Novel mandelic acid derivatives containing piperazinyls as potential candidate fungicides against Monilinia fructicola: Design, synthesis and mechanism study.

Brown rot of stone fruit, a disease caused by the ascomycete fungus Monilinia fructicola, has caused significant losses to the agricultural industry. In order to explore and discover potential fungicides against M. fructicola, thirty-one novel mandelic acid derivatives containing piperazine moieties were designed and synthesized based on the amide skeleton. Among them, target compound Z31 exhibited obvious in vitro antifungal activity with the EC50 value of 11.8 mg/L, and significant effects for the postharvest pears (79.4 % protective activity and 70.5 % curative activity) at a concentration of 200 mg/L. Antifungal activity for the target compounds was found to be significantly improved by the large steric hindrance of the R1 groups and the electronegative of the piperazines in the molecular structure, according to a three-dimensional quantitative structure-activity relationship (3D-QSAR) analysis. Further mechanism studies have demonstrated that the compound Z31 can disrupt cell membrane integrity, resulting in increased membrane permeability, release of intracellular electrolytes, and affect the normal growth of hyphae. Additional, morphological study also indicated that Z31 may disrupt the integrity of the membrane by inducing generate excess endogenous reactive oxygen species (ROS) and resulting in the peroxidation of cellular lipids, which was further verified by the detection of malondialdehyde (MDA) content. These studies have provided the basis for the creation of novel fungicides to prevent brown rot in stone fruits.

Profiling of secondary metabolite and evaluation of anti-diabetic potency of Crotalaria quinquefolia (L): In-vitro, in-vivo, and in-silico approaches.

Traditional medicinal plants have played a promising role in the human health system. In folklore medicine, Crotalaria quinquefolia L. is used to treat fever, pain, eczema, impetigo, lung infections, scabies. The present investigation was executed to identify secondary metabolites responsible for anti-diabetic potential of C. quinquefolia L. leaf extract along with their possible mechanistic pathways. The anti-hyperglycemic activity was assessed by in vitro α-amylase and α-glucosidase inhibitory assays and an in vivo oral glucose tolerance test and diabetogenic effect of streptozotocin in mice, followed by an integrative computational analysis. A total of 23 compounds were identified through GCMS and HPLC. The extract showed potent in-vitro α-amylase and α-glucosidase suppressive activity with IC50 values of 12.8 ± 0.1 µg/mL and 36.3 ± 0.07 µg/mL, respectively. In an in vivo oral glucose tolerance test, the extract (400 mg/kg body weight) prompted blood glucose levels to plummet by 18.9 % after 30 min, compared to the normal control and streptozotocin induced diabetes test, maximum glucose reduction was observed 11.67 % by dose of 200 mg/kg compared to the control; glibenclamide and extract (400 mg/kg) reduced blood glucose levels by 1.3 % and 16.7 %, respectively, compared to diabetic control at the end of the trial. Additionally, among the identified compounds, myricetin, quercetin, rutin, and kaempferol revealed good binding affinity as well as stability with the studied anti-diabetic proteins in docking and molecular dynamics simulation studies. Furthermore, QSAR analysis and network pharmacology studies of the identified compounds divulged enhanced insulin secretion stimulation, insulin receptor kinase activity, PPARγ expression; enzyme inhibition (α-glucosidase, α-amylase) and protection of the pancreas -mediated antidiabetic effects. Besides, they proved strong inhibitory potential against the studied antidiabetic proteins in other computational analysis. Based on the present findings, it can be affirmed that C. quinquefolia extract possesses anti-diabetic activity.

Novel 2-aryl-4-aryloxyquinoline-based fungistatics for Mucor circinelloides. Biological evaluation of activity, QSAR and docking study.

