2-(2′-Pyridyl) benzimidazole derivatives and their urease inhibitory activity

Pyridyl-benzimidazole analogues 1–11 with variable substituent on phenyl ring of phenacyl moiety were synthesized and evaluated for their urease inhibitory activity. The compounds exhibited urease inhibition with IC₅₀ between 19.22 and 77.31 µM. Compounds 4 (IC₅₀ = 19.22 ± 0.49 µM) showed a urease inhibition comparable to thiourea (IC₅₀ = 21.00 ± 0.01 µM) and twofold more active than acetohydroxamic acid (IC₅₀ = 42.00 ± 1.26 µM) (standards), respectively. Moreover, compounds 5 (IC₅₀ = 21.55 ± 0.36 µM), 1 (IC₅₀ = 24.37 ± 0.41 µM), 7 (IC₅₀ = 25.44 ± 0.19 µM), 6 (IC₅₀ = 27.62 ± 0.25 µM), 3 (IC₅₀ = 31.32 ± 0.75 µM), 8 (40.88 ± 0.36 µM) and 9 (41.22 ± 0.42 µM) also exhibited excellent activities when compared to the standards. Compounds 2 (IC₅₀ = 65.46 ± 0.75 µM), 10 (68.99 ± 0.33 µM) and 11 (77.31 ± 0.51 µM) showed a moderate activity. The size of the substituents and their electron donating or withdrawing affects as well as their position on phenyl apparently modulates the enzyme inhibitory activity.     

Synthetic transformation of 6-Fluoroimidazo[1,2-a]Pyridine-3-carbaldehyde into 6-Fluoroimidazo[1,2-a]Pyridine-Oxazole Derivatives: In vitro urease inhibition and in silico study

PurposeUlcer is a serious disease that is caused due to different bacteria and over usage of various NSAIDs which caused to reduce the defensive system of stomach. Therefore, some novel series are needed to overcome these issues.MethodsOxazole-based imidazopyridine scaffolds (4a-p) were designed and synthesized by two step reaction protocol and then subjected to urease inhibition profile (in vitro). All the newly afforded analogs (4a-p) were found potent and demonstrated moderate to significant inhibition profile.ResultsParticularly, the analogs 4i (IC₅₀ = 5.68 ± 1.66 μM), 4o (IC₅₀ = 7.11 ± 1.24 μM), 4 g (IC₅₀ = 9.41 ± 1.19 μM) and 4 h (IC₅₀ = 10.45 ± 2.57 μM) were identified to be more potent than standard thiourea drug (IC₅₀ = 21.37 ± 1.76 μM). Additionally, the variety of spectroscopic tools such as ¹H NMR, ¹³C NMR and HREI-MS analysis were employed to confirm the precise structures of all the newly afforded analogs.DiscussionThe structure–activity relationship (SAR) studies showed that analogs possess the substitution either capable of furnishing strong HB like –OH or had strong EW nature such as -CF₃ & –NO₂ groups displayed superior inhibitory potentials than the standard thiourea drug. A good PLI (protein–ligand interaction) profile was shown by most active analogs when subjected to molecular study against corresponding target with key significant interactions such as pi-pi stacking, pi-pi T shaped and hydrogen bonding.     

Synthesis and evaluation of DPPH and anti-inflammatory activities of 2,6-bisbenzylidenecyclohexanone and pyrazoline derivatives

A series of thirty three 2,6-bisbenzylidenecyclohexanone and pyrazoline derivatives were synthesized and evaluated for inhibitory activities on IFN-γ/LPS-activated RAW 264.7 cells and DPPH radical scavenging activity. Compounds 8, 9, and 11a demonstrated significant NO inhibitory activity as compared to L-NAME and curcumin with IC₅₀ values of 6.68 ± 0.16, 6.09 ± 0.46, and 6.84 ± 0.12 μM, respectively. Apparently the suppression upon NO secretion was not due to cell death since the active compounds did not reduce the cell viability in close proximity to the IC₅₀ of NO inhibition. Overall, incorporation of pyrazoline ring as part of the linker chain improved cell viability compared to the 2,6-bisbenzylidenecyclohexanone derivatives. Meanwhile, compound 11 (IC₅₀ = 13.27 ± 1.78 μM) bearing ortho hydroxyls on the aromatic rings recorded the highest radical scavenging activity as compared with quercetin (IC₅₀ = 21.46 ± 0.85 μM).     

