Isolation and structure elucidation of polyphenols from Loranthus micranthus Linn. parasitic on Hevea brasiliensis with antiinflammatory property

The present study was carried out to evaluate the anti-inflammatory activities of polyphenols isolated from the leaves of mistletoe (Loranthus micranthus Linn.) parasitic on Hevea brasiliensis. The anti-inflammatory properties of the isolated compounds were evaluated on the basis of their ability to inhibit the production of nitric oxide (NO) and tumuor necrosis factor-α (TNF-α) in lipopolysaccharide (LPS) activated RAW 264.7 mouse macrophages. Semipreparative HPLC separation of the ethyl acetate (EtOAc) and butanol (n-BuOH) fractions of the leaves of mistletoe (Loranthus micranthus Linn) parasitic on Hevea brasiliensisled to the isolation of four polyphenols: 3-O-(3,4,5-trimethoxybenzoyl)-(-)-epicatechin (TMECG) (1);(-)-epicatechin-3-O-(3′′-O-methyl)-gallate (ECG3′′Me) (2); rutin (3) and peltatoside (4). Compounds 1-4 were isolated for the first time from this plant while 1 was isolated for the first time in nature. These compounds (1-4) were readily identified by comparison of their spectroscopic data with those reported in the literature. The polyphenols proved to have anti-inflammatory activity as evidenced by the suppression of inducible nitric oxide (iNO) and cytokine (TNF-α) levels in the culture supernatant of lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophages. However, the study showed that the quercetin diglycosides showed stronger inhibition of proinflammatory mediators than the epicatechin derivates. These data provide evidence that polyphenolic compounds isolated from the mistletoe parasitic on Hevea brasiliensis may contribute to its anti-inflammatory properties by inhibiting the expression of inducible nitric oxide and proinflammatory cytokines such as tumour necrosis factor-α

Antioxidant Activities of the Leaf Extract and Fractions of Dryopteris filix-mas (L.) Schott could be Attributed to The Abundance of Polyphenol Compounds

Dryopteris filix mas (D filix-mas) is wildly used in ethnomedicine for the management of rheumatoid arthritis, wounds and other diseases. We investigated the anti-oxidant activities of its leaf extract, and chromatographic fractions. The ethanol leaf extract was partitioned into four fractions; n-hexane, ethyl acetate, n-butanol and water. Ferric reducing anti-oxidant power (FRAP), 1, 1-diphenyl-2-picrylhydrazil (DPPH) and nitric oxide (NO) scavenging in vitro assays were carried out on the extract and fractions at 6.25, 12.5, 25, 50, 100, 200, 400 and 800 µg/mL. The most active fraction (ethyl acetate fraction) was further purified using chromatographic techniques to isolate its major compound whose structure was elucidated using ID nuclear magnetic resonance (NMR) and mass spectrometry. The ethyl acetate fraction produced the highest free radical scavenging activity among the other fractions. The fraction (VLC-E7) from which the bioactive compound, quercetin-3-O-αL-rhamnopyranoside, was isolated had the best FRAP and DPPH scavenging activities with EC50 and IC50 values of 88.81 ± 3.41 and 26.87 ± 0.24 respectively more than the ethyl acetate fraction. This study revealed that the polyphenol flavonoid, quercetin-3-O-αL-rhamnopyranoside could be responsible for antioxidant activity of ethno-medicinal property of D filix-mas leaf

Mosquito repellent activity of Spondias mombin L. (Family Anacardiaceae) crude methanol extract and fractions against Aedes aegypti (L.)

The aim was to determine the repellent activities of creams formulated with different extract/fractions of Spondias mombin L. against female Aedes aegypti (L.). The repellent activity was carried out using blood-starved female mosquitoes inside net cages in the laboratory condition following World Health Organization protocol at three different concentrations, viz. 1, 2, and 4 mg/cm2 in the exposed area of human hands. Acetone together with white soft paraffin served as negative control and 12 % Odomos was used as the positive control. The cream formulations gave good protection against the mosquito bites and the repellent activity was dependent on the strength of the extract and fractions. Among the tested formulations, the maximum protection time was observed in MCE (180 min), HF (180 min) and DF (180 min) at 1 mg/cm2. From the results, it was clear that the MCE, HF and DF formulations can be used as natural mosquito repellents as alternatives to Odomos

Mosquito repellent activity of <i>Spondias mombin</i> L. (Family Anacardiaceae) crude methanol extract and fractions against <i>Aedes aegypti </i> (L.)

240-244The aim was to determine the repellent activities of creams formulated with different extract/fractions of Spondias mombin L. against female Aedes aegypti (L.). The repellent activity was carried out using blood-starved female mosquitoes inside net cages in the laboratory condition following World Health Organization protocol at three different concentrations, viz. 1, 2, and 4 mg/cm2 in the exposed area of human hands. Acetone together with white soft paraffin served as negative control and 12 % Odomos was used as the positive control. The cream formulations gave good protection against the mosquito bites and the repellent activity was dependent on the strength of the extract and fractions. Among the tested formulations, the maximum protection time was observed in MCE (180 min), HF (180 min) and DF (180 min) at 1 mg/cm2. From the results, it was clear that the MCE, HF and DF formulations can be used as natural mosquito repellents as alternatives to Odomos

In vitro and in vivo antioxidant potentials of Alchornea floribunda leaf extract, fractions and isolated bioactive compounds

Objective: Alchornea floribunda leaves are widely used in ethnomedicine for the management of immuno-inflammatory disorders. We investigated the in vivo and in vitro antioxidant activity of the leaf extract, fractions and isolated compounds of A. floribunda.Materials and Methods: The ethyl acetate fraction of the methanol leaf extract was subjected to several chromatographic separations to isolate compounds 1-4. The structures of the isolated compounds were elucidated by a combination of 1D and 2D NMR and mass spectrometry. Oxidative stress was induced with carbon tetrachloride (CCl4). Further analysis on the isolated phenolic compounds were done using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and hydrogen peroxide scavenging activity tests.Results: The ethyl acetate fraction at 200 mg/kg produced significant (

New neolignan glycoside and an unusual benzoyl malic acid derivative from <i>Maytenus senegalensis</i> leaves

<div><p>Further investigation of the methanol leaf extract of <i>Maytenus senegalensis</i> led to the isolation of six compounds, including mayselignoside (<b>1</b>) and an unusual benzoyl malic acid derivative, benzoyl <i>R</i>-(+)-malic acid (<b>2</b>). Two known lignan derivatives (+)-lyoniresinol (<b>3</b>) and ( − )-isolariciresinol (<b>4</b>), a known neolignan derivative dihydrodehydrodiconiferyl alcohol (<b>5</b>) and the triterpenoid, β-amyrin (<b>6</b>) were also isolated. The structures of these compounds were elucidated by a combination of 1D and 2D NMR and mass spectroscopy. All compounds were tested for cytotoxicity against mouse lymphoma cell line (L5178Y) and for antimicrobial activity against strains of bacteria and fungi. None of the compounds showed promising cytotoxic and/or antimicrobial activities.</p></div