Zygomycetes are ubiquitous saprophytes in natural environments which transform organic matter. Some zygomycetes of gender Mucor have attracted interest in health sector. Due to its ability as opportunistic microorganisms infecting immuno-compromised people and to the few available pharmacological treatments, the mucormycosis is receiving worldwide attention. Concerning to the pharmacological treatments, some triazole-based compounds such as fluconazole are extensively used. Nevertheless, we focused in the quinolines since they are broadly used models for the design and development of new synthetic antifungal agents. In this study, the fungistatic activity on M. circinelloides of various 2-aryl-4-aryloxyquinoline-based compounds was discovered, and in some cases, it resulted better than reference compound fluconazole. These quinoline derivatives were synthesized via the Csp2-O bond formation using diaryliodonium(III) salts chemistry. A QSAR study was carried out to quantitatively correlate the chemical structure of the tested compounds with their biological activity. Also, a docking study to identify a plausible action target of our more active quinolines was carried out. The results highlighted an increased activity with the fluorine- and nitro-containing derivatives. In light of the few mucormycosis pharmacological treatments, herein we present some non-described molecules with excellent in vitro activities and potential use in the mucormycosis treatment.

Synthesis, molecular modelling and QSAR study of new N-phenylacetamide-2-oxoindole benzensulfonamide conjugates as carbonic anhydrase inhibitors with antiproliferative activity.

In continuation of our previous studies to optimise potent carbonic anhydrase inhibitors, two new series of isatin N-phenylacetamide based sulphonamides were synthesised and screened for their human (h) carbonic anhydrase (EC 4.2.1.1) inhibitory activities against four isoforms hCA I, hCA II, hCA IX and hCA XII. The indole-2,3-dione derivative 2h showed the most effective inhibition profile against hCAI and hCA II (KI = 45.10, 5.87 nM) compared to acetazolamide (AAZ) as standard inhibitor. Moreover, 2h showed appreciable inhibition activity against the tumour-associated hCA XII, similar to AAZ showing KI of 7.91 and 5.70 nM, respectively. The analogs 3c and 3d showed good cytotoxicity effects, and 3c revealed promising selectivity towards lung cell line A549. Molecular docking was carried out for 2h and 3c to predict their binding conformations and affinities towards the hCA I, II, IX and XII isoforms.

QSAR Modeling, Molecular Docking and Cytotoxic Evaluation for Novel Oxidovanadium(IV) Complexes as Colon Anticancer Agents.

Four new drug-based oxidovanadium (IV) complexes were synthesized and characterized by various spectral techniques, including molar conductance, magnetic measurements, and thermogravimetric analysis. Moreover, optimal structures geometry for all syntheses was obtained by the Gaussian09 program via the DFT/B3LYP method and showed that all of the metal complexes adopted a square-pyramidal structure. The essential parameters, electrophilicity (ω) value and expression for the maximum charge that an electrophile molecule may accept (ΔNmax) showed the practical biological potency of [VO(CTZ)2] 2H2O. The complexes were also evaluated for their propensity to bind to DNA through UV-vis absorption titration. The result revealed a high binding ability of the [VO(CTZ)2] 2H2O complex with Kb = 1.40 × 106 M-1. Furthermore, molecular docking was carried out to study the behavior of the VO (II) complexes towards colon cancer cell (3IG7) protein. A quantitative structure-activity relationship (QSAR) study was also implemented for the newly synthesized compounds. The results of validation indicate that the generated QSAR model possessed a high predictive power (R2 = 0.97). Within the investigated series, the [VO(CTZ)2] 2H2O complex showed the greatest potential the most selective compound comparing to the stander chemotherapy drug.

Design, synthesis, antibacterial evaluation, and computational studies of hybrid oxothiazolidin-1,2,4-triazole scaffolds.