A cell-based assay for screening of antidotes to,and antivenom against Chironex fleckeri (box jellyfish) venom

IntroductionChironex fleckeri is a large box jellyfish that has been labelled the ‘most venomous animal’ in the world. We have recently shown that the primary effect of C. fleckeri venom in vivo is cardiovascular collapse. This study utilised a cell-based assay to examine the effects of C. fleckeri venom on the proliferation of a rat aortic smooth muscle cell line. In addition, the ability of CSL box jellyfish antivenom and/or various potential treatment strategies to neutralise the effects of the venom was examined.MethodsA7r5 cells were cultured in media containing venom. The effect of CSL box jellyfish antivenom (5 U/mL), CSL polyvalent snake antivenom (5 U/mL), lanthanum (5 µM), MgSO₄ (50 mM), verapamil (5 µM) or felodipine (5 µM) was examined. Cell viability was determined using a Cell titer 96 AQueous One Solution cell proliferation assay.ResultsIncubation of A7r5 cells with serially diluted venom (2–0.004 µg/mL) caused a concentration-dependent inhibition of cell proliferation with an IC₅₀ value of 0.056 µg/mL. This response was not affected by the absence of calcium or the presence of lanthanum in the media. Box jellyfish antivenom (5 U/mL) prevented the inhibition of cell proliferation caused by the venom. Verapamil (5 µM) had no significant effect on the inhibition. In contrast, felodipine (5 µM) or MgSO₄ (50 mM) potentiated the effects of the venom and partially negated the protective effect of the antivenom.DiscussionThis study displayed the ability to utilise a cell-based assay to determine the effects of C. fleckeri venom on vascular cell viability. It showed that CSL box jellyfish can neutralise the effects of the venom but only if added prior to the venom. In addition, potential adjunct therapies verapamil, felodipine and MgSO₄ were found to be ineffective, with felodipine and MgSO₄ potentiating the detrimental effects of the venom.     

Xanthine oxidase/tyrosinase inhibiting,antioxidant, and antifungal oxindole alkaloids from Isatis costata

Phytochemical investigations on the ethyl acetate soluble fraction of the whole plant of Isatis costata Linn. (Brassicaseae) led to the isolation of the oxindole alkaloids costinones A (1), B (2), isatinones A (3), B (4), indirubin (5), and trisindoline (6). Compounds 1–6 displayed significant to moderate inhibition against xanthine oxidase enzyme with IC₅₀ values ranging from 90.3?±?0.06 to 179.6?±?0.04 µM, whereas the standard inhibitor of xanthine oxidase (allopurinol) had an IC₅₀ value of 7.4?±?0.07 µM. Compounds 1 (IC₅₀ 7.21?±?0.05 µM), 2 (IC₅₀ 9.40?±?0.03 µM), 3 (IC₅₀ 11.51?±?0.07 µM), 4 (IC₅₀ 12.53?±?0.06 µM), 5 (IC₅₀ 14.29?±?0.09 µM), and 6 (IC₅₀ 17.34?±?0.04 µM) exhibited pronounced activities when compared with the standard tyrosinase inhibitor l-mimosine (IC₅₀ 3.70?±?0.03 µM), along with DPPH radical scavenging activity with IC₅₀ 226, 270, 300, 320, 401, and 431 µM, respectively. The crude extract and compounds 1, 2, 5, and 6 showed significant antifungal activity against Trichophyton schoen leinii, Aspergillus niger, Candida albicans, Trichophyton simii, and Macrophomina phaseolina.     

