Phytochemical study, antioxidant and tyrosinase inhibitory activities of Pentzia monodiana Maire.

Chemical investigation of the aerial parts of Pentzia monodiana Maire led to the isolation and identification of one sesquiterpene lactone glucoside of the guaianolide type (dihydropseudoivalin-4-O-ß-d-glucopyranoside), along with nine known compounds including one diterpenoid, two sesquiterpenoids, three lignanes and three flavonoids. Their structures were established on the basis of spectroscopic analysis. All these compounds were evaluated for their DPPH radical scavenging and tyrosinase inhibitory activities. Only lignanes and flavonoids showed good to moderate DPPH radical scavenging activity with EC50 ranging from 10.6 to 47.5 µM. The new sesquiterpene lactone glucoside showed low tyrosinase inhibitory activity whereas the isolated lignanes and flavonoids exhibited a moderate activity with IC50 ranging from 45.4 to 97.2 µM).

New triterpenoid saponin from the aerial part of Abrus canescens Welw ex. Bak. (Fabaceae) and their antibacterial activities.

The chemical investigation of the aerial part of Abrus canescens led to isolation of a new triterpenoid glycoside named Canescensoside (1) and four known compounds including longispinogenin-3-O-ß-D-glucuronopyranoside (2), ß-sitosterol-3-O-ß-D-glucoside (3), apigenin-7-O-ß-D-glucopyranoside (4) and apigenin-7-O-[α-L-rhamnopyranosyl-(1→3)-ß-D-glucopyranoside] (5). Structures of compounds were assigned by interpretation of their spectral data, mainly 1D and 2D NMR, HRESIMS, and by comparison with the reported data. The MeOH extract, EtOAc and n-BuOH fractions as well as isolated compounds were tested for their antibacterial activities against four bacteria strains among which, two Gram-negative (Pseudomonas aeruginosa ATCC 76110 and Escherichia coli ATCC 8739) and two Gram-positive (Enterococcus faecalis ATCC 29212 and Staphylococcus aureus ATCC 25923) bacteria using the broth microdilution method. The MeOH extract and EtOAc fraction exhibited significant activities (MIC values ranging from 128 to 512 µg/mL) against all the tested bacteria. Compounds 2 and 3 showed the lowest MIC values of 55.47 and 50.40 µM, respectively.

A new acylated flavonol triglycoside and evaluation of the antioxidant activity of Astragalus armatus subsp. numidicus (Murb.) Emb. & Maire.

A new acylated flavonol triglycoside, quercetin-3-O-(5'-p-hydroxybenzoyl)-ß-D-apiofuranosyl-(1→2)[α-L-rhamnopyranosyl-(1→6)]-ß-D-galactopyranoside (1), was isolated from the aerial parts of Astragalus armatus subsp. numidicus (Murb.) Emb. & Maire as well as ten known compounds, one phenolic compound, one flavonol-aglycone and eight flavonol-glycosides distributed into two monoglycosides, three diglycosides and three triosides. Their structures were mainly determined by 1D- and 2D-NMR experiments (1H,13C, COSY, HSQC, HMBC). The chloroform, ethyl acetate, n-butanol and hydroethanol extracts were tested for their antioxidant activity using five methods (DPPH, ABTS, Reducing power, CUPRAC and Phenanthroline). The ethyl acetate extract was the most active in CUPRAC (A0.5: 50.28 ± 2.16 µg/mL), ABTS (IC50: 49.73 ± 1.55 µg/mL) and Reducing power (A0.5: 58.13 ± 4.35 µg/mL) assays, whereas the hydroethanol and n-BuOH exhibited the highest activity in the Phenanthroline assay (A0.5: 9.93 ± 0.16) and (A0.5: 10.27 ± 0.44 µg/mL), respectively.

A new triterpene saponin and known compounds from the polar extract of Salvia argentea L. and evaluation of their antioxidant activity.

