we identified the crucial amino acid residues involved in the interface of SARS-CoV-2 and hACE2 virtually. We recognized the ability of 4a-l binding to the binding interface to SARS-CoV2; thus, the interaction of SC2SP-hACE2 was effectively inhibited.     

Antimicrobial phenalenone derivatives from the marine-derived fungus Coniothyrium cereale

The marine-derived fungus Coniothyrium cereale was isolated from the green alga Enteromorpha sp. and found to produce the new phenalenone derivatives 1-7 as well as the known compounds lactone 8, (-) sclerodin (9), lamellicolic anhydride (10), (-) scleroderolide (11), and (-) sclerodione (12). The structures of these closely related compounds were established from extensive spectroscopic investigations on the basis of one and two dimensional NMR spectroscopic studies ((1)H, (13)C, COSY, NOESY, HSQC and HMBC) as well as mass spectrometric analysis (LC/MS, HREIMS and HRESIMS), UV and IR spectra. Compounds 5 and 11 showed the same antimicrobial activity toward Staphylococcus aureus SG 511 with an MIC value of 24 μM. The presence of a diketo-lactone ring as in compounds 5 and 11 was found to be essential for this activity. In agar diffusion assays with Mycobacterium phlei considerable inhibition zones were observed for compounds 2, 4 and 7. Compounds 1, 5 and 9 showed potent inhibition of human leukocyte elastase (HLE) with IC(50) values of 7.2, 13.3 and 10.9 μM, respectively.     

Synthesis and bioactivity evaluation of eugenol hybrids obtained by Mannich and 1,3 dipolar cycloaddition reactions

Design, synthesis, and bioactivity evaluation of novel mannich bases ( 2a-2j ) and triazole-chalcone derivatives ( 7a-7k ) of Eugenol 1 were reported. Among all the derivatives tested for antiproliferative activity, di-amine manich derivative 2b (32.92 μM), and 4-methoxy chalcone triazole derivative 7d (33.05 μM) significantly inhibited HepG2 cell lines when compared to the standard doxorubicin (37.29 μM). Whereas most of the compounds such as diethylamine 2a (17.75 μM), (aminomethyl) methane diamine 2b (17.02 μM), and bis (chloromethyl) amine 2c (20.12 μM) showed moderate to better inhibition towards MCF-7 cell lines. The synthesized analogues were also tested for antidiabetic and antiobesity potentials. Compounds 2f (55.50%), 2c (54.34%), 7g (55.5%), and 2a (55.5%) have shown moderate inhibitory potentials toward intestinal α-glucosidase enzyme when compared to the standard Acarbose (72.86%). Likewise, compounds 7d (82.95%), 7f (76.19%), 7g (74.81%), 7e (74.81%), and 2g (72.50%) have shown significant to moderate inhibitory potentials toward Pancreatic lipase enzyme when compared to the standard orlistat (91.10%). ROS induces life-threatening diseases like diabetes, cancer, etc., and antioxidants play a major role in controlling their production. Compounds 2c (99.81%), 2i (99.80%), 2d (99.26%), 2g (98.79%), and 2f (98.42%) have shown significant antioxidant profiles in ABTS assay when compared to the standard Trolox (99.07%). Further, In silico Molecular docking and pharmacokinetic screening of the eugenol derivatives complemented the in vitro results indicating the drug likeness of the obtained active compounds.     

Phenothiazine-based chalcones as potential dual-target inhibitors toward cholinesterases (AChE,BuChE) and monoamine oxidases (MAO-A,MAO-B)

Chalcones targeting neurodegenerative diseases have been known as attractive structures in drug design and discovery. In this study, phenothiazine-based chalcones as ChEs and MAOs inhibitors were designed and synthesized via base-catalyzed Claisen-Schmidt condensation, and chemical structures of the compounds were elucidated by NMRs and HRMS. Compounds 3 and 9 showed promising inhibition potency against AChE enzyme with IC₅₀ values of 0.221 μM and 0.053 μM while compound 9 displayed remarkable inhibition potency toward MAO-B enzyme with IC₅₀ value of 0.048 μM. Compound 9 , as a dual-target inhibitor, selectively inhibited AChE and MAO-B enzymes. This promising behavior is an advantage for the compound since MAO-B and AChE inhibition have a role in Alzheimer's disease. Fused tricyclic ring systems such as phenothiazine incorporated with chalcone moiety being multitargeting ligands may help scientists for the rational design of novel lead compounds targeting neurodegenerative illnesses.     