Synthetic polysulfane derivatives induce cell cycle arrest and apoptotic cell death in human hematopoietic cancer cells

Natural polysulfanes including diallyltrisulfide (DATS) and diallyltetrasulfide (DATTS) from garlic possess antimicrobial, chemopreventive and anticancer properties. However these compounds exhibit chemical instability and reduced solubility, which prevents their potential clinical applicability. We synthesized six DATS and DATTS derivatives, based on the polysulfane motif, expected to exhibit improved physical and chemical properties and verified their biological activity on human leukemia cells.We identified four novel cytotoxic compounds (IC₅₀ values: compound 1, 24.96 ± 12.37 μM; compound 2, 22.82 ± 4.20 μM; compound 3, 3.86 ± 1.64 μM and compound 5, 40.62 ± 10.07 μM, compared to DATTS: IC₅₀: 9.33 ± 3.86 μM). These polysulfanes possess excellent differential toxicity, as they did not affect proliferating mononuclear blood cells from healthy donors.We further demonstrated ability of active compounds to induce apoptosis in leukemia cells by analysis of nuclear fragmentation and of cleavage of effector and executioner caspases. Apoptosis was preceded by accumulation of cells in G2/M phase with a pro-metaphase-like nuclear pattern as well as microtubular alterations. Prolonged and persistent arrest of cancer cells in early mitosis by the benzyl derivative identifies this compound as the most stable and effective one for further mechanistic and in vivo studies.     

Design of semisynthetic derivatives of the Amaryllidaceae alkaloid ambelline and exploration of their in vitro cytotoxic activities

Ambelline, an alkaloid from the Amaryllidaceae family with a crinane-type skeleton, has not yet demonstrated any outstanding biological activity. However, its analogues prepared by derivatization of the C-11 hydroxyl group show different interesting effects. Continuing our earlier work, twelve novel aromatic esters were developed (10, 14, 16, 17, 22–25, 30–33) and studied, together with previously synthesized derivatives (2–9, 11–13, 15, 18–21, 26–29) in terms of their cytotoxic activity. The cytotoxic potential was determined on a panel of nine human cancer cell lines and one noncancerous cell line to characterize their biological activity spectrum. To describe and foresee the structure–activity relationship for further research, substances synthesized and described in our previous work were also included in this cytotoxicity study. The most significant activity was associated with analogues having methyl (10), methoxy (14–17), or ethoxy (18) substitution on the phenyl condensed to ambelline. However, the 4-chloro-3-nitrobenzoyl derivative (32) showed the most promising IC₅₀ values, ranging from 0.6 ± 0.1 µM to 9.9 ± 0.2 µM. In vitro cytotoxicity studies indicated the most potent antiproliferative activity of 32 in a dose-dependent and time-dependent manner. Besides, 32 was found to be effective in decreasing viability and triggering apoptosis of MOLT-4 T-lymphoblastic leukemia cells.     

Benzoxazole/benzothiazole‐derived VEGFR‐2 inhibitors: Design,synthesis, molecular docking,and anticancer evaluations

A novel series of benzoxazole/benzothiazole derivatives 4a–c – 11a–e were designed, synthesized, and evaluated for anticancer activity against HepG2, HCT‐116, and MCF‐7 cells. HCT‐116 was the most sensitive cell line to the influence of the new derivatives. In particular, compound 4c was found to be the most potent derivative against HepG2, HCT‐116, and MCF‐7 cells, with IC₅₀ values = 9.45 ± 0.8, 5.76 ± 0.4, and 7.36 ± 0.5 µM, respectively. Compounds 4b, 9f , and 9c showed the highest anticancer activities against HepG2 cells with IC₅₀ values of 9.97 ± 0.8, 9.99 ± 0.8, and 11.02 ± 1.0 µM, respectively, HCT‐116 cells with IC₅₀ values of 6.99 ± 0.5, 7.44 ± 0.4, and 8.15 ± 0.8 µM, respectively, and MCF‐7 cells with IC₅₀ values of 7.89 ± 0.7, 8.24 ± 0.7, and 9.32 ± 0.7 µM, respectively, in comparison with sorafenib as reference drug with IC₅₀ values of 9.18 ± 0.6, 5.47 ± 0.3, and 7.26 ± 0.3 µM, respectively. The most active compounds 4a–c, 9b,c,e,f,h , and 11c,e were further evaluated for their VEGFR‐2 inhibition. Compounds 4c and 4b potently inhibited VEGFR‐2 at IC₅₀ values of 0.12 ± 0.01 and 0.13 ± 0.02 µM, respectively, which are nearly equipotent to the sorafenib IC₅₀ value (0.10 ± 0.02 µM). Furthermore, molecular docking studies were performed for all synthesized compounds to assess their binding pattern and affinity toward the VEGFR‐2 active site.     