A new triterpene saponin, 2, 3, 21, 23-tetrahydroxyolean-12-en-28-oic-acid-28-O-ß-D- glucosyl-(2''→1')-ß-D-glucoside (1), was isolated from the n-butanol extract of dried aerial parts of Salvia argentea L. (Lamiaceae) in addition to two known flavonoids, apigenin 7-O-ß-D-glucoside (2), threo-guaiacylglycerol 3-O-[6-O-p-hydroxybenzoyl]-ß-D-glucoside (3), luteolin 7-O-ß-D-glucoside (4), verbascoside (5) and rosmarinic acid (6). The structure elucidation of these compounds was based on analyses of spectroscopic data including 1D-, 2D-NMR and HR-ESI-MS techniques and by comparing their NMR data with those reported in the literature. Compound 6 exhibited the highest antioxidant activity in DPPH assay (IC50<3.00 µg/mL) which was better than the standards BHA, BHT, Trolox and ascorbic acid.

A new phenolic glycoside from the leaves of Flacourtia flavescens Willd.

Chemical study of the methanol extract from the leaves of Flacourtia flavescens led to the isolation of a new phenolic glucoside (1) along with fifteen known secondary metabolites namely shanzhiside methyl ester (2), aurantiamide acetate (3), caffeic acid methyl ester (4), caffeic acid (5), apigenin (6), luteolin (7), kaempferol (8), quercetin (9), gyrophoric acid (10), luteolin-7-O-ß-D-glucopyranoside (11), luteolin-4'-O-ß-D-glucopyranoside (12), kaempferol-7-O-α-L-rhamnopyranoside (13), kaempferol-3-O-ß-D-glucopyranosyl-(1→6)-O-α-L-rhamnopyranoside (14), kaempferol-3,7-O-α-L-dirhamnopyranoside (15) and (2S,3S,4R,8E)-2-((2'R)-2'-hydroxy-octadecanoylamino)-lignocerane-1,3,4-triol-8-ene (16). Their structures were elucidated by 1D and 2D NMR analysis and mass spectrometry. The extracts and the isolated compounds were evaluated for their antibacterial activities. The EtOAc extract was highly active (MIC = 32 and 64 µg/mL) against E. coli and E. faecalis, respectively. Compounds 1, 2, 2b, 5, 8, 9, and 12 (MIC = 16-32 µg/mL) were moderately active against some tested bacteria.

Triterpene and Steroids from Ludwigia abyssinica A. Rich (Onagraceae) Displayed Antimicrobial Activities and Synergistic Effects with Conventional Antibiotics.

Difficulties encountered in treating drug-resistant pathogens have created a need for new therapies. Synergistic combinations of antibiotics are considered as ideal strategies in combating clinical and multidrug-resistant (MDR) infections. In this study, the antimicrobial activities of triterpenes and steroids from Ludwigia abyssinica A. Rich (Onagraceae) and their combined effects with antibiotics were assessed. The associations between plant constituents and antibiotics were evaluated by determining their fractional inhibitory concentrations (FICs). Sitost-5-en-3ß-ol formiate (1), 5α,6ß-dihydroxysitosterol (2), and maslinic acid (3) were isolated from the L. abyssinica ethyl acetate (EtOAc) extract. The EtOAc extract, compounds 1, 2, and 3 (MIC = 16-128 µg/mL) would be the best antibacterial and antifungal agents. The antimicrobial activities of amoxicillin were relatively weak against MDR Escherichia coli and Shigella flexneri and significant against Staphylococcus aureus ATCC 25923. However, when used in association with plant constituents, it displayed an interesting synergistic effect. Among plant components-antibiotic combinations, the EtOAc extract and compound 1 (steroid) showed a synergistic effect with amoxicillin/fluconazole against all the tested microorganisms whereas the association of compound 3 (triterpenoid) and amoxicillin/fluconazole displayed an additive effect against Shigella flexneri and Escherichia coli and a synergistic effect on Staphylococcus aureus, Cryptococcus neoformans, Candida tropicalis, and Candida albicans ATCC 10231. Overall, the results of the present study demonstrated antibacterial and antifungal activities of extracts and compounds isolated from L. abyssinica. The findings of the current study also showed that the potency of antibiotics was improved when screened in combination with L. abyssinica components, supporting the drug combination strategy to combat antimicrobial resistance.

New diterpenoids and phenolic amides from Icacina mannii Oliv.

Fourteen undescribed compounds including five neoclerodanes (1-5), three labdanes (12-14), three pimarane (15-17) derivatives, one carbamate (24) and two clovamide-type amides (25 and 26), along with twenty-two known compounds (6-11, 18-23 and 27-36) were isolated from the tuber and stem of Icacina mannii. Their structures were elucidated by 1D and 2D NMR and HR-ESI-MS data analysis, and by comparing their NMR data with those of the literature.