4-(N-乙酰氨基)-3-(4-芳基噻唑-2-氨基)苯甲酸乙酯的合成与生物活性

以3-氨基-4-乙酰氨基苯甲酸乙酯为原料设计合成了18种4-(N-乙酰氨基)-3-(4-芳基噻唑-2-基)-苯甲酸乙酯新化合物.化合物结构经质谱,元素分析,1H NMR和13C NMR确证.生物活性实验结果表明,化合物3d,3h,3p(40μg/mL)对神经氨酸酶(NA)的抑制率分别为36.02%,33.40%,42.05%;化合物3g,3h(500mg/L)对纹枯病菌的抑制率为50%.     

Sesquiterpenes from the leaves of Nicotiana tabacum and their anti-tobacco mosaic virus activity

In searching for more bioactive compounds, phytochemical investigations on the acetone extract of the leaves of Nicotiana tabacum resulted in the isolation of two new sesquiterpenes, nicosesquiterpene A and B(1 and 2), along with four known sesquiterpene derivatives(3–6). Structural elucidation of 1 and 2 was performed by spectral methods, such as HRMS, IR, UV, 1D and 2D NMR spectroscopy. Compounds 1 and 2are the first naturally occurring pterosin-type sesquiterpene bearing an isopropyl moiety. Compounds1–6 were also evaluated for their anti-tobacco mosaic virus(anti-TMV) activity. The results showed that compounds 1 and 2 exhibited high anti-TMV activity with inhibition rates of 36.7% and 45.6%,respectively, which is higher than that of positive control. The other compounds also showed potential activity with inhibition rates in the range of 22.7%–29.2%.     

Novel 3‐benzoyl‐2‐piperazinylquinoxaline derivatives as potential antitumor agents

A series of new benzoylquinoxaline derivatives ( 7‐26 ) was synthesized and evaluated for antitumor activity against a panel of 60 human cell lines at the NCI of Bethesda. Among the compounds which have passed the preliminary screening, compound 23 exhibited the best profile and growth inhibition activity at 100 ‐ 10 μM. The compounds were then tested towards a folate‐dependent enzymes bio‐library including Thymidylate synthases enzymes and human Dihydrofolate reductase at 10 μM. The most of compounds exhibited a moderate inhibitory activity towards all or some of the enzymes tested with detectable inhibition constants (K_i) values in the range of 0.6‐70 μM. Compounds 21, 23, 24 showed K_i in the range of 10‐38 μM against both hDHFR and hTS.     

Butylated hydroxytoluene analogs: synthesis and evaluation of their multipotent antioxidant activities

A computer-aided predictions of antioxidant activities were performed with the Prediction Activity Spectra of Substances (PASS) program. Antioxidant activity of compounds 1, 3, 4 and 5 were studied using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and lipid peroxidation assays to verify the predictions obtained by the PASS program. Compounds 3 and 5 showed more inhibition of DPPH stable free radical at 10?? M than the well-known standard antioxidant, butylated hydroxytoluene (BHT). Compound 5 exhibited promising in vitro inhibition of Fe2?-induced lipid peroxidation of the essential egg yolk as a lipid-rich medium (83.99%, IC?? 16.07 ± 3.51 μM/mL) compared to α-tocopherol (α-TOH, 84.6%, IC?? 5.6 ± 1.09 μM/mL). The parameters for drug-likeness of these BHT analogues were also evaluated according to the Lipinski’s “rule-of-five” (RO5). All the BHT analogues were found to violate one of the Lipinski’s parameters (LogP > 5), even though they have been found to be soluble in protic solvents. The predictive polar surface area (PSA) and absorption percent (% ABS) data allow us to conclude that they could have a good capacity for penetrating cell membranes. Therefore, one can propose these new multipotent antioxidants (MPAOs) as potential antioxidants for tackling oxidative stress and lipid peroxidation processes.     