N-(3,4-dimethoxyphenethyl)-4-(6,7-dimethoxy-3,4-dihydroisoquinolin-2[1H]-yl)-6,7-dimethoxyquinazolin-2-amine (CP-100,356) as a “chemical knock-out equivalent” to assess the impact of efflux transporters on oral drug absorption in the rat

The utility of the diaminoquinazoline derivative CP-100,356 as an in vivo probe to selectively assess MDR1/BCRP-mediated drug efflux was examined in the rat. CP-100,356 was devoid of inhibition (IC₅₀ >50 µM) against major human P450 enzymes including P4503A4. In human MDR1-transfected MDCKII cells, CP-100,356 inhibited acetoxymethyl calcein (calcein-AM) uptake (IC₅₀ ～0.5 ± 0.07 µM) and digoxin transport (IC₅₀ ～1.2 ± 0.1 µM). Inhibition of prazosin transport (IC₅₀ ～1.5 ± 0.3 µM) in human BCRP-transfected MDCKII cells by CP-100,356 confirmed the dual MDR1/BCRP inhibitory properties. CP-100,356 was a weak inhibitor of OATP1B1 (IC₅₀ ～66 ± 1.1 µM) and was devoid of MRP2 inhibition (IC₅₀ >15 µM). In vivo inhibitory effects of CP-100,356 in rats were examined after coadministration with MDR1 substrate fexofenadine and dual MDR1/BCRP substrate prazosin. Coadministration with increasing doses of CP-100,356 resulted in dramatic increases in systemic exposure of fexofenadine (36- and 80-fold increase in C_max and AUC at a CP-100,356 dose of 24 mg/kg). Significant differences in prazosin pharmacokinetics were also discernible in CP-100,356-pretreated rats as reflected from a 2.6-fold increase in AUC. Coadministration of CP-100,356 and P4503A substrate midazolam did not result in elevations in systemic exposure of midazolam in the rat. The in vivo methodology should have utility in drug discovery in selective and facile assessment of the role of MDR1 and BCRP efflux transporters in oral absorption of new drug candidates. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:4914–4927, 2009     

Synthesis and screening of 2-(2-(4-substituted piperazine-1-yl)-5-phenylthiazol-4-yl)-3-aryl quinazolinone derivatives as anticancer agents

Synthesis of novel quinazolinone derivatives was performed from the reaction of N-benzoyl substituted piperazine-1-carbothioamide with 2-chloromethyl quinazolinone derivatives and screened for their in vitro cytotoxic activity by MTT assay. The cell lines used were NCI (human lung cancer cell), MCF 7 (Breast cancer cell), and HEK 293 (Normal epidermal kidney cell). Result of screening on cell line showed moderate to good anticancer activity for all the compounds. Compound 3d (IC₅₀ = 1.1 ± 0.03 μM) was found to be the most active compared to standard methotrexate (IC₅₀ = 2.20 ± 0.18 μM) and 5-florouracil (IC₅₀ = 2.30 ± 0.49 μM). Structure activity relationship of synthesized analogs suggested that the presence of NH linker with aryl moiety at the third position of quinazolinone ring was important for potent anticancer activity. Electron donating group on phenyl ring at the third position of quinazolinone ring gave better anticancer activity then unsubstituted phenyl and electron withdrawing group. Activity by substituted piperazine at 2nd position of thiazole linked with quinazolinone scaffold gave better activity in the order of H > CH₃ > CO–C₆H₅. Our findings may impart new direction to medicinal chemists and biochemists for further investigations of quinazolinone-thiazole containing anticancer agents.     

