In vitro screening of Strychnos species for antiplasmodial activity

Peer reviewe

Antioxidant fractions and phenolic constituents from leaves of Pluchea carolinensis and Pluchea rosea

peer reviewedAbstract: Objective: To evaluated the antioxidant potential of several polar fractions of P. carolinensis and P. rosea as well as pure chemicals, some of them quantified in both species by HPLC. Methods: The antioxidant potential of polar fractions and pure chemicals were assayed by 2,2-diphenyl-1-picrylhydrazyl and oxygen radical potential methods. The phenolic content was performed by using Folin–Ciocalteu’s reagent. Specific phenolic acids and flavonoids were quantified by DAD-RP-HPLC. Results: The highest DPPH antioxidant potential expressed in mg TE/gDE were frequently measured in fractions from n-butyl alcohol i.e 2 (192.1 ± 0.3); 6 (181.0 ± 0.1) of P. carolinensis and in fraction 7 (188.1 ± 5.5) of P. rosea while for ORAC (mg TE/gDE) assay fraction 2 (543.0 ± 64.6) and 4 (501.4 ± 49.7) of P. carolinensis and 3 (401.3 ± 16.1) and 6 (401.3 ± 16.1) of P. rosea showed the best results. Some flavonoids and phenolic acids were also assayed; all of them showed highest Oxygen radical absorbance capacity values. Conclusion: We report the antioxidant potential of polar fractions, as well as of some pure phenolics responsible of the antioxidant potential. Some phenolics were identified and quantified for the first time in both species. Apparently, caffeoylquinic acid derivatives contribute more significant to the total antioxidant potential of the extracts

Steroidal glycosides from the flowers of Allium leucanthum

Furostanol and spirostanol glycosides 1 and 2 were isolated from the flowers of Allium leucanthum, a Caucasian endemic species that grows in Georgia. The structures were established on the base of chemical evidence and spectral analyses ( (1) H, (13) C NMR, (1) H- (1) H COSY, (1) H- (13) C COSY, HMBC, and HR-MS) data. Compound 1 (leucofuranoside A) was reported for the first time and was identified as 26-O-beta-Dglucopyranosyl-(25R)-5 alpha-furostane-3 beta,6 beta-diol-3-O-beta-D-glucopyranosyl-(1 -> 2)-O-beta-D-xylopyranosyl-(1 -> 3)-O-beta-D-glucopyranosyl-(1 -> 4)-beta-D-alactopyranoside. Compound 2 was identified as (25R)-5 alpha-spirostane-3 beta,6 beta-diol-3-O-beta-D-glucopyranosyl-(1 -> 2)-beta-D-glucopyranosyl-(1 -> 4)-beta-D-galactopyranoside and described for the first time in the genus Allium

Strychnohexamine from Strychnos icaja; the first naturally occurring indolomonoterpenoid trimeric alkaloid

Peer reviewe

In vitro and in vivo antimalarial and cytotoxic activity of five plants used in Congolese traditional medicine.

peer reviewedAIM OF THE STUDY: The in vitro antiplasmodial activity and cytotoxicity of methanolic and dichloromethane extracts from five Congolese plants were evaluated. The plants were selected following an ethnobotanical survey conducted in D.R. Congo and focusing on plants used traditionally to treat malaria. The in vivo antimalarial activity of aqueous and methanolic extracts active in vitro was also determined in mice infected by Plasmodium berghei berghei. MATERIALS AND METHODS: The growth inhibition of Plasmodium falciparum strains was evaluated using the measurement of lactate dehydrogenase activity. The extracts (aqueous, CH(3)OH, EtOH and CH(2)Cl(2)) were prepared by maceration and tested in vitro against the 3D7 (chloroquine sensitive) and W2 (chloroquine resistant) strains of Plasmodium falciparum and against the human normal fetal lung fibroblasts WI-38 to determine the selectivity index. Some extracts were also used at the dose of 300mg/kg to evaluate their activity in mice infected since 4 days by Plasmodium berghei. RESULTS: Two plants presented a very high activity (IC(50)10, Anisopappus chinensis). Anisopappus chinensis and Physalis angulata were also active in vivo

Isolation and Identification of Steroid and Flavonoid Glycosides from the Flowers of Allium gramineum

peer reviewedThe isolation and identification of β-sitosterol 3-O-β-glucopyranoside, quercetin 3-O-β-glucopyranoside, isorhamnetin 3,4'-di-O-β-glucopyranosideand isorhamnetin 3,7-di-O-β-glucopyranosidefrom the flowers of Allium gramineumthat growsin Georgia.The structures of isolated compounds havebeen determined by 1H and 13C nuclear magnetic resonance (NMR) Isolation and Identification of Steroid and Flavonoid Glycosides from the Flowers of Allium gramineum. Available from: https://www.researchgate.net/publication/305851744_Isolation_and_Identification_of_Steroid_and_Flavonoid_Glycosides_from_the_Flowers_of_Allium_gramineum [accessed Aug 5, 2016]