A UPLC-DAD-Based Bio-Screening Assay for the Evaluation of the Angiotensin Converting Enzyme Inhibitory Potential of Plant Extracts and Compounds: Pyrroquinazoline Alkaloids from Adhatoda vasica as a Case Study

Angiotensin converting enzyme (ACE) plays a crucial role in regulating blood pressure in the human body. Identification of potential ACE inhibitors from medicinal plants supported the idea of repurposing these medicinal plants against hypertension. A method based on ultra-performance liquid chromatography (UPLC) coupled with a diode array detector (DAD) was used for the rapid screening of plant extracts and purified compounds to determine their ACE inhibitory activity. Hippuryl-histidiyl-leucine (HHL) was used as a substrate, which is converted into hippuric acid (HA) by the action of ACE. A calibration curve of the substrate HHL was developed with the linear regression 0.999. The limits of detection and quantification of this method were found to be 0.134 and 0.4061 mM, respectively. Different parameters of ACE inhibitory assay were optimized, including concentration, incubation time and temperature. The ACE inhibition potential of Adhatoda vasica (methanolic-aqueous extract) and its isolated pyrroquinazoline alkaloids, vasicinol (1), vasicine (2) and vasicinone (3) was evaluated. Compounds 1–3 were characterized by various spectroscopic techniques. The IC₅₀ values of vasicinol (1), vasicine (2) and vasicinone (3) were found to be 6.45, 2.60 and 13.49 mM, respectively. Molecular docking studies of compounds 1–3 were also performed. Among these compounds, vasicinol (1) binds as effectively as captopril, a standard drug of ACE inhibition.     

Benzylidene-bis-(4-hydroxycoumarin) and benzopyrano-coumarin derivatives: synthesis, ¹H/¹³C-NMR conformational and X-ray crystal structure studies and in vitro antiviral activity evaluations

We report on the synthesis of 4-hydroxycoumarin dimers 1-15 bearing an aryl substituent on the central linker and fused benzopyranocoumarin derivatives 16-20 and on their in vitro broad anti-DNA and RNA virus activity evaluations. The chemical identities and structure of compounds 1-20 were deduced from their homo- and heteronuclear NMR measurements whereas the conformational properties of 5, 14 and 20 were assessed by the use of 1D difference NOE enhancements. Unequivocal proof of the stereostructure of compounds 7, 9, 16 and 18 was obtained by single crystal X-ray diffraction method. The X-ray crystal structure analysis revealed that two 4-hydroxycoumarin moieties in the 4-trifluoromethylphenyl- and 2-nitrophenyl derivatives (compounds 7 and 9, respectively) are intramolecularly hydrogen-bonded between hydroxyl and carbonyl oxygen atoms. Consequently, the compounds 7 and 9 adopt conformations in which two 4-hydroxy-coumarin moieties are anti-disposed. Antiviral activity evaluation results indicated that the 4-bromobenzylidene derivative of bis-(4-hydroxycoumarin) (compound 3) possesses inhibitory activity against HSV-1 (KOS), HSV-2 (G), vaccinia virus and HSV-1 TK? KOS (ACVr) at a concentration of 9-12 μM and at a minimum cytotoxic concentration (MCC) greater than 20 μM. Compounds 4-6, 8, and 20 were active against feline herpes virus (50% effective concentration, EC?? = 5-8.1 μM), that is at a 4-7-fold lower concentration than the MCC.     

Oxygenated hexylitaconates from a marine sponge-derived fungus Penicillium sp

In the course of our search for bioactive metabolites from marine organisms, new hexylitaconic acid derivatives (1-4), along with (3S)-hexylitaconic acid (5), were isolated from a sponge-derived fungus Penicillium sp. Based on the NMR and MS data, the structures of compounds 1-4 were defined as α,β-dicarboxylic acid derivatives, such as hexylitaconic acid and tensyuic acids which were previously reported as metabolite of Aspergillus niger, Penicillium striatisporum, or Apiospora montagnei. The isolated compounds were evaluated for cytotoxicity against a panel of five human solid tumor cell lines, and for anti-inflammatory activity gauged by their inhibitory effects on the production of major pro-inflammatory mediators (nitric oxide (NO), interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-1β) in murine macrophage cells. Compounds 1 and 4 showed weak inhibition of IL-1β production at the concentration of 200 μM.     

Synthesis and Urease Inhibition Studies of Barbituric and Thiobarbituric Acid Derived Sulphonamides

Various novel barbituric and thiobarbituric acid derived sulphonamides were synthesized in excellent yield via three components single pot reaction; and these were screened for in vitro urease inhibition studies against jack bean urease. The compounds 1‐7 were found to exhibit a low to moderate activity whereas compounds 8‐14 showed a significant activity (88.3‐99.9% inhibition determined at 500 μM concentration). Structures of the synthesized compounds were confirmed by ¹H‐NMR, ¹³C‐NMR, mass spectrometry and elemental analysis data.     

