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Κυριακή 17 Νοεμβρίου 2019

Design, synthesis, molecular docking, antimicrobial, and antioxidant activities of new phenylsulfamoyl carboxylic acids of pharmacological interest

Abstracts

The research explores the facile synthesis of some new phenylsulfamoyl carboxylic acids, their molecular docking, antimicrobial, and antioxidant activities. The procedure involved the mild reaction of amino acids with benzenesulfonyl chloride in a medium of aqueous base. The compounds were characterized using FTIR, 1H-NMR, 13C-NMR, and an elemental analysis. They were tested for their antimicrobial activities against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Salmonella typhi, Candida albicans, and Aspergillus niger microorganisms. The antioxidant activity of the compounds were measured in vitro by the inhibition of generated stable 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical. The molecular docking was carried out properly and five different disease conditions were studied, namely: trypanosomiasis, malaria, bacterial, fungal infections, and oxidative stress. From the results, compounds 4c4d4e, and 4g possess more excellent in vitro antibacterial and antifungal activities than the standard drug Ofloxacin used. Compound 4e displayed the most excellent antioxidant activity. Compound 4g showed significant 2D interaction with amino acid residue of urate oxidase from Aspergillus flavus complexed with uracil. Interestingly, compounds 4a4c4d4e, and 4g exhibited excellent antibacterial, antifungal, antioxidant, antitrypanosome, and antimalaria activities comparable to the corresponding standard drugs such as Penicillin, Ketoconazole; α-Tocopherol, Melarsoprol, and Chloroquine respectively. All the compounds were confirmed drug-like according to “Lipinski’s rule of five”. The compounds were found to be promising antibacterial, antifungal, antioxidant, and antitrypanosome agents.

Synthesis and cytotoxic activity of 3-amino substituted fusidane triterpenoids

Abstract

New 3-amino substituted derivatives, containing linear, aromatic, and heterocyclic fragments, as well as conjugates with biogenic amines—spermine and spermidine, were synthesized from 3,11-dioxo analogs of fusidic acid and its methyl ester. Antitumor activity of the compounds was studied in vitro towards the 60 cell lines of nine different types of human tumors of the NCI collection. Introduction of pyrrolidine, n-butylamine, benzylamine, and ethylenediamine substituents into the molecules were found to provide a pronounced selective effect on five cell lines of leukemia: HL-60, K-562, MOLT-4, RPMI-8226, and SR, inhibiting their growth from 70% to complete death of cancer cells. Methylfusidate derivative with a spermine fragment was shown to exhibit the widest spectrum of antiproliferative action among the obtained compounds, inhibiting the growth of leukemia, NSC lung cancer, colon cancer, and melanoma cell lines of 68–92%.

Structure-antioxidant activity relationships, QSAR, DFT calculation, and mechanisms of flavones and flavonols

Abstract

DFT calculations were performed on nine flavones and flavonols to explain their high antioxidant activity and variations in their activity. Conformational analysis showed that only flavonols with 3-OH directed toward the B-ring are nonplanar; however, flavones and resulted radicals are planar. Hydroxyl group eligible for dissociation is the one with ortho OH directed toward it; otherwise, one of B-ring (in 2′ or 4′-position) hydroxyl group. There are two main factors responsible for stabilizing the resulted radicals and lowering the bond dissociation energy and hence there were found well correlated with the experimental activity. First, driving force resulted from the conversion of nonplanar flavonols to planar radicals accompanied by resonance toward the carbonyl group and H-bond formation with 3-OH and second, radical stabilization by H-bond with ortho hydroxyl group with resonance toward carbonyl or pyrone oxygen. All resonance and H-bonds were confirmed by spin density, bond length, and molecular orbital calculations.

