Anti-yeast activity of extracts and fractions from Uvariodendron calophyllum (Annonaceae)

The resistance to available antifungals highlights the urgent need for innovative drugs to treat yeasts infections. This study aimed at evaluating the activity of extracts and fractions from Uvariodendron calophyllum against pathogenic yeasts. The ethanolic and aqueous extracts obtained by maceration were liquidliquid- partitioned using organic solvents and screened against isolates of Candida albicans, Candida glabrata, Candida parapsilosis, Cryptococcus neoformans and Candida albicans reference strains NR-29445, NR-29444, NR-29451, and NR-29450 from BEI Resources using the broth micro-dilution method. Time kill kinetic, inhibition of germ-tube, filamentation and chlamydosporulation, and biofilm formation were assessed using the best sub-fraction. Overall, the most interesting sub-fraction (FS: 237–253) showed an MIC value of 0.0625 mg/mL with cidal effect against C. albicans NR-29450 and NR-29445 at 0.25 mg/mL after 12-16 hours and 24 hours respectively. Moderate inhibitory effects were observed at 0.25 mg/mL against germ-tube formation, filamentation and chlamydosporulation of all C. albicans strains. Also, very moderate inhibition of biofilm formation by C. albicans NR-29450 at 0.25 mg/mL was obtained. The results obtained support U. calophyllum as a potential source of compounds with anti-yeast activity. Further studies will confirm its potential as source of anti-yeast drugs.© 2015 International Formulae Group. All rights reserved.Keywords: Uvariodendron calophyllum, anti-yeasts activity, time kill kinetics, biofil

A new isoquinoline and ceramide from the stem barks of Discoglypremna caloneura (Pax) Prain (Euphorbiaceae) with antiproteinase and cytotoxic activities.

peer reviewedTwo new compounds, an isoquinoline (1) and caloneuramide (2), a ceramide were isolated from the stem bark of Discoglypremna caloneura together with seven known compounds namely aurantiamide acetate (3), acetylaleuritolic acid (4), 3α-hydroxylaleuritolic acid 2α-p-hydroxybenzoate (5), mixture of stigmasterol (6) and β-sitosterol (7), mixture of 7-oxo-stigmasterol (8) and 7-oxo-β-sitosterol (9). Their structures were determined based on data from literature and spectroscopic methods. Derivatization reactions on the isoquinoline led to two new compounds, the methylated (10) and acetylated (11) derivatives. Some compounds and extracts were evaluated for their cytotoxic and antiproteinase activity. Antiproteinase effect of compounds 1, 10 and 11 exhibited IC(50) values of 10.77, 1.19 and 3.61 μg/mL respectively; significantly low compared to the standard drug, acetyl salicylic acid (IC(50) = 20.28 μg/mL). Ethyl acetate and methanol extract exhibited moderate cytotoxicity activity on Chang liver cells with CC(50) values of 167.90 ± 2.20 and 106.30 ± 2.03 μg/mL compared to the reference drug cucurmin (CC(50) = 11.05 ± 1.04 μg/mL)

Antiradical Activity, Total Phenolic and Flavonoid Content of Extracts from the Stem Bark of Pterocarpus erinaceus

Abstract: In this study, radical scavenging activity, total phenolic and flavonoid contents of hexane, ethyl acetate, nbutanol and methanol extracts of the stem bark of Pterocarpus erinaceus were investigated. Antioxidant activity was assessed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-benzothiazoline-6-sulfonic acid) (ABTS) assay. Total phenolic and flavonoid contents were evaluated with Folin-Ciocalteu and aluminium chloride colorimetric method respectively. Methanol extract showed the best antioxidant activity with the highest total flavonoid content (396.61±3.48 mgE Cat/1g DE) followed by n-butanol extract (263.63±5.44 mgECat/1g DE) and ethyl acetate extract (224.71±7.32 mgECat/1g DE). However, the n-butanol extract showed a highest phenolic content (490.03±4.02 mgEAA/1g DE) than the methanol extract (450.50±1.52 mgEAA/1g DE). These findings showed increase in antioxidant activity directly proportional to increase in extracting solvent's polarity and flavonoid content

SARS-CoV-2 main protease inhibitors from the stem barks of Discoglypremna caloneura (Pax) Prain (Euphorbiaceae) and Pterocarpus erinaceus Poir (Fabaceae) and their molecular docking investigation

Abstract The main viral protease (Mpro) of SARS-CoV-2 provides an excellent target for antivirals, due to its essential and conserved function in the viral replication cycle. We reported in this study, the SARS-CoV-2 main protease inhibitory effect of twelve compounds isolated from D. caloneura and P. erinaceus together with four derivatives. Among the effectively tested samples, two derivatized compounds displayed significant improvement on the activity from the starting material, friedelin (1) through the acetoreduced (2) to the acetoxy product (3) with respective IC50 values of 42.89, 29.69 and 19.39 µg/mL. The latter displayed the highest activity although lower as compared to that of baicalein, the positive control with IC50 0.41 µg/mL. The molecular docking study showed that an increase in the number of hydrogen bonds between compounds and active site of Mpro resulted in increased inhibition. Graphical Abstrac