A new flavonoid glycoside from the aerial parts of Diplotaxis erucoides (L.) DC. growing in Algeria.

The phytochemical study of the 70% ethanol extract of the aerial parts of Diplotaxis erucoides afforded one new flavonoid glycoside, namely kaempferol-3-O-[α-L-rhamnopyranosyl-(1→2)-ß-D-xylopyranoside]-7-O-α-L-rhamnopyranoside (1), named diploerucoside A and seven known compounds including one flavonoid (2), one phenolic glycoside (3), one monoterpene (4), one triterpene (5), one sitosterol (6) and two monoglycerolipids (7, 8). Their structures were established by extensive spectroscopic analysis including 1 D- and 2 D-NMR (1H, 13C, 1H-1H COSY, HSQC and HMBC), mass spectrometry (HR-ESI-MS) and by comparison with the data reported in the literature.

Triterpenoid saponins from Anagallis monelli ssp. linifolia (L.) Maire and their chemotaxonomic significance.

Thirteen undescribed triterpenoid saponins named monellosides A-M, were isolated from the aerial parts of Anagallis monelli ssp. linifolia (L.) Maire, together with ten known oleanane-type glycosides. Their structures were elucidated by 1D and 2D-NMR spectroscopy (COSY, TOCSY, HSQC, HMBC and ROESY) as well as high resolution mass spectrometry (HR-ESI-MS) and acid hydrolysis. Monellosides A-M have a carbohydrate chain linked on the C-3 of the aglycone with a common ß-d-glucopyranosyl-(1 â†’ 4)-α-l-arabinopyranosyl sequence which was further glycosylated by a glucose and/or a xylose. The sequence ß-d-xylopyranosyl-(1 â†’ 2)-ß-d-glucopyranosyl-(1 â†’ 4)-[ß-d-glucopyranosyl-(1 â†’ 2)-]α-l-arabinopyranosyl was common to all the 13,28-epoxy-oleanane core skeleton except one compound. In order to discuss the reclassification of Anagallis in Primulaceae, we compared saponins from species of Myrsinaceae and Primulaceae families and showed that these species were characterized by a pentacyclic triterpenoid saponin with a 13,28-epoxy bridge skeleton. Our phytochemical results increase the knowledge of saponins of the genus Anagallis, their chemotaxonomy and stimulate the evaluation of the biological activities of these saponins.

Chemotaxonomy and Antibacterial Activity of the Extracts and Chemical Constituents of Psychotria succulenta Hiern. (Rubiaceae).

The use of natural products for medicinal purposes is becoming more and more common nowadays, as evidenced by the presence in plants of secondary metabolites with different potentials such as antioxidant and antibacterial properties. We evaluated in this work the antimicrobial activities of the extracts and some isolated compounds from the seeds of Psychotria succulenta Hiern. (Rubiaceae), a Cameroonian medicinal plant traditionally used to cure microbial infections. The ethanol extract was prepared by maceration and extracted with ethyl acetate and n-butanol. The EtOAc (m = 168 g) and n-BuOH (m = 20 g) extracts were further fractionated by silica gel column chromatography to isolation of compounds. Their structures were elucidated by spectroscopic analysis and by comparison with published data. The antibacterial activity of extracts and compounds was assessed by evaluating the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against pathogenic bacteria. Thirteen compounds including four alkaloids (veprisine (1), naucleofficine III (2), vepridimerine B (3), and vepridimerine C (4)), three triterpenes (barbinervic acid (5), 3-O-α-L-rhamnopyranosyl quinovic acid (6), and oleanolic acid (7)), one steroid (ß-sitosterol-3-O-ß-D-glucopyranoside (8)), four phenolic compounds (scopoletin (9), gallic acid (10), quercetin-3-O-ß-D-glucopyranoside (11), and kaempferol 3-O-α-L-rhamnopyranoside-7-O-α-L-rhamnopyranoside (12)), and one iridoid (borreriagenin (13)) were isolated from the EtOAc and n-BuOH extracts. These compounds were identified by 1D and 2D NMR combined analysis as well as by melting point comparison. The EtOH, EtOAc, and n-BuOH extracts exhibited significant antibacterial activities (MIC = 32-128 µg/mL; MBC = 64-256 µg/mL) against Staphylococcus aureus (Gram-positive bacterium), Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumonia (Gram-negative bacteria). Among the isolated compounds, scopoletin (9) showed a moderate activity against Klebsiella pneumoniae with MIC and MBC values of 16 µg/mL and 32 µg/mL, respectively. It appears that, chemotaxonomically, some of the isolated compounds have already been obtained from the genus Psychotria but to the best of our knowledge, this is the first report on the phytochemical investigation of P. succulenta. Although many other studies need to be achieved, our results support the use of P. succulenta in traditional medicine to cure infectious diseases particularly those caused by the tested bacteria.