Benzothiazole and Chromone Derivatives as Potential ATR Kinase Inhibitors and Anticancer Agents

Despite extensive studies and the great variety of existing anticancer agents, cancer treatment remains an aggravating and challenging problem. Therefore, the development of novel anticancer drugs with a better therapeutic profile and fewer side effects to combat this persistent disease is still necessary. In this study, we report a novel series of benzothiazole and chromone derivatives that were synthesized and evaluated for their anticancer activity as an inhibitor of ATR kinase, a master regulator of the DDR pathway. The cell viability of a set of 25 compounds was performed using MTT assay in HCT116 and HeLa cell lines, involving 72 h incubation of the compounds at a final concentration of 10 µM. Cells incubated with compounds 2c, 7h and 7l were found to show viability ≤50%, and were taken forward for dose–response studies. Among the tested compounds, three of them (2c, 7h and 7l) showed higher potency, with compound 7l exhibiting the best IC₅₀ values in both the cell lines. Compounds 2c and 7l were found to be equally cytotoxic towards both the cell lines, namely, HCT116 and HeLa, while compound 7h showed better cytotoxicity towards HeLa cell line. For these three compounds, an immunoblot assay was carried out in order to analyze the inhibition of phosphorylation of Chk1 at Ser 317 in HeLa and HCT116 cells. Compound 7h showed inhibition of pChk1 at Ser 317 in HeLa cells at a concentration of 3.995 µM. Further analysis for Chk1 and pChk1 expression was carried out in Hela cells by treatment against all the three compounds at a range of concentrations of 2, 5 and 10 µM, wherein compound 7h showed Chk1 inhibition at 2 and 5 µM, while pChk1 expression was observed for compound 7l at a concentration of 5 µM. To support the results, the binding interactions of the compounds with the ATR kinase domain was studied through molecular docking, wherein compounds 2c, 7h and 7l showed binding interactions similar to those of Torin2, a known mTOR/ATR inhibitor. Further studies on this set of molecules is in progress for their specificity towards the ATR pathway.     

The structure of a new cardenolide diglycoside and the biological activities of eleven cardenolide diglycosides from Nerium oleander

A new cardenolide diglycoside (1) was isolated from Nerium oleander together with ten known cardenolide diglycosides 2-11. The structure of compound 1 was established on the basis of their spectroscopic data. The in vitro anti-inflammatory activity of compounds 1-11 was examined on the basis of inhibitory activity against the induction of the intercellular adhesion molecule-1 (ICAM-1). Compounds 2-5 were active at an IC(50) value of less than 0.8 μM. The cytotoxicity of compounds 1-11 was evaluated against three human cell lines normal human fibroblast cells (WI-38), malignant tumor cells induced from WI-38 (VA-13), and human liver tumor cells (HepG2). Compound 3 was active toward VA-13 cells, and compounds 2-5 were active toward HepG2 cells at IC(50) values of less than 1.3 μM. The multidrug resistance (MDR)-reversal activity of compounds 1-11 was evaluated on the basis of the amount of calcein in MDR human ovarian cancer 2780AD cells in the presence of each compound. Compounds 1 and 8 showed moderate effects on calcein accumulation.     

含6-氟喹唑啉片段的新型1,3,4-噁(噻)二唑类衍生物的合成及抗菌活性研究

为寻找高效农用抗菌先导化合物,通过活性亚结构拼接法设计合成了50个含6-氟喹唑啉片段的新型1,3,4-噁(噻)二唑类衍生物6 a?6 y和8a?8y,其结构经¹H NMR、¹³C NMR和HRMS手段进行了表征,且化合物6i和8x的结构最终由X射线单晶衍射法加以确认.初步抗菌测试表明,部分化合物表现出较好的体外抗真菌活性.在50μg/m L浓度下,化合物6b、6d、6t、6v和6x对小麦赤霉病菌的抑制率分别为58%、58%、55%、63%和60%,化合物6 v和8v对苹果腐烂病菌的抑制率分别为71%和64%,化合物6 v对油菜炭疽病菌的抑制率为72%,它们均优于对照药剂噁霉灵(分别为51%、61%和70%).此外,部分化合物在100μg/m L浓度下也表现出一定的体外抗细菌活性.     