Bioevaluation of synthetic pyridones as dual inhibitors of α-amylase and α-glucosidase enzymes and potential antioxidants

Herein, a library of novel pyridone derivatives 1–34 was designed, synthesized, and evaluated for α-amylase and α-glucosidase inhibitory as well as antioxidant activities. Pyridone derivatives 1–34 were synthesized via a one-pot multi-component reaction of variously substituted aromatic aldehydes, acetophenone, ethyl cyanoacetate, and ammonium acetate in absolute ethanol. Synthetic compounds 1–34 were structurally characterized by different spectroscopic techniques. Most of the tested compounds showed more promising inhibition potential than the standard acarbose (IC₅₀ = 14.87 ± 0.16 µM) but compounds 13 and 12 were found to be the most potent compounds with IC₅₀ values of 9.20 ± 0.14 µM and 3.05 ± 0.18 µM against α-amylase and α-glucosidase enzymes, respectively. Compounds 1–34 also displayed moderate antioxidant potential in the range of IC₅₀ = 96.50 ± 0.45 to 189.98 ± 1.00 µM in comparison to the control butylated hydroxytoluene (BHT) (IC₅₀ = 66.50 ± 0.36 µM), in DPPH radical scavenging activities. Additionally, all synthetic derivatives were subjected to a molecular docking study to investigate the interaction details of compounds 1–34 (ligands) with the active site of enzymes (receptors). These results indicate that the newly synthesized pyridone class may serve as promising lead candidates for controlling diabetes mellitus and as antioxidants.     

Antidiabetic,antioxidant, molecular docking and HPTLC analysis of miquelianin isolated from Euphorbia schimperi C. Presl

The present study demonstrates the miquelianin or quercetin 3-O-glucuronide (compound 1) isolated from aerial parts of Euphorbia schimperi exhibited significant results for antioxidant and antidiabetic potential. The compound 1 along with kaempferol 3-O-glucuronide (compound 2) and quercetin 3-O-rhamnoside (compound 3) isolated from the same source were quantified by validated HPTLC method. Antioxidant activity was determined by chemical means in terms of ABTS radical cation and DPPH radical scavenging activity. Compound 1 showed significant scavenging activity in both ABTS and DPPH assays as compared to standard BHA. In ABTS method IC₅₀ values of compound 1 and standard BHA is found to be 58.90 ± 3.40 µg/mL and 28.70 ± 5.20 µg/mL respectively while in DPPH assay IC₅₀ values of Compound 1 and standard BHA is 47.20 ± 4.90 µg/mL and 34.50 ± 6.20 µg/mL respectively. Antidiabetic effect was studied through α-amylase and α-glucosidase inhibitory activity. The mechanistic approach through molecular modelling also support the strong binding sites of compound 1 which showed significant α-amylase and α-glucosidase inhibitory activities with IC₅₀ values 128.34 ± 12.30 and 89.20 ± 9.20 µg/mL respectively as compared to acarbose 64.20 ± 5.60 and 52.40 ± 4.60 µg/mL respectively. The results of validated RP-HPTLC analyses revealed the concentration of compound 1 found to be 16.39 µg/mg and for compound 2 and compound 3 as 3.92 and 14.98 µg/mg of dried extract, respectively.     

Antiproliferative effects of novel urea derivatives against human prostate and lung cancer cells; and their inhibition of β-glucuronidase activity

Twenty-one novel urea derivatives were synthesized and their structures characterized by mass, NMR, IR, and UV spectroscopy. These compounds were evaluated for their antiproliferative profile against human PC-3 (prostate) and NCI-H460 (lung) cancer cell lines. Among them, compound 21 N-(3-nitrophenyl)-N′-(1-phenylethyl)urea was found to be active against both PC-3 (IC₅₀ ± SEM: 20.13 ± 0.91 μM) and NCI-H460 (GI₅₀: 22 ± 2.6 μM) cell lines; hence has the potential to be further studied as anticancer agent. These compounds were also investigated for their ability to inhibit urease, β-glucuronidase, and phosphodiesterase enzymes. N-(2,6-Dimethylphenyl)-N′-(4′-nitrophenyl)urea (1) demonstrated 90 % inhibition of β-glucuronidase enzyme (IC₅₀ ± SEM: 3.38 ± 0.043 μM).     

