Synthesis and molecular docking study of α-aminophosphonates as potential multi-targeting antibacterial agents

Antibacterial compounds that reduce extracellular polymeric substances (EPS) are needed to avoid bacterial biofilms in water pipelines. Herein, green one-pot synthesis of α-aminophosphonates (α-Amps) [A-G] was achieved by using ionic liquid (IL) as a Lewis acid catalyst. The synthesized α-Amp analogues were tested against different bacteria such as Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. The representative [B] analogue showed an efficient antibacterial effect with MIC values of 3.13 μg/mL for E. coli, P. aeruginosa, and 6.25 μg/mL for B. subtilis. Additionally, a strong ability to eliminate the mature bacterial biofilm, with super-MIC values of 12.5 μg/mL for E. coli, P. aeruginosa, and 25 μg/mL for B. subtilis. Moreover, bacterial cell disruption by ROS formation was also tested, and the compound [B] revealed the highest ROS level compared to other compounds and the control, and efficiently destroyed the extracellular polymeric substances (EPS). The docking study confirmed strong interactions between [B] analogue and protein structures with a binding affinity of -6.65 kCal/mol for the lyase protein of gram-positive bacteria and -6.46 kCal/mol for DNA gyrase of gram-negative bacteria. The results showed that α-Amps moiety is a promising candidate for developing novel antibacterial and anti-biofilm agents for clean water supply.

Antimicrobial Evaluation of Sulfonamides after Coupling with Thienopyrimidine Coplanar Structure

This work describes the design and synthesis of three series of hybrids of thienopyrimidines and sulfonamides. Dihydrofolate reductase enzyme was selected as a target for the in-silico screening of the synthesized thienopyrimidine-sulfonamide hybrid as an antibacterial, while squalene epoxidase was selected as an antifungal target protein. All screened compounds showed promising binding affinity ranges, with perfect fitting not exceeding 1.9 Å. The synthesized compounds were tested for their antimicrobial activity using agar well diffusion and minimum inhibitory concentration tests against six bacterial strains in addition to two Candida strains. Compounds 8iii and 12ii showed varying degrees of inhibition against Staphylococcus aureus and Escherichia coli bacterial strains, whereas the best antifungal activity against Candida was displayed by compound 8iii. Compound 12ii, the cyclohexathienopyrimidine coupled with sulfadiazine at position 3, has the best antibacterial activity, which is consistent with molecular docking results at the active site of the oxidoreductase protein. Interestingly, compound 12ii also has the highest docking binding energy at the antifungal squalene epoxidase active site. Investigating the physicochemical properties of the synthesized hybrids revealed their high tolerability with cell membranes, and moderate to poor oral bioavailability, and that all are drug-like candidates, among which 4i, the cyclohexathieno[2,3-d] pyrimidine core with sulphaguanidine incorporated at position 4, recorded the best score (1.58).

Synthesis and in-vitro anti-proliferative with antimicrobial activity of new coumarin containing heterocycles hybrids