Bacterial infections are a serious threat to human health due to the development of resistance against the presently used antibiotics. The problem of growing and widespread antibiotic resistance is only getting worse with the shortage of new classes of antibiotics, creating a substantial unmet medical need in the treatment of serious bacterial infections. Therefore, in the present work, we report 18 novel hybrid thiazolidine-1,2,4-triazole derivatives as DNA gyrase inhibitors. The derivatives were synthesized by multistep organic synthesis and characterized by spectroscopic methods (1 H and 13 C nuclear magnetic resonance and mass spectroscopy). The derivatives were tested for DNA gyrase inhibition, and the result emphasized that the synthesized derivatives have a tendency to inhibit the function of DNA gyrase. Furthermore, the compounds were also tested for antibacterial activity against three Gram-positive (Bacillus subtilis [NCIM 2063], Bacillus cereus [NCIM 2156], Staphylococcus aureus [NCIM 2079]) and two Gram-negative (Escherichia coli [NCIM 2065], Proteus vulgaris [NCIM 2027]) bacteria. The derivatives showed a significant-to-moderate antibacterial activity with noticeable antibiofilm efficacy. Quantitative structure-activity relationship (QSAR), ADME (absorption, distribution, metabolism, elimination) calculation, molecular docking, radial distribution function, and 2D fingerprinting were also performed to elucidate fundamental structural fragments essential for their bioactivity. These studies suggest that the derivatives 10b and 10n have lead antibacterial properties with significant DNA gyrase inhibitory efficacy, and they can serve as a starting scaffold for the further development of new broad-spectrum antibacterial agents.

Novel Pyrimidine Derivatives as Potential Anticancer Agents: Synthesis, Biological Evaluation and Molecular Docking Study.

In the present paper, new pyrimidine derivatives were designed, synthesized and analyzed in terms of their anticancer properties. The tested compounds were evaluated in vitro for their antitumor activity. The cytotoxic effect on normal human dermal fibroblasts (NHDF) was also determined. According to the results, all the tested compounds exhibited inhibitory activity on the proliferation of all lines of cancer cells (colon adenocarcinoma (LoVo), resistant colon adenocarcinoma (LoVo/DX), breast cancer (MCF-7), lung cancer (A549), cervical cancer (HeLa), human leukemic lymphoblasts (CCRF-CEM) and human monocytic (THP-1)). In particular, their feature stronger influence on the activity of P-glycoprotein of cell cultures resistant to doxorubicin than doxorubicin. Tested compounds have more lipophilic character than doxorubicin, which determines their affinity for the molecular target and passive transport through biological membranes. Moreover, the inhibitory potential against topoisomerase II and DNA intercalating properties of synthesized compounds were analyzed via molecular docking.

Design, synthesis and QSAR study of 2'-hydroxy-4'-alkoxy chalcone derivatives that exert cytotoxic activity by the mitochondrial apoptotic pathway.

Eleven 4'-alkoxy chalcones were synthesized and biologically evaluated for their antiproliferative activity against four human tumor cell lines (PC-3, MCF-7, HF-6, and CaSki). Compounds 3a-3d and 3f were selective against PC-3, with IC50 values ranging from 8.08 to 13.75 µM. In addition, chalcones 3a-3c did not affect the normal fibroblasts BJ cells. The most active and selective compounds were further evaluated for their effect on the progression of cell cycle in PC-3 cells, and chalcones 3a and 3c induced a G2/M phase arrest. Furthermore, it was found that these three chalcones induced the mitochondrial apoptotic pathway by regulating Bax and Bcl-2 transcripts and by increasing caspase 3/7 activation. Otherwise, the QSAR model indicates that the double bond of the α,ß-unsaturated carbonyl, as well as the planar structure geometry, are important to the biological activity of the synthetized chalcones. Based on these studies, it was concluded that withdrawing substituents in ring A, decrease the antiproliferative activity. This is related to the possible mechanism of action of these compounds, where a Michael addition needs to take place in order to be a potent anticancer agent.

Evaluations of imidazolium ionic liquids as novel skin permeation enhancers for drug transdermal delivery.

In this work, imidazolium ionic liquids (imidazolium ILs) were employed as the novel chemical permeation enhancers (CPEs) and their performances and mechanisms of action were deeply investigated. Testosterone was used as a model drug to investigate the transdermal delivery enhancement of twenty imdidazolium ILs. The results suggested that the promotion activity connected to the structure and composition of the ILs. The quantitative structure-activity relationship (QSAR) model revealed a good linearity between the electronic properties of ILs and their enhancements. Furthermore, the transepidermal water loss (TEWL) and scanning laser confocal microscope (CLSM) examinations showed the strong improvement of ILs on skin barrier permeability, which were well correlated with the drug penetration profiles. The total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and atomic force microscope (AFM) evaluations of skins indicated that the ILs can disrupt the regular and compact arrangements of the corneocytes, change the surface properties of stratum corneum, and make the skin structure more permeable. Our work demonstrated the significant skin permeation promotion profiles of the imidazolium ILs, which are of great potential in transdermal drug delivery systems.

