Cholinesterase Inhibitors from an Endophytic Fungus Aspergillus niveus Fv-er401: Metabolomics, Isolation and Molecular Docking.

Alzheimer's disease poses a global health concern with unmet demand requiring creative approaches to discover new medications. In this study, we investigated the chemical composition and the anticholinesterase activity of Aspergillus niveus Fv-er401 isolated from Foeniculum vulgare (Apiaceae) roots. Fifty-eight metabolites were identified using UHPLC-MS/MS analysis of the crude extract. The fungal extract showed acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory effects with IC50 53.44 ± 1.57 and 48.46 ± 0.41 µg/mL, respectively. Two known metabolites were isolated, terrequinone A and citrinin, showing moderate AChE and BuChE inhibitory activity using the Ellman's method (IC50 = 11.10 ± 0.38 µg/mL and 5.06 ± 0.15 µg/mL, respectively for AChE, and IC50 15.63 ± 1.27 µg/mL and 8.02 ± 0.08 µg/mL, respectively for BuChE). As evidenced by molecular docking, the isolated compounds and other structurally related metabolites identified by molecular networking had the required structural features for AChE and BuChE inhibition. Where varioxiranol G (-9.76 and -10.36 kcal/mol), penicitrinol B (-9.50 and -8.02 kcal/mol), dicitrinol A (-8.53 and -7.98 kcal/mol) and asterriquinone CT5 (-8.02 and -8.25 kcal/mol) showed better binding scores as AChE and BuChE inhibitors than the co-crystallized inhibitor (between -7.89 and 7.82 kcal/mol) making them promising candidates for the development of new drugs to treat Alzheimer's.

Identification of Antimicrobial Metabolites from the Egyptian Soil-Derived Amycolatopsis keratiniphila Revealed by Untargeted Metabolomics and Molecular Docking.

Actinomycetes are prolific producers of bioactive secondary metabolites. The prevalence of multidrug-resistant (MDR) pathogens has prompted us to search for potential natural antimicrobial agents. Herein, we report the isolation of rare actinobacteria from Egyptian soil. The strain was identified as Amycolatopsis keratiniphila DPA04 using 16S rRNA gene sequencing. Cultivation profiling, followed by chemical and antimicrobial evaluation of crude extracts, revealed the activity of DPA04 ISP-2 and M1 culture extracts against Gram-positive bacteria. Minimum inhibitory concentrations (MIC) values ranged from 19.5 to 39 µg/mL. Chemical analysis of the crude extracts using ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF) led to the identification of 45 metabolites of different chemical classes. In addition, ECO-0501 was identified in the cultures with significant antimicrobial activity. Multidrug resistance in Staphylococcus aureus is reported to be related to the multidrug efflux pump (MATE). ECO-0501 and its related metabolites were subjected to molecular docking studies against the MATE receptor as a proposed mechanism of action. ECO-0501 and its derivatives (AK_1 and N-demethyl ECO-0501) had better binding scores (-12.93, -12.24, and -11.92 kcal/mol) than the co-crystallized 4HY inhibitor (-8.99 kcal/mol) making them promising candidates as MATE inhibitors. Finally, our work established that natural products from this strain could be useful therapeutic tools for controlling infectious diseases.

In-vivo Anti-inflammatory Activity of Hydrocotyle umbellata L. aerial parts and Isolation of the Main Phytochemicals.

Hydrocotyle umbellata L. (Family Araliaceae) populary known as Acaricoba, is indicated in folk medicine for treatment of several inflammatory disorders. The goal of the present study is to evaluate the anti-inflammatory activity of the defatted ethanolic extract (DEE) of the aerial parts using carrageenan-induced rat paw oedema method. The levels of the pro-inflammatory cytokine interleukin-6 (IL-6) and the inflammatory mediator prostaglandin E2 (PGE2) were assessed using ELISA. The DEE at dose level 100 mg/kg showed significant decrease in oedema volume after 2 and 3 h, equivalent to 70.75% and 95.92% of the activity of the standard anti-inflammatory indomethacin, respectively. DEE significantly decreased the concentrations of the excessively produced IL-6 and PGE2 (24 ± 2.1 and 2374 ± 87 pg/mL compared to 16 ± 2 and 2419 ± 95 pg/mL induced by indomethacin). Chemical investigation was carried out to isolate and identify the bioactive compounds that might be responsible for this activity. The total phenolic (79.28 ± 0.1 mg) and total flavonoid (57.99 ± 0.1 mg) contents of the DEE were quantified spectrophotometricaly and expressed as gallic acid and rutin equivalents/g dry weight, respectively. The DEE was subjected to further fractionation using solvents of increasing polarities. Purification of the ethyl acetate fraction using different chromatographic techniques led to the isolation of five compounds, which were identified through 1D and 2D and UV/Vis spectral data. The five compounds were: quercetin, avicularin, quercitrin, hyperoside, and neochlorogenic acid. Several biological studies confirmed the important role of caffeoyl quinic acid and quercetin derivatives as anti-inflammatory bioactive compounds.