Design,synthesis, molecular docking,and anticancer activity of benzoxazole derivatives as VEGFR‐2 inhibitors

Novel series of benzoxazole s 4 _a‐f ‐16 were designed, synthesized, and evaluated for anticancer activity against HepG2, HCT‐116, and MCF‐7 cells. HCT‐116 was the most sensitive cell line to the influence of the new derivatives. In particular, compound 5 _e was found to be the most potent against HepG2, HCT‐116, and MCF‐7 with IC₅₀ = 4.13 ± 0.2, 6.93 ± 0.3, and 8.67 ± 0.5 µM, respectively. Compounds 5 _c , 5 _f , 6 _b , 5 _d , and 6 _c showed the highest anticancer activities against HepG2 cells with IC₅₀ of 5.93 ± 0.2, 6.58 ± 0.4, 8.10 ± 0.7, 8.75 ± 0.7, and 9.95 ± 0.9 µM, respectively; HCT‐116 cells with IC₅₀ of 7.14 ± 0.4, 9.10 ± 0.8, 7.91 ± 0.6, 9.52 ± 0.5, and 12.48 ± 1.1 µM, respectively; and MCF‐7 cells with IC₅₀ of 8.93 ± 0.6, 10.11 ± 0.9, 12.31 ± 1.0, 9.95 ± 0.8, and 15.70 ± 1.4 µM, respectively, compared with sorafenib as a reference drug with IC₅₀ of 9.18 ± 0.6, 5.47 ± 0.3, and 7.26 ± 0.3 µM, respectively. The most active compounds 5 _c‐f and 6 _b,c were further evaluated for their vascular endothelial growth factor receptor‐2 (VEGFR‐2) inhibition. Compounds 5 _e and 5 _c potently inhibited VEGFR‐2 at lower IC₅₀ values of 0.07 ± 0.01 and 0.08 ± 0.01 µM, respectively, compared with sorafenib (IC₅₀ = 0.1 ± 0.02 µM). Compound 5 _f potently inhibited VEGFR‐2 at low IC₅₀ value (0.10 ± 0.02 µM) equipotent to sorafenib. Our design was based on the essential pharmacophoric features of the VEGFR‐2 inhibitor sorafenib. Molecular docking was performed for all compounds to assess their binding pattern and affinity toward the VEGFR‐2 active site.     

Promising selective MAO-B inhibition by sesamin,a lignan from Zanthoxylum flavum stems

Monoamine oxidase inhibition is an important therapeutic approach for various neurodegenerative disorders. Reversible MAO inhibitors selectively targeting only one isoform possess substantial merit in terms of safety, efficacy, and side effect profile. This study aimed to isolate the secondary metabolites of Zanthoxylum flavum stems and evaluate their recombinant human MAO inhibition, antimicrobial, and antiprotozoal activities. As a result, fourteen compounds were isolated and identified (nine of them were reported from Z. flavum for the first time). Compound 3 (sesamin) exhibited potent selective MAO-B inhibition (IC₅₀ value of 1.45 ± 0.05 µM) which reported herein for the first time. Compound 2 showed selective MAO-A inhibition activity, compound 5 exhibited good trypanocidal activity, and compound 7 displayed moderate antibacterial activity. The promising MAO-B inhibitory activity of sesamin provoked us to further explore the kinetic properties, the binding mode, and the underlying mechanism of MAO-B inhibition by this lignan. This detailed investigation substantiated a reversible binding and mixed MAO-B catalytic function inhibition via sesamin (K_i: 0.473 ± 0.076 μM). Selectivity and reversibility of sesamin on MAO-B provide exciting prerequisites for further in vivo investigation to confirm its therapeutic potentiality.     

Design,synthesis, docking,and anticancer evaluations of phthalazines as VEGFR-2 inhibitors