Anti-Toxoplasma gondii effect of lupane-type triterpenes from the bark of black alder (Alnus glutinosa) and identification of a potential target by reverse docking.

Toxoplasmosis is a worldwide parasitosis that is generally benign. The infestation may pose a risk to immunocompromized patients and to fetuses when pregnant women have recently seroconverted. Current treatments have numerous side effects and chemoresistance is emerging, hence the need to find new anti-Toxoplasma gondii substances. This study focuses on the antiparasitic potential of lupane-type pentacyclic triterpenes isolated from the bark of black alder (Alnus glutinosa), as well as the hypothesis of their macromolecular target by an original method of reverse docking. Among the isolated triterpenes, betulone was the most active compound with an IC50 of 2.7 ± 1.2 µM, a CC50 greater than 80 µM, and a selectivity index of over 29.6. An additional study of the anti-T. gondii potential of commercially available compounds (betulonic acid methyl ester and betulonic acid) showed the important role of the C3 ketone function and the C28 oxidation level on the lupane-type triterpene in the antiparasitic activity since their IC50 and CC50 were similar to that of betulone. Finally, the most active compounds were subjected to the AMIDE reverse docking workflow. A dataset of 87 T. gondii proteins from the Protein Data Bank was created. It identified calcium-dependent protein kinase CDPK3 as the most likely target of betulin derivatives.

TITLE: Potentiel anti-Toxoplasma gondii de triterpènes de type lupane de l'écorce de l'aulne glutineux, Alnus glutinosa, et identification d'une cible potentielle par docking inverse. ABSTRACT: La toxoplasmose est une parasitose mondiale, généralement bénigne. Les personnes à risque sont les patients immunodéprimés et les fœtus chez les femmes enceintes nouvellement séroconverties. Les traitements actuels ont de nombreux effets secondaires et des phénomènes de chimiorésistance apparaissent, d'où la nécessité de trouver de nouvelles substances actives contre T. gondii. Cette étude porte sur le potentiel antiparasitaire des triterpènes pentacycliques de type lupane isolés de l'écorce de l'aulne glutineux (Alnus glutinosa) et formule une hypothèse quant à leur cible protéique par l'utilisation d'une méthode originale de docking inverse. Parmi les triterpènes isolés, la bétulone s'est révélée être la plus active avec une CI50 de 2,7 µM ± 1,2 µM, une CC50 supérieure à 80 µM et un indice de sélectivité supérieur à 29,6. L'étude complémentaire du potentiel anti-T. gondii de composés disponibles commercialement et analogues à la bétulone (acide bétulonique et methyl ester de l'acide bétulonique) a montré le rôle important de la fonction cétone en C3 et du degré d'oxydation de la position 28 du squelette triterpénique de type lupane dans l'activité antiparasitaire puisque leurs CI50 et CC50 étaient similaires aux valeurs rencontrées pour la bétulone. Enfin, les composés les plus actifs ont été soumis au flux de travail de docking inverse d'AMIDE. Un ensemble de 87 protéines de T. gondii de la Protein Data Bank a été créé. La protéine kinase calcium dépendante CDPK3 a été identifiée comme la cible la plus probable des dérivés de la bétuline.

Investigation of Antiparasitic Activity of 10 European Tree Bark Extracts on Toxoplasma gondii and Bioguided Identification of Triterpenes in Alnus glutinosa Barks.

Toxoplasmosis is a worldwide parasitosis that affects one-third of the population. People at risk, such as immunocompromised patients (AIDS, chemotherapy treatment) or fetuses (maternal-fetal transmission) can develop severe forms of the disease. The antiparasitic activity of extracts of different polarities (n-heptane, MeOH, MeOH/H2O) of 10 tree species endemic to temperate regions was investigated against Toxoplasma gondii infection