A series of new coumarin-N-heterocyclic hybrids, coumarin-quinolines 7a-e, coumarin-acridines 10b,c and coumarin-neocryptolepines 13b,c were synthesized and evaluated for their anticancer and antimicrobial activities. The structures of all synthesized hybrids were confirmed by FT-IR, 1H-NMR, 13C-NMR, and MS spectrometry. The anti-proliferative activity of hybrids 7a-e, 10c and 13c were bio-evaluated using MTT-assay against colon (CaCo-2), lung (A549), breast (MDA-MB-231), and hepatocellular carcinoma (HepG-2) human cancer cell lines using doxorubicin as a reference drug. The results demonstrated that, all hybrids displayed moderate to good anti-proliferative activity against the cell lines. The most active hybrids were 7a-d and 10c against CaCo-2 cancer cell line with IC50: 57.1, 52.78, 57.29, 51.95 and 56.74 µM, and selectivity index 1.38, 1.76, 2.6, 1.96 and 0.77; respectively. While, 7a,d were potent against A549 cancer cell line with IC50: 51.72, 54.8 µM and selectivity index 1.5, 0.67; respectively. Moreover, 7c showed the most potency against MDA-MB-231 cancer cell line with IC50: 50.96 µM and selectivity index 2.20. Interestingly, docking results revealed that binding energy of the current compounds showed marked affinity values ranging from -6.54 to -5.56 kcal with interactions with the reported key amino acid SER 79. Furthermore, the antimicrobial activity of the synthesized hybrids 7a-e, 10b,c, 13b and 13c were evaluated against Gram-positive and Gram-negative bacterial and fungal strains. The hybrids 10b, 13b, 10c, and 13c exhibited broad-spectrum antibacterial activity against E.coli, S. mutans, and S. aureus with MIC from 3.2 to 66 µM, this hybrids also displayed antifungal activity against C. albicans with MIC values ranging from 0.0011 to 29.5 µM. In-silico investigation of the pharmacokinetic properties indicated that tested hybrids had high GI absorption, low Blood Brain Barrier (BBB) permeability in addition to cell membrane penetrability.

Cytotoxic Potential of Novel Quinoline Derivative: 11-(1,4-Bisaminopropylpiperazinyl)5-methyl-5H-indolo[2,3-b]quinoline against Different Cancer Cell Lines via Activation and Deactivation of the Expression of Some Proteins

The current study evaluated the cytotoxic activity of 11-(1,4-bisaminopropylpiperazinyl)5-methyl-5H-indolo[2,3-b]quinoline (BAPPN), a novel derivative of 5-methyl-5H-indolo[2,3-b]quinoline, against hepatocellular carcinoma (HepG2), colon carcinoma (HCT-116), breast (MCF-7), and lung (A549) cancer cell lines and the possible molecular mechanism through which it exerts its cytotoxic activity. BAPPN was synthesized and characterized with FT-IR and NMR spectroscopy. The binding affinity scores of BAPPN for caspase-3 PDB: 7JL7 was -7.836, with an RMSD of 1.483° A. In silico screening of ADME properties indicated that BAPPN showed promising oral bioavailability records in addition to their high gastrointestinal absorption and blood-brain barrier penetrability. BAPPN induced cytotoxicity, with IC50 values of 3.3, 23, 3.1, and 9.96 μg/mL against cancer cells HepG2, HCT-116, MCF-7, and A549, respectively. In addition, it induced cell injury and morphological changes in ultracellular structure, including cellular delayed activity, vanishing of membrane blebbing, microvilli, cytoplasmic condensation, and shrunken nucleus with more condensed chromatin autophagosomes. Furthermore, BAPPN significantly increased the protein expression of caspase-3 and tumor suppressor protein (P53). However, it significantly reduced the secretion of vascular endothelial growth factor (VEGF) protein into the medium and decreased the protein expression of proliferation cellular nuclear antigen (PCNA) and Ki67 in HepG2, HCT-116, MCF-7, and A549 cells. This study indicates that BAPPN has cytotoxic action against liver, colon, breast, and lung cancer cell lines via the up-regulation of apoptotic proteins, caspase-3 and P53, and the downregulation of proliferative proteins, VEGF, PCNA, and Ki67.

In vivo and In silico evidence of the protective properties of carvacrol against experimentally-induced gastric ulcer: Implication of antioxidant, anti-inflammatory, and antiapoptotic mechanisms