Twenty new N-substituted-4-phenylphthalazin-1-amine derivatives were designed, synthesized, and evaluated for their anticancer activities against HepG2, HCT-116, and MCF-7 cells as VEGFR-2 inhibitors. HCT-116 was the most sensitive cell line to the influence of the new derivatives. In particular, compound 7f was found to be the most potent derivative among all the tested compounds against the three cancer cell lines, with 50% inhibition concentration, IC₅₀ = 3.97, 4.83, and 4.58 µM, respectively, which is more potent than both sorafenib (IC₅₀ = 9.18, 5.47, and 7.26 µM, respectively) and doxorubicin (IC₅₀ = 7.94, 8.07, and 6.75 µM, respectively). Fifteen of the synthesized derivatives were selected to evaluate their inhibitory activities against VEGFR-2. Compound 7f was found to be the most potent derivative that inhibited VEGFR-2 at an IC₅₀ value of 0.08 µM, which is more potent than sorafenib (IC₅₀ = 0.10 µM). Compound 8c inhibited VEGFR-2 at an IC₅₀ value of 0.10 µM, which is equipotent to sorafenib. Moreover, compound 7a showed very good activity with IC₅₀ values of 0.11 µM, which is nearly equipotent to sorafenib. In addition, compounds 7d , 7c , and 7g possessed very good VEGFR-2-inhibitory activity, with IC₅₀ values of 0.14, 0.17, and 0.23 µM, respectively.     

5-(4-Methoxybenzylidene)thiazolidine-2,4-dione-derived VEGFR-2 inhibitors: Design,synthesis, molecular docking,and anticancer evaluations

A novel series of 5-(4-methoxybenzylidene)thiazolidine-2,4-dione derivatives, 5a–g and 7a–f , was designed, synthesized, and evaluated for their anticancer activity against HepG2, HCT116, and MCF-7 cells. HepG2 and HCT116 were the most sensitive cell lines to the influence of the new derivatives. In particular, compounds 7f , 7e , 7d , and 7c were found to be the most potent derivatives of all the tested compounds against the HepG2, HCT116, and MCF-7 cancer cell lines. Compound 7f (IC₅₀ = 6.19 ± 0.5, 5.47 ± 0.3, and 7.26 ± 0.3 µM, respectively) exhibited a higher activity than sorafenib (IC₅₀ = 9.18 ± 0.6, 8.37 ± 0.7, and 5.10 ± 0.4 µM, respectively) against HepG2 and MCF-7, cells but a lower activity against HCT116 cancer cells, respectively. Also, this compound displayed a higher activity than doxorubicin (IC₅₀ = 7.94 ± 0.6, 8.07 ± 0.8, and 6.75 ± 0.4 µM, respectively) against HepG2 and MCF-7 cells, but nearly the same activity against HCT116 cells, respectively. All derivatives, 5a–g and 7a–f , were evaluated for their inhibitory activities against vascular endothelial growth factor receptor-2 (VEGFR-2). Among them, compound 7f was found to be the most potent derivative that inhibited VEGFR-2 at an IC₅₀ value of 0.12 ± 0.02 µM, which is nearly the same as that of sorafenib (IC₅₀ = 0.10 ± 0.02 µM). Compounds 7e , 7d , 7c , and 7b exhibited the highest activity, with IC₅₀ values of 0.13 ± 0.02, 0.14 ± 0.02, 0.14 ± 0.02, and 0.18 ± 0.03 µM, respectively, which are more than the half of that of sorafenib. Furthermore, molecular docking was performed to investigate their binding mode and affinities toward the VEGFR-2 receptor. The data obtained from the docking studies highly correlated with those obtained from the biological screening.     

Efficacy of phenyl quinoline phenol derivatives as COX-2 inhibitors; an approach to emergent the small molecules as the anti-inflammatory and analgesic therapeutics

