Chemical composition and antioxidant activities of different parts of Ficus sur

Introduction: Ficus sur is a plant widely used in traditional pharmacopoeia in Togo. So, this study aimed the assessment of antioxidant properties and identification of some compounds from the ethanolic extracts of different parts of the plant (leaves, fruits, roots, and barks). Methods: The phenolic and flavonoid contents of the ethanolic extracts of different organs of Ficus sur were assessed using conventional known methods. The DPPH radical scavenging and the ferric-reducing antioxidant power (FRAP) assays were used to highlight the antioxidant activities. The different extract samples were also analysed by liquid chromatography coupled to a quadrupole-time of flight mass detector (ESI-QTOF). Results: Total phenolic contents (TPCs) for 1 mg of dry extract ranged from 489.40 ± 7.48 μg GAE (gallic acid equivalents) for the bark to 62.34 ± 2.66 μg GAE for unripe fruits. The bark exhibited the highest flavonoid content, which was closed to 90.20 ± 3.72 μg QE (quercetin equivalents)/mg of dry extract. The radical scavenging activities of the bark and unripe fruits were 56.50 ± 0.29 and 7.3 ± 0.30 μg QE/mg of dry extract, respectively. In the same order, the FRAP values of the two organs were 104.57 ± 4.75 and 19.61 ± 0.22 μmol FeSO4 Eq/mg of dry extract. Many compounds including notoginsenoside R10; 4’,5,7-trihydroxyflavan-3-ol; catechin; and boviquinone 4 were identified. Conclusion: The various organs of Ficus sur are a source of bioactive compounds especially phenolic compounds and flavonoids with antioxidant activit

A significant antihypertensive effect of Holarrhena floribunda supported by an exploratory phytochemical study

Introduction: Holarrhena floribunda (G.Don) T.Durand & Schinz is a tree that can grow up to 25 m with white latex in its organs. The bark of this plant is commonly used in traditional medicine to treat dysentery, diarrhea, diabetes, malaria, and high blood pressure. In this study, phytochemical groups were widely investigated on trunk bark as well as on leaves of H. floribunda harvested in Danyi (Togo). Antioxidant activity and antihypertensive properties of the plant extracts were also evaluated on sound guinea pigs. Methods: The hydro-ethanolic extract of the trunk bark was prepared and antioxidant activity was evaluated via the DPPH radical-scavenging and the ferric-reducing antioxidant power (FRAP) methods, and via the determination of the total phenolics content. This hydro-ethanolic extract was used to assess the plant extract effect on blood pressure of sound guinea pigs. Results: So, phytochemical screening revealed that H. floribunda contained most of the phytochemical groups. The 50% inhibitive concentration of that extract by DPPH was 29.80 ± 0.001 μg/mL. The equivalent of Fe2+ by FRAP was 1009.9 ± 0.6 μmol/g of dry extract. The content of phenolic compounds was 139 ± 0.053 mg GAE (gallic acid equivalents)/g of dry extract. Intravenous injection of the extract (10, 20, 40, 80 mg/kg) via the invasive method in guinea pigs under normal strain caused a decrease in diastolic blood pressure, systolic blood pressure, and so in mean arterial pressure (MAP) by dose cumulative and time-dependent. Conclusion: The results show that hydro-ethanolic extract of H. floribunda trunk bark has antihypertensive and antioxidant properties. This might be the reason for the use of that extract for the treatment of hypertension in traditional medicin

A Comparative Study of the Chemical Composition of the Extracts from Leaves, Stem Bark, and Root Bark of Cassia sieberiana: Antibacterial Activities

In Togo, the abusive use of the root of Cassia sieberiana D.C. in traditional medicine, contributes gradually to the rarefaction of the species. The general objective of this study is to promote the use of vital organs of Cassia sieberiana in traditional medicine in Togo. The identification of secondary metabolites of the extracts (cyclohexane, dichloromethane and methanol) was carried out by GC-MS and by CL-MS / MS. The antibiotic susceptibility test was performed according to the well diffusion method and the MICs and MBCs according to the tube dilution method. Compounds such as sitosterol α-acetate, β-sitosterol, emodin, chaetochromine, luteolin, (±) -catechin, naringenin 5-O-rhamnoside, guibourtinidol- (4 alpha-> 6) -catechin and (-) - epiafzelechin are found in the root and in the stem bark. The identified molecules give the different methanolic extracts, an antibacterial effect on all the germs tested. At the end of this study, it appears that the chemical composition of the stem bark is almost similar to that of the root bark. The leaves would be better placed for the treatment of bacteria tested

Metal-Free Addition of Boronic Acids to Silylnitronates

International audienceWe report for the first time a metal-free addition of boronic acids to silylnitronates to afford oxime derivatives through aryl transfer on the carbon nitrogen double bond. A reaction mechanism has been proposed in relation with a DFT study on the key aryl transfer. This arylation process is effective for cycloalkenyl nitro derivatives leading to oximes that may be oxidatively converted into 3-arylisoxazole derivatives