Synthesis and computational studies of novel fused pyrimidinones as a promising scaffold with analgesic, anti-inflammatory and COX inhibitory potential.

Addressing the global need for the development of safe and potent NSAIDs, new series of oxadiazolo and thiadiazolo fused pyrmidinones were synthesized and initially tested for their analgesic activity. All tested compounds showed promising analgesic activity compared with the reference standard indomethacin. Moreover, anti-inflammatory activity evaluation, ulcerogenic liability, and in vitro COX-1, COX-2 enzyme inhibition assays were also performed for the most active derivatives. The methoxyphenyl piperazinyl derivative 3d showed analgesic activity surpassing indomethacin with protection of 100%, and 83%; respectively. Also 3d showed good anti-inflammatory activity with relatively lower ulcer index compared with other tested compounds, and potent COX-1 and COX-2 inhibitory activity with IC50 = 0.140, 0.007 µm, respectively, and with a selectivity index of 20.00 which was better than the reference standards and the other tested congeners. Additionally, compounds 3b, 3g and 3h revealed moderate selectivity (SI = 3.53, 3.70 and 5.87, respectively). Moreover, in silico physicochemical parameters revealed that the new fused pyrimidinones demonstrated promising pharmacokinetic properties. Furthermore, computational studies in form of 2D-quantitative structure-activity relationship (2D-QSAR) and 3D-pharmacophore confirmed the potential analgesic properties of the new target compounds.

Turpentine Derived Secondary Amines for Sustainable Crop Protection: Synthesis, Activity Evaluation and QSAR Study.

In this study, we will report on the synthesis and application of efficient botanical agrochemicals from turpentine for sustainable crop protection. Two series of turpentine derived secondary amines were synthesized and identified by FT-IR, 1H NMR, 13C NMR, and HRMS. The herbicidal activities against Echinochloa crus-galli were evaluated. The potential toxicity of the synthesized compounds was tested by MTT cytotoxicity analysis. The effect of structure of the synthesized secondary amines and corresponding Schiff base compounds on their activities was investigated by quantitative structure-activity relationship (QSAR) study. All target products were found to be low toxicity, with similar or higher herbicidal activities than commercial herbicides diuron and Glyphosate. Results of QSAR study showed that a best four-descriptor QSAR model with R2 of 0.880 and Rloo2 of 0.818 was obtained. The four descriptors most relevant to the herbicidal activities are the min valency of a N atom, the max total interaction for a C-H bond, the relative number of aromatic bonds, and the min partial charge (Qmin).

Novel 1,3,4-Triaryl Pyrazoles: Synthesis, QSAR Studies and Cytotoxicity against Breast Cancer.

BACKGROUND: The existence of drug-resistance and lack of selectivity encourages scientists to search for novel and more selective cytotoxic agents. OBJECTIVES: In this work, novel 1,3,4-triarylpyrazole derivatives were synthesized to study their cytotoxicity on MCF7 (human breast Cell Line). In addition, QSAR studies were performed to show the relation between the cytotoxic activity and the structural features of our new synthesized pyrazole derivatives. METHODS: Pyrazole-4-carbaldehyde derivative 3 was utilized as a starting material for the preparation of the new pyarazole derivatives. These target compounds were screened for their cytotoxic activity against MCF-7 followed by study cell cycle of the most active compounds. Finally, pharmacophore modeling and QSAR Studies was carried out. RESULTS: Among these compounds; 5d and 8b showed the highest anti-proliferative activity (IC50 = 4.9 and 2.11 µM, respectively). Flow cytometric analysis showed that, compounds 5d and 8b arrested the cell cycle in addition to induction of apoptosis in MCF7 cells. Moreover, their stimulation effect on caspases 3/7 was examined to explore their mechanism of induction of apoptosis and the results showed that their proapoptotic activity could be due to the activation of caspases 3/7. CONCLUSION: Pyrazole derivatives 5d and 8b displayed potent bioactivities, indicating that these compounds could be considered as a new lead for more investigation in the future.