Strong inhibition of celastrol towards UDP-glucuronosyl transferase (UGT) 1A6 and 2B7 indicating potential risk of UGT-based herb-drug interaction

Celastrol, a quinone methide triterpene isolated from Tripterygium wilfordii Hook F., has various biochemical and pharmacological activities, and is now being developed as a promising anti-tumor agent. Inhibitory activity of compounds towards UDP-glucuronosyltransferase (UGT) is an important cause of clinical drug-drug interactions and herb-drug interactions. The aim of the present study is to investigate the inhibition of celastrol towards two important UDP-glucuronosyltransferase (UGT) isoforms UGT1A6 and UGT2B7. Recombinant UGT isoforms and non-specific substrate 4-methylumbelliferone (4-MU) were used. The results showed that celastrol strongly inhibited the UGT1A6 and 2B7-mediated 4-MU glucuronidation reaction, with 0.9 ± 0.1% and 1.8 ± 0.2% residual 4-MU glucuronidation activity at 100 μM of celastrol, respectively. Furthermore, inhibition kinetic study (Dixon plot and Lineweaver-Burk plot) demonstrated that celastrol noncompetitively inhibited the UGT1A1-mediated 4-MU glucuronidation, and competitively inhibited UGT2B7-catalyzed 4-MU glucuronidation. The inhibition kinetic parameters (Ki) were calculated to be 0.49 μM and 0.045 μM for UGT1A6 and UGT2B7, respectively. At the therapeutic concentration of celastrol for anti-tumor utilization, the possibility of celastrol-drug interaction and celastrol-containing herbs-drug interaction were strongly indicated. However, given the complicated nature of herbs, these results should be viewed with more caution.     

Synthesis,Crystal Structure and Biological Activites of Rotenone O-Alkyl Oximes

A series of rotenone O-alkyl oxime derivatives was designed and synthesized. Their structures were confirmed by elemental analyses, Fourier transform infrared(FTIR) and ¹H NMR spectral studies, and the typical crystal structure of rotenone O-ethyl oxime(3b) was determined by X-ray diffraction. The preliminary biological activities of the new compounds were evaluated. The results of bioassays indicate that the title compounds exhibit moderate insecticidal and bactericidal activities. Among the synthesized compounds, compound 3q exhibited 90.0% mortality against M. separata at 1000 μg/mL. Compounds 3b and 3g exhibited both 90.0% inhibition rate against R. solani at 500 μg/mL, respectively.     

Nitrile-Containing Fischerindoles from the Cultured Cyanobacterium Fischerella sp

Chemical investigation of the cultured cyanobacterium Fischerella sp. (SAG strain number 46.79) led to the isolation of four nitrile-containing indole alkaloids, namely 12-epi-fischerindole I nitrile (1), deschloro 12-epi-fischerindole I nitrile (2), 12-epi-fischerindole W nitrile (3), and deschloro 12-epi-fischerindole W nitrile (4) along with a known metabolite hapalosin. The structures were determined by detailed spectroscopic analyses on the basis of 1D and 2D NMR and HRESIMS data. All isolates were evaluated for cytotoxicity against human cancer cells and for 20S proteasome inhibition. Deschloro 12-epi-fischerindole I nitrile (2) was found to be weakly cytotoxic against HT-29 cells with an ED(50) value of 23 μM. Hapalosin showed weak cytotoxicity against HT-29 and MCF-7 cells with ED(50) values of 22 and 27 μM, respectively, as well as moderate 20S proteasome inhibition with an IC(50) value of 12 μM. Compounds 1-4 all contain a nitrile moiety instead of the isonitrile found in all fischerindoles reported to date. Compounds 3 and 4 also display a new carbon skeleton, in which a six-membered ring replaces the five-membered ring normally found in fischerindole-type alkaloids.     

酰胺类KARI酶抑制剂的设计、合成和生物活性

以分子对接法进行MDL/ACD三维数据库搜寻所得到的大量结构信息为指导, 从中选取部分酰胺类小分子进行化学合成和结构表征. 生物活性测试结果表明, 设计合成的8个酰胺类化合物在200 μg/mL浓度下对水稻KARI酶具有不同程度的抑制活性, 化合物1和6的抑制率可达到57.4%和48.1%. 部分化合物在100 μg/mL浓度下对双子叶植物油菜的胚根和单子叶植物稗草的茎叶的抑制活性较为显著, 化合物1和6对油菜胚根生长抑制率分别为52.0%和72.6%, 其与KARI酶体外(in vitro)抑制活性具有一定的相关性. 这些酰胺类化合物可作为KARI酶抑制剂为后续分子设计提供借鉴.