Gastric ulcer is a serious disease that affects millions of individuals worldwide. Alcohol consumption is a major contributor to the disease pathogenesis and ethanol-induced ulcer in rats closely recapitulates the clinical pathology of ulcer. In this study, rats were pretreated with carvacrol (CAR,50 and 100 mg/kg, orally) 1 h before absolute ethanol administration to induce gastric ulcer. CAR prevented ethanol-induced increases in gastric volume and acidity while restored mucin content. The gastro-protective activity of CAR, particularly the higher dose (100 mg/kg), was further supported by histopathological examination, as manifested by reduced gastric lesions. Interestingly, oxidative stress is linked to early stages of ulcer development and progression. In this study, ethanol administration upregulated the levels of ROS-producing enzymes, NADPH oxidase homologs 1 and 4 (Nox1 and Nox4) and lipid peroxides while depleting the antioxidant defense mechanisms, including GSH, Glutathione Peroxidase (GPX) and catalase. Interestingly, these alterations were significantly ameliorated by CAR pretreatment. Additionally, CAR possesses anti-inflammatory and anti-apoptotic activities. Pretreatment with CAR blunted ethanol-induced increases in inflammatory cytokines (NF-κB and TNF-α) and rectified the apoptosis regulator (Bax/Bcl2 ratio) in gastric tissue. Moreover, the docking simulation of CAR illustrated good fitting and interactions with GPX, Nox1 and TNF-α through the formation of hydrogen and hydrophobic (pi-H) bonds with conservative amino acids, thus, further supporting the anti-inflammatory and antioxidant effects underlying the gastroprotective effects of CAR. In conclusion, this study elucidates, using in silico and in vivo models, that the gastroprotective activity of CAR is attributed, at least in part, to its mucin-secretagogue, antioxidative, anti-inflammatory, and anti-apoptotic mechanisms.

In Silico Screening and Anticancer-Apoptotic Evaluation of Newly Synthesized Thienopyrimidine/Sulfonamide Hybrids

This work describes the design and synthesis of new hybrids of thienopyrimidine and sulfonamides. The binding affinity of the prepared compounds to FGFR-1 enzyme and caspase-3 was investigated via molecular docking. The cytotoxic effect was estimated for the synthesized compounds against human breast cancer cell lines (MCF-7 and MDA-MB231) using Doxorubicin as a reference. All the tested compounds exhibited moderate to excellent anticancer efficacy against both tested cell lines, among which 3b and 4bi were the best. All the synthesized compounds exhibited distinguishing selectivity index values greater than Doxorubicin. The influence of the new hybrids under inquiry was further examined on both FGFR-1 and Caspase-3. The results revealed that compound 3b showed observed concordance between anti-proliferative activity and Caspase-3 activity. In respect to the compounds' effect on the apoptosis, compound 3b significantly increased the population of late apoptotic cells and necrotic cells. In silico pharmacokinetic investigation revealed that compound 3b showed the best intestinal absorption, BBB permeability, and, along with 4bi and 4bii, the best CNS penetrability.

Synthesis, Characterization, and Docking Study of Novel Thioureidophosphonate-Incorporated Silver Nanocomposites as Potent Antibacterial Agents

Newly synthesized mono- and bis-thioureidophosphonate (MTP and BTP) analogues in eco-friendly conditions were employed as reducing/capping cores for 100, 500, and 1000 mg L^-1 of silver nitrate. The physicochemical properties of silver nanocomposites (MTP(BTP)/Ag NCs) were fully elucidated using spectroscopic and microscopic tools. The antibacterial activity of the nanocomposites was screened against six multidrug-resistant pathogenic strains, comparable to ampicillin and ciprofloxacin commercial drugs. The antibacterial performance of BTP was more substantial than MTP, notably with the best minimum inhibitory concentration (MIC) of 0.0781 mg/mL towards Bacillus subtilis, Salmonella typhi, and Pseudomonas aeruginosa. Among all, BTP provided the clearest zone of inhibition (ZOI) of 35 ± 1.00 mm against Salmonella typhi. After the dispersion of silver nanoparticles (AgNPs), MTP/Ag NCs offered dose-dependently distinct advantages over the same nanoparticle with BTP; a more noteworthy decline by 4098 × MIC to 0.1525 × 10^-3 mg/mL was recorded for MTP/Ag-1000 against Pseudomonas aeruginosa over BTP/Ag-1000. Towards methicillin-resistant Staphylococcus aureus (MRSA), the as-prepared MTP(BTP)/Ag-1000 displayed superior bactericidal ability in 8 h. Because of the anionic surface of MTP(BTP)/Ag-1000, they could effectively resist MRSA (ATCC-43300) attachment, achieving higher antifouling rates of 42.2 and 34.4% at most optimum dose (5 mg/mL), respectively. The tunable surface work function between MTP and AgNPs promoted the antibiofilm activity of MTP/Ag-1000 by 1.7 fold over BTP/Ag-1000. Lastly, the molecular docking studies affirmed the eminent binding affinity of BTP over MTP-besides the improved binding energy of MTP/Ag NC by 37.8%-towards B. subtilis-2FQT protein. Overall, this study indicates the immense potential of TP/Ag NCs as promising nanoscale antibacterial candidates.