Anticancer and antioxidant tannins from Pimenta dioica leaves.

Two galloylglucosides, 6-hydroxy-eugenol 4-O-(6'-O-galloyl)-beta-D-4C1-glucopyranoside (4) and 3-(4-hydroxy-3-methoxyphenyl)-propane-1,2-diol-2-O-(2',6'-di-O-galloyl)-beta-D -4C1-glucopyranoside (7), and two C-glycosidic tannins, vascalaginone (10) and grandininol (14), together with fourteen known metabolites, gallic acid (1), methyl gallate (2), nilocitin (3), 1-O-galloyl-4,6-(S)-hexahydroxydiphenoyl-(alpha/beta)-D-glucopyranose (5), 4,6-(S)-hexahydroxydiphenoyl-(alpha/beta)-D-glucopyranose (6), 3,4,6-valoneoyl-(alpha/beta)-D-glucopyranose (8), pedunculagin (9), casuariin (11), castalagin (12), vascalagin (13), casuarinin (15), grandinin (16), methyl-flavogallonate (17) and ellagic acid (18), were identified from the leaves of Pimenta dioica (Merr.) L. (Myrtaceae) on the basis of their chemical and physicochemical analysis (UV, HRESI-MS, 1D and 2D NMR). It was found that 9 is the most cytotoxic compound against solid tumour cancer cells, the most potent scavenger against the artificial radical DPPH and physiological radicals including ROO*, OH*, and O2-*, and strongly inhibited the NO generation and induced the proliferation of T-lymphocytes and macrophages. On the other hand, 3 was the strongest NO inhibitor and 16 the highest stimulator for the proliferation of T-lymphocytes, while 10 was the most active inducer of macrophage proliferation.

Polyhydroxy Sterols Isolated from the Red Sea Soft Coral. Lobophytum crassum and their Cytotoxic Activity.

One new (1) together with four known sterols (2 - 5) and a sesquiterpene (6) were isolated from a polar extract of the Red Sea soft coral Lobophytum crassum. The compounds were identified as 24-methylenecholest-5-ene-lα,3ß,1lα-triol 1-acetate (1), 24-methylenecholest-5-ene-la,3ß,llα-triol (2), 24- methylenecholest-5-ene-3ß-ol (3), 24-methylenecholestane-la,3ß,5α,6ß,I la-pentol (4), 24-methylenecholestane-3ß,5α,6ß-triol (5) and alismoxide (6) based on extensive NMR analysis. The cytotoxicity of compounds 1 - 6 was evaluated in vitro using three human cancer cell lines viz., HepG2, Hep-2 and HCT-I 16. Compound 1 showed selective cytotoxic activity against HepG2, while 3 exhibited cytotoxicity against all tested cell lines.

3-Keto-22-epi-28-nor-cathasterone, a brassinosteroid-related metabolite from Cystoseira myrica.

Bioassay-guided purification of an ethanolic extract of Cystoseira myrica against HEPG-2 (liver) and HCT116 (colon) human cancer cell lines led to the isolation of 3-keto-22-epi-28-nor-cathasterone, 1 and cholest-4-ene-3,6-dione, 2. This finding allowed us to report for the first time that a brassinosteroid-related metabolite occurs in seaweed. These compounds showed activity in the range of 12.38-1.16 microM with selective activity of compound 2 to liver cancer cell lines.

1H-NMR assay of papaverine hydrochloride and formulations.

A precise and specific 1H-NMR method has been developed for the assay of papaverine hydrochloride (1) as a bulk drug, as well as in tablet and injection dosage forms. The assay depends upon the integration of the 12 protons of the four methoxy groups of 1 relative to that of the three methyl protons of acetanilide (internal standard). In addition to the accurate quantitative determination of 1, the method provides a specific means of identifying 1 as well as detecting other alkaloids or impurities.