A significant antihypertensive effect of Holarrhena floribunda supported by an exploratory phytochemical study

Introduction: Holarrhena floribunda (G.Don) T.Durand & Schinz is a tree that can grow up to 25 m with white latex in its organs. The bark of this plant is commonly used in traditional medicine to treat dysentery, diarrhea, diabetes, malaria, and high blood pressure. In this study, phytochemical groups were widely investigated on trunk bark as well as on leaves of H. floribunda harvested in Danyi (Togo). Antioxidant activity and antihypertensive properties of the plant extracts were also evaluated on sound guinea pigs. Methods: The hydro-ethanolic extract of the trunk bark was prepared and antioxidant activity was evaluated via the DPPH radical-scavenging and the ferric-reducing antioxidant power (FRAP) methods, and via the determination of the total phenolics content. This hydro-ethanolic extract was used to assess the plant extract effect on blood pressure of sound guinea pigs. Results: So, phytochemical screening revealed that H. floribunda contained most of the phytochemical groups. The 50% inhibitive concentration of that extract by DPPH was 29.80 ± 0.001 μg/mL. The equivalent of Fe2+ by FRAP was 1009.9 ± 0.6 μmol/g of dry extract. The content of phenolic compounds was 139 ± 0.053 mg GAE (gallic acid equivalents)/g of dry extract. Intravenous injection of the extract (10, 20, 40, 80 mg/kg) via the invasive method in guinea pigs under normal strain caused a decrease in diastolic blood pressure, systolic blood pressure, and so in mean arterial pressure (MAP) by dose cumulative and time-dependent. Conclusion: The results show that hydro-ethanolic extract of H. floribunda trunk bark has antihypertensive and antioxidant properties. This might be the reason for the use of that extract for the treatment of hypertension in traditional medicine

Identification de deux phytostérols biologiquement actifs de l’extrait cyclohexanique des feuilles de <i>Ficus sur</i> (Moraceae)

Ficus sur est une plante alimentaire couramment utilisée en médecine traditionnelle au Togo. Elle a cependant fait l’objet de très peu d’études phytochimiques. Le présent travail a pour but de valoriser cette espèce à travers l’identification continue de ses métabolites. Ainsi, l’extraction cyclohexanique au Soxhlet a été réalisée sur les feuilles de Ficus sur. Cet extrait cyclohexanique obtenu a été ensuite fractionné puis purifié par chromatographie sur colonne de gel de silice. L’identification des composés a été réalisée par GC-MS, précédée quelquefois d’une étape de dérivatisation. Treize fractions (A1 à A13) ont été obtenues du fractionnement de cet extrait. Après deux purifications successives de la fraction A5, deux sous-fractions A5.1 et A5.2 ont été obtenues. Le spectre de masse d’un composé de A2 présente un pic moléculaire à m/z 426 et des pics fragments [M-69]+, [M-154]+, [M-169]+, [M-197]+, [M-208]+ et [M-219]+ caractéristique du taraxastérol. Pour A5.2 dérivatisée, un composé présente un spectre de masse de pic moléculaire à m/z 486 et des pics fragments [M-90]+, [M-129]+ et [M-357]+ propres au β-sitostérol triméthylsilyl éther dérivé du β-sitostérol. La présence de ces deux phytostérols bioactifs serait un atout majeur dans l’usage thérapeutique de cette plante.© 2017 International Formulae Group. All rights reserved.Mots clés: Ficus sur, GC-MS, taraxastérol, β-sitostérolEnglish Title: Identification of two bioactive phytosterols of the cyclohexane extract of Ficus sur (moraceae) leavesEnglish AbstractFicus sur is a food plant commonly used in traditional medicine in Togo. However, few phytochemical studies of this species are available. This work aims at contributing to the enhancement of this approach through an identification of its metabolites. The leaves of Ficus sur were then extracted with cyclohexane using soxhlet. The obtained cyclohexane extract was fractionated and purified by chromatography on silica gel column. Identification of the compounds was carried out by GC-MS, sometimes preceded by a derivatization step. Thirteen fractions (A1 to A13) were obtained from the fractionation of this extract. After two successive purifications of the fraction A5, two subfractions A5.1 and A5.2 were obtained. The mass spectrum of a compound of A2 has a molecular peak at m/z 426 and peaks [M-69]+, [M-154]+, [M-169]+, [M-197]+, [M-208]+ and [M-219]+ characteristic of taraxasterol. For the derivatized fraction A5.2, a compound has a mass spectrum of molecular peak at m/z 486 and peaks [M-90]++ and [M-357]+ characteristic of β-sitosterol trimethylsilyl ether derived from β-sitosterol. The presence of these two bioactive phytosterols would be a major asset in the therapeutic use of this plant.© 2017 International Formulae Group. All rights reserved.Keywords: Ficus sur, GC-MS, taraxasterol, β-sitostero