Molluscicidal and Larvicidal Potency of N-Heterocylic Analogs against Biomophalaria alexandrina Snails and Schistosoma mansoni Larval Stages

This work describes the synthesis of quinoline-based N--heterocyclic arenes and their biological evaluation as molluscicides against adult Biomophalaria alexandrina snails as well as larvicides against Schistosoma mansoni larvae (miracidia and cercariae). Molecular docking studies were demonstrated to investigate their affinity for cysteine protease protein as an interesting target for antiparasitics. Compound AEAN showed the best docking results followed by APAN in comparison to the co-crystallized ligand D1R reflected by their binding affinities and RMSD values. The egg production, hatchability of B. alexandrina snails and ultrastructural topography of S. mansoni cercariae using SEM were assessed. Biological evaluations (hatchability and egg-laying capacity) revealed that the quinoline hydrochloride salt CAAQ was the most effective compound against adult B. alexandrina snails, whereas the indolo-quinoline derivative APAN had the most efficiency against miracidia, and the acridinyl derivative AEAA was the most effective against cercariae and caused 100% mortality. CAAQ and AEAA were found to modulate the biological responses of B. alexandrina snails with/without S. mansoni infection and larval stages that will affect S. mansoni infection. AEAA caused deleterious morphological effects on cercariae. CAAQ caused inhibition in the number of eggs/snail/week and reduced reproductive rate to 43.8% in all the experimental groups. CAAQ and AEAA can be recommended as an effective molluscicide of plant origin for the control program of schistosomiasis.

Impact of Synthesized Indoloquinoline Analog to Isolates from Cryptolepis sanguinolenta on Tumor Growth Inhibition and Hepatotoxicity in Ehrlich Solid Tumor-Bearing Female Mice

The study evaluated the antitumor efficacy of APAN, “synthesized indoloquinoline analog derived from the parent neocryptolepine isolated from the roots of Cryptolepis sanguinolenta”, versus the chemotherapeutic drug etoposide (ETO) in Ehrlich solid tumor (EST)-bearing female mice as well as its protective effect against etoposide-triggered hepatic disorders. APAN showed an ameliorative activity against Ehrlich solid tumor and hepatic toxicity, and the greatest improvement was found in the combined treatment of APAN with ETO. The results indicated that EST altered the levels of tumor markers (AFP, CEA, and anti-dsDNA) and liver biomarker function (ALT, AST, ALP, ALB, and T. protein). Furthermore, EST elevated CD68 and anti-survivin proteins immuno-expressions in the solid tumor and liver tissue. Molecular docking studies were demonstrated to investigate their affinity for both TNF-α and topoisomerase II as target proteins, as etoposide is based on the inhibition of topoisomerase II, and TNF-α is quite highly expressed in the solid tumor and liver tissues of EST-bearing animals, which prompted the authors’ interest to explore APAN affinity to its binding site. Treatment of mice bearing EST with APAN and ETO nearly regularized serum levels of the altered parameters and ameliorated the impact of EST on the tissue structure of the liver better than that by treatment with each of them separately.