Synthesis and anticancer effects of conjugates of doxorubicin and unsaturated fatty acids (LNA and DHA)

Abstract

Doxorubicin (DOX) is a leading cytostatic drug with many adverse effects in use. We are still looking for methods that will allow us to preserve the therapeutic effect against the tumor cells and reduce the toxicity to the normal cells. In our work, we obtained amide derivatives of DOX by reaction of the amino group with α-linolenic (LNA) and docosahexaenoic (DHA) acids (23), as well as double-substituted derivatives via amide and ester linkages (45). The structures of the compounds were confirmed by Proton Nuclear Magnetic Resonance (1H NMR), Carbon-13 Nuclear Magnetic Resonance (13C NMR), and High Resolution Mass Spectrometry (HRMS) analyses. For all compounds 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide (MTT) assay was used to determine the cytotoxic effect on human cancer cell lines (SW480, SW620, and PC3) and Chinese hamster lung fibroblasts (V79) that were used as a control. The cytotoxic activity was established by calculation of the inhibitory concentration IC50. In addition, a cytotoxic capacity against tumor cells for tested compounds was expressed as a selectivity factor (selectivity index, SI). Lactate dehydrogenase (LDH) assay was performed for all compounds to assess the level of cell damage. To explain the basic mechanism of cell death induction the Annexin V-FITC/IP flow cytometry analysis was investigated. We found that all studied conjugates exhibit lower cytotoxicity but higher selectivity than DOX. Among the all derivatives, the conjugates formed by the amide and ester linkages (45) were found to be more promising compared with conjugates (23) formed only by the amide linkage. They show high cytotoxicity toward the tumor cell lines and moderate cytotoxicity towards the normal cell line.

New antimalarial lanostane triterpenes from a new isolate of Egyptian Ganoderma species

Abstract

Two new lanostane triterpenes named ganoderic acid AW1 (1) and ganoderic acid AW2 (2) were isolated from the fungal fruiting bodies of the cultivated new isolate of the Egyptian Ganoderma sp in addition to the known compounds ganomycine A (3), pinellic acid (4), and ergosterol peroxide (5). Their structures were elucidated by detailed analysis of their 1D and 2D-NMR data, as well as high-resolution mass spectroscopy. Ganoderic acid AW1 (1) showed good antimalarial activity against the chloroquine sensitive strain of Plasmodium falciparum with an IC50 value of 257.8 nM with no cytotoxicity up to the concentration of 9 μM.

Identification of prodigious and under-privileged structural features for RG7834 analogs as Hepatitis B virus expression inhibitor

Abstract

In the present work, QSAR (quantitative structure−activity relationship) analysis has been executed for RG7834 analogs. RG7834 is a first-in-class selective and orally available dihydroquinolizinone (DHQ)-based small molecule Hepatitis B virus expression inhibitor. OECD’s guidelines have been followed for developing multiple QSAR models for Hepatitis B virus expression inhibitory activity of 73 RG7834 analogs. The present multiple QSAR models are not only easily interpretable but possess high external predictive ability, as well. These are effective in the recognition of many privileged and underprivileged molecular descriptors, which could be very valuable for the use of these models by the experts and nonexperts of QSAR in future optimizations. The models satisfy threshold values for many fitting, internal and external validation parameters, such as R2 = 0.83, Q2 = 0.80, CCCext = 0.88, etc., thereby demonstrating good external predictive ability of the models. The multiple QSAR and pharmacophoric models successfully identified a good number of important positively and negatively related structural features of RG7834 analogs that govern their Hepatitis B virus expression inhibitory activity. The results could be very beneficial to synthetic/medicinal chemists for future alterations of RG7834 analogs as better drug candidates.

Acetone effects on Buddleja scordioides polyphenol extraction process and assessment of their cellular antioxidant capacity and anti-inflammatory activity

Abstract

The use of water, acetone, and hydroacetonic solutions as an extraction solvent for polyphenol compounds from Buddleja scordioides has been investigated. The phenolic profiles determined by liquid chromatography—electrospray ionization—mass spectrometry/mass spectrometry (LC–ESI–MS/MS) were compared with those obtained with the traditional aqueous infusion used for the treatment of gastrointestinal disorders. It was evaluated the effects of polyphenol extract at physiologically relevant conditions against H2O2-induced oxidative stress via attenuation of reactive oxygen species (ROS) levels and lipopolysaccharide (LPS)-induced inflammation in human HT-29 cells. The use of hydroacetonic solutions allows obtaining phytochemical extracts enriched with constituents that have antioxidant and anti-inflammatory activity in intestinal cells. This suggests that polyphenols of low and middle polarity from Buddleja scordioides may be better extracted with hydroacetonic solutions, and showing high nutraceutical potential to reduce oxidative stress associated with the onset and progress of inflammatory diseases.