Development of leads targeting ER-α in breast cancer: An in silico exploration from natural domain.

The steroid, estrogen has been recognized as being important for stimulating the growth of breast cancers primarily mediated via the steroidal estrogen receptor-α (ER-α). Inhibition of estrogen activity by small molecules with increased target specificity has proven to be an effective treatment for breast cancer. After the success stories of SERMs and fulvestrant, there is a need for the development of new small molecule modulating ER-α is due to developing resistance and side effects to current breast cancer therapy. In this pursuit, we virtually screened 227 chemically diverse bioactive natural products to get the best hits having an ER-α binding affinity. The docking scores and protein-ligand interactions of the obtained hits were emulated with the clinically used selective estrogen modulators and ER-antagonists. The results revealed 18 potential hits, which were putatively classified as hits belonging to ER agonists, modulators, and antagonists. Furthermore, as most of the hits were found to comprise the chromene nucleus, the 2D and 3D QSAR studies were performed using a set of natural products and synthesized compounds containing this scaffold, to understand the structural requirements for improving activity against breast cancer. Additionally, a pharmacophore model was generated to investigate the pharmacophoric features of the explored scaffolds for an optimal anticancer activity. The results signify that these compounds with structural modification could serve as potential leads in the drug discovery process for the treatment of breast cancer.

Designing of Selective γ-Secretase Inhibitory Benzenesulfonamides through Comparative In Vitro and In Silico Analysis.

BACKGROUND: In Alzheimer's disease (AD), the gene mutations have been identified in the amyloid precursor protein (APP), the presenilin-1 (PS1) and -2 (PS2) genes. APP is a transmembrane protein which gets cleaved by α- and ß- secretase enzymes and releases Aß peptides which forms senile plaques in brain tissue. It contributes for local inflammatory response, subsequent oxidative stress, biochemical changes and neuronal death. Targeting the development of Aß aggregates in the senile plaques is an important strategy in the treatment of AD. To facilitate the normal processing of APP, some of the reported approaches are stimulation of α- secretase activity or the modulation/inhibition of the ß- and γ-secretase complex. METHODS: The mechanism of γ-secretase inhibition is targeted based on the QSAR and molecular docking methods. The series based on 3-chloro-2-hydroxymethylbenzenesulfonamide was selected for in silico ligand-based modeling. Significant correlations, between their γ-Secretase inhibitory profile and 2D-descriptors, were obtained through multiple linear regression (MLR) computational procedure. RESULTS: During QSAR nalysis, calculated molar refractivity (CMR) and surface tension (ST) were found to be contributing parameters along with halogen substituent at a particular position. Applicability analysis revealed that the suggested models have acceptable predictability (rpred2 = 0.827). CONCLUSION: The inferences drawn from MLR were utilized to prepare a data set of fourteen substituted benzenesulfonamides (N1-N14). The in silico studies provides strong impetus towards systematic application of such methods during lead identification and optimization.

A QSAR study on some series of anti-hepatitis B virus (HBV) agents.

A quantitative structure-activity relationship (QSAR) study has been made on some series of anti-hepatitis B virus (HBV) agents, namely, a series of novel bis(L-amino acid) ester prodrugs of 9-[2--(phosphonomethoxy)ethyl]adenine, a similar series of compounds comprising of 2- amino-6-arylthio-9-[2-(phosphonoethoxy)ethyl] purine bis(2,2,2- trifluoroethyl) esters, and a series of 1-isopropylsulfonyl-2-amine benzimidazoles. In each case significant correlations are found between the anti-HBV potencies and some physicochemical and steric properties of the compounds, indicating that for the first two series the activity is controlled by the hydrophobic and the bulk properties of the molecules and, for the third series, the steric and hydrogen bonding properties of compounds are crucial for their anti-HBV potency.