Design, Synthesis, and Antiproliferative Activity of Novel Neocryptolepine-Rhodanine Hybrids

A series of novel neocryptolepine-rhodanine hybrids (9a,b, 11a-d, 14, and 16a,b) have been synthesized by combining neocryptolepine core 5 modified at the C-11 position with rhodanine condensed with the appropriate aryl/hetero aryl aldehydes. Based on these findings, the structures of the hybrids were confirmed by spectral analyses. By employing the MTT assay, all hybrids were tested for their in vitro antiproliferative activity against two cancer cell lines, including MDA-MB-231 (human breast) and HepG-2 (hepatocellular carcinoma). Interestingly, the IC50 values of all hybrids except 9b and 11c showed activity comparable to the standard anticancer drug, 5-fluorouracil, against HepG-2 cancer cells. Furthermore, the cytotoxicity of all the synthesized hybrids was investigated on a normal skin human cell line (BJ-1), and the results showed that these compounds had no significant cytotoxicity toward these healthy cells at the highest concentration used in this study. This study also indicated that the active hybrids exert their cytotoxic activity via the induction of apoptosis. A molecular docking study was used to shed light on the molecular mechanism of their anticancer activity. The docking results revealed that the hybrids exert their mode of action through DNA intercalation. Furthermore, in silico assessment for pharmacokinetic properties was performed on the most potent compounds, which revealed candidates with good bioavailability, high tolerability with cell membranes, and positive drug-likeness values.

Synthesis, Biocidal and Antibiofilm Activities of New Isatin-Quinoline Conjugates against Multidrug-Resistant Bacterial Pathogens along with Their In Silico Screening

Isatin-quinoline conjugates 10a-f and 11a-f were assembled by the reaction of N-(bromobutyl) isatin derivatives 3a, b with aminoquinolines 6a-c and their corresponding hydrazinyl 9a-c in good yields. The structures of the resulting conjugates were established by spectroscopic tools and showed data consistent with the proposed structures. In vitro antibacterial activity against different bacterial strains was evaluated. All tested conjugates showed significant biocidal activity with lower MIC than the first line drugs chloramphenicol and ampicillin. Conjugates 10a, 10b and 10f displayed the most potent activity against all clinical isolates. The antibiofilm activity for all tested conjugates was screened against the reference drug vancomycin using the MRSA strain. The results revealed that all conjugates had an inhibitory activity against biofilm formation and conjugate. Conjugate 11a showed 83.60% inhibition at 10 mg/mL. In addition, TEM studies were used to prove the mechanism of antibacterial action of conjugates 10a and 11a against (MRSA). Modeling procedures were performed on 10a-f and 11a-f and interestingly the results were nearly consistent with the biological activities. In addition, in silico pharmacokinetic evaluation was performed and revealed that the synthesized compounds 10a-f and 11a-f were considered drug-like molecules with promising bioavailability and high GI absorption. The results confirmed that the title compounds caused the disruption of bacterial cell membranes and could be used as potential leads for the further development and optimization of antibacterial agents.

Design and Synthesis of New Thiophene/Thieno[2,3-d]pyrimidines along with Their Cytotoxic Biological Evaluation as Tyrosine Kinase Inhibitors in Addition to Their Apoptotic and Autophagic Induction

This work describes the synthesis and anticancer activity against kinase enzymes of newly designed thiophene and thieno[2,3-d]pyrimidine derivatives, along with their potential to activate autophagic and apoptotic cell death in cancer cells. The designed compounds were scanned for their affinity for kinases. The results were promising with affinity ranges from 46.7% to 13.3%. Molecular docking studies were performed, and the compounds were then screened for their antiproliferative effects. Interestingly, compounds 8 and 5 resulted in higher cytotoxic effects than the reference standard against MCF-7 and HepG-2. The compounds were evaluated for their induction of apoptosis and/or necrosis on HT-29 and HepG-2. Three compounds induced significant early apoptosis compared to untreated control HT-29 cells, and four derivatives were more significant compared to untreated HepG-2 cells. We further investigated the effect of four compounds on the autophagy process within HT-29, HepG-2, and MCF-7 cells with flow cytometry. Similar to the apoptosis results, compound 5 showed the highest autophagic induction among all compounds. The potential inhibitory activity of the synthesized compounds on kinases was assessed. Screened compounds showed inhibition activity ranging from 41.4% to 83.5%. Compounds recorded significant inhibition were further investigated for their specific FLT3 kinase inhibitory activity. Noticeably, Compound 5 exhibited the highest inhibitory activity against FLT3.