Synthesis of dehydro-α-lapachones, α- and β-lapachones, and screening against cancer cell lines

Abstract

14 new naphthoquinones were prepared and tested against human cancer cell lines PC-3 (prostate), HCT-116 (colon carcinoma), SNB-19 (glioblastoma), HL-60 (leukemia) and MCF-7 (breast), and a nontumor cell line L929 (murine fibroblasts) to determine cytotoxicity with the MTT assay. 8-OH-β-lapachones (14a14c14d) presented best results, showing low IC50 values and high selectivity for HCT-116 and HL-60 tumor cells.

Synthesis and in silico and in vitro evaluation of trimethoxy-benzamides designed as anti-prion derivatives

Abstract

Transmissible spongiform encephalopathies (TSEs), also known as prion diseases, are neurodegenerative disorders which affect mammals, including the human species, and arise after the conversion of the monomeric cellular prion protein (PrPC) into the aggregated scrapie form (PrPSc). There is no therapy to treat TSEs and the identification of compounds that bind PrPC, preventing its conversion into PrPSc, is a viable therapeutic strategy. We designed and synthesized six novel trimethoxy-benzamide compounds as anti-prion drug candidates. Molecular docking analyses predicted that all the derivatives bind to a hotspot region located in the PrP globular domain with very similar spatial orientation and interaction mode. Although none of the analogs inhibited in vitro-aggregation of recombinant PrP (rPrP) in a cell-free conversion assay, the RT-QuIC, compound 8a accelerated rPrP conversion into PrPSc-like species. STD-NMR and ITC analyses indicated that both 8a and 8b bind to rPrP90–231. These analogs were toxic to PrPSc-infected cell lines, hence we could not assess their anti-prion activity by using this cellular approach, although this toxicity was cell line-dependent. These results point out that the 4-amino-quinoline trimethoxy-benzamide scaffold described herein represents a novel chemical pattern useful as a starting point for future structural optimization in the design of PrP ligands with improved affinity and safety profiles.

Chroman-4-one hydrazones derivatives: synthesis, characterization, and in vitro and in vivo antileishmanial effects

Abstract

In searching for better therapeutic alternatives to treat cutaneous leishmaniasis (CL), this study aimed to obtain and evaluate the efficacy and toxicity of new chroman-4-one hydrazones derivatives. Compounds were prepared and characterized, and then transformed into hydrazonas for molecular optimization. Their cytotoxicity was tested in different cell types using an in vitro MTT assay and the efficacy was evaluated using an in vitro macrophage intracellular amastigotes of Leishmania (Viannia) panamensis and L. (V) braziliensis by flow cytometry. The therapeutic effect of two formulations of chroman-4-one hydrazones on the CL induced by L. (V) braziliensis in golden hamsters was determined according to the size of lesions after treatment. The effect of these compounds in the production of inflammatory mediators and cell migration was also determined by in vitro assays using human fibroblasts models. Neither cytotoxicity nor genotoxicity was observed. The benzoic acid hydrazone derivative 2-(2,3-dihydro-4H-1-benzopyran-4-ylidene) hydrazide (4), produced a higher percentage of clinical cures, followed by benzoic acid, 2-(2,3-dihydro-4H-1-benzothiopyran-4-ylidene) hydrazide (3), while benzoic acid, 2-(2,3-dihydro-1,1-dioxide-4H-1-benzothiopyran-4-ylidene) hydrazide (5) and 4-pyridinecarboxylic acid, 2-(4H-1-benzopyran-4-ylidene) hydrazide (6) caused a poor therapeutic response. The compound 4 also showed an effect in the inflammatory and fibroblast migration processes. In conclusion, this is the first report of antileishmanial activity combined with inflammatory and wound healing properties. Results obtained here suggest that this strategy could be a good alternative for development of new drugs for the treatment of CL.

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