2-(4-phenylquinoline-2-yl)phenol derivatives (4a-l) with COX-2 enzyme inhibition, analgesic, anti-inflammatory and antipyretic potentials were executed and reported. From the in vitro COX-2 enzyme inhibition assay, compounds 4 h (IC₅₀ 0.026 µM) and 4j (IC₅₀ 0.102 µM) were found as most potent COX-2 inhibitors. Consequently, to get more insight into the binding mode with COX-2, compounds 4a-l were docked into the COX-2 (PDB ID: 1CX2) active site. In the Human Red Blood Cells (HRBC) membrane stabilization assay (in vitro anti-inflammatory), compounds 4f (IC₅₀ 0.064 µM) substituted with –OH (R¹) and –3Cl (R²), 4 h (IC₅₀ 0.021 µM), 4i (IC₅₀ 0.484 µg/ml) and 4j (IC₅₀ 0.092 µM) with –CHO containing alkanol and ether group at R1 and –4F, –4Br and –OMe at R2 (C2) were showed most potent anti-inflammatory activity. Eventually, acute toxicity studies revealed that 2-(4-phenylquinoline-2-yl)phenol derivatives (4a-l) are safe up to a toleration dose limit of 100 µg/kg body weight. In the Backer’s yeast intraperitoneal injection test, compounds 4f, 4 h and 4j produced significant (p < 0.05) antipyretic activity at 1, 1.5, 2 and 2.5 h, whereas test compound 4j and the reference drug indomethacin showed significant antipyretic activity throughout the observation period up to 2.5 h. Promising in vivo results obtained were correlated with the standard non-steroidal anti-inflammatory drugs and the compounds 4f, 4 h, 4i, 4j, and 4 l were efficiently identified as therapeutically potent/fortune moieties as non-steroidal anti-inflammatory agents/analgesics. At the end, ulcerogenic study result ensured that the tested 2-(4-phenylquinoline-2-yl)phenol derivatives created no side-effect.     

Synthesis,structural elucidation and bioevaluation of 4-amino-1,2,4-triazole-3-thione’s Schiff base derivatives

In this study, a series of ten triazole Schiff base derivatives 6a–j were synthesized through microwave assisted imine formation by reacting substituted amino triazole 5 with different substituted aldehydes. All the synthesized compounds were evaluated for their inhibitory activity against mushroom tyrosinase. Two of the compounds 6a and 6b among the series 6a–j were found to be highly potent tyrosinase inhibitors with IC₅₀ values of 10.09 ± 1.03 and 6.23 ± 0.85 µM, respectively, which were even higher than that of the reference inhibitor kojic acid (IC₅₀ = 16.6 ± 2.8 µM). Compounds 6e and 6f with IC₅₀ values of 20.27 ± 2.78 and 26.02 ± 4.14 µM, respectively, were comparable to the reference inhibitor, and the remaining compounds had a moderate inhibitory activity against mushroom tyrosinase. The most potent compounds (6a, 6b) were used in the kinetic and optical analyses. The inhibition kinetics analyzed with Lineweaver–Burk plots revealed that both compounds 6a and 6b were non-competitive inhibitors of tyrosinase with inhibition constant values of 0.023 and 0.022 mM, respectively.     

The α-glucosidase inhibitory activity of avicularin and 4-O-methyl gallic acid isolated from Syzygium myrtifolium leaves

Diabetes Mellitus is the main cause of death on a global scale. In 2019, there were 463 million people with diabetes, and WHO predicts that by 2030, there will be 578 million. As an antidiabetic agent, α-glucosidase inhibitors are one of the methods employed to reduce the prevalence of diabetes. Diabetes is traditionally treated with Syzygium as a primary material, medicine, fruit, ornamental plant, and source of carpentry. This investigation aimed to examine the inhibitory effect of seven species of Syzygium against α-glucosidase enzyme using an in vitro assay and isolate active substances and ascertain their concentrations in each sample. As a solvent, ethanol was used in maceration to extract the substance. Afterward, the extract underwent a series of fractionation techniques, including liquid–liquid extraction, vacuum liquid chromatography, column chromatography, and preparative Thin Layer Chromatography (TLC) for purification and isolation. The compound's structures were elucidated using TLC, UV–Visible spectrophotometry, and nuclear magnetic resonance (NMR) spectroscopy. Based on concentrations of 100 and 200 µg/mL, Syzygium myrtifolium exhibited the most significant inhibitory effect, followed by other species of Syzygium. The proportion of ethyl acetate had the strongest activity (IC₅₀ 0.40 ± 0.02 µg/mL) contrasted to positive control acarbose (IC₅₀ 55.39 ± 0.67 g/mL) and quercitrin (IC₅₀ 6.47 ± 0.40 µg/mL). Avicularin and 4-O-methyl gallic acid were discovered in the ethyl acetate fraction of Syzygium myrtifolium with IC₅₀ values of 17.05 ± 0.75 µg/mL and 25.19 ± 0.21 µg/mL, respectively. As α-glucosidase inhibitory, the results of this study indicate Syzygium myrtifolium can be used as a dietary supplement to manage hyperglycemia.