Elucidation of Phytochemical Content of Cupressus macrocarpa Leaves: In Vitro and In Vivo Antibacterial Effect against Methicillin-Resistant Staphylococcus aureus Clinical Isolates

Methicillin-resistant Staphylococcus aureus (MRSA) is an important human pathogen that causes various infections. The increasing resistance of MRSA to different antibiotics is widely spreading; therefore, plant extracts may be novel therapeutic alternatives. The phytochemical profiling of Cupressus macrocarpa Hartw. ex Gordon leaves in vitro, and in vivo, antimicrobial potential of its extracts against MRSA clinical isolates were explored. A phytochemical tentative identification of 49 compounds was performed in the leaves using LC-ESI-MS/MS; in addition, isolation, and structure elucidation of hesperidin and eriocitrin were achieved for the first time. The diethyl ether extract (DEEL) exhibited the best antibacterial effect with MIC values ranging from 2 to 8 µg/mL, which significantly reduced the growth and efflux activity in 48.78% and 29.26% of isolates, respectively. qRT-PCR showed a significant down expression of norA and norB genes, which significantly affected the bacterial cell morphology and had a non-significant effect on membrane depolarization (using flow cytometry). In a rat model, four groups were wounded and treated with normal saline or DEEL, or infected with MRSA, or infected and treated with DEEL. The regeneration of the epidermis, maturation of granulation tissue, and reduction of inflammatory cell infiltration were observed after treatment with DEEL. Thus, C. macrocarpa leaves may be a promising source for new antimicrobials against MRSA.

In Vitro and In Vivo Antitumor Activity of Indolo[2,3-b] Quinolines, Natural Product Analogs from Neocryptolepine Alkaloid

Neocryptolepine (5-methyl-5H-indolo[2,3-b] quinoline) analogs were synthesized and evaluated in vitro and in vivo for their effect versus Ehrlich ascites carcinoma (EAC). The analogs showed stronger cytotoxic activity against EAC cells than the reference drug. The in vivo evaluation of the target compounds against EAC-induced solid tumor in the female albino Swiss mice revealed a remarkable decrease in the tumor volume (TV) and hepatic lipid peroxidation. A noticeable increase of both superoxide dismutase (SOD) and catalase (CAT) levels was reported (p < 0.001), which set-forth proof of their antioxidant effect. In addition, the in vitro antioxidant activity of the neocryptolepine analogs was screened out using the DPPH method and showed promising activities activity. The histopathological investigations affirmed that the tested analogs have a remarkable curative effect on solid tumors with minimal side-effect on the liver. The study also includes illustrated mechanism of the antitumor activity at the cell level by flow cytometry. The cell cycle analysis showed that the neocryptolepine analogs extensively increase the aggregation of tumor cells in three phases of the cell cycle (G0/G1, S and G2/M) with the emergence of a hypo-diploid DNA content peak (sub-G1) in the cell cycle experiments, which is a clear-cut for the apoptotic cell population. Furthermore, the immunological study manifested a significant elevation in splenic lymphocyte count (p < 0.001) with the elevation of the responsiveness of lymphocytes to phytohemagglutinin (PHA). These results indicate that these naturally-based neocryptolepine alkaloids exhibit marked antitumor activity in vivo and represent an important lead in the development of natural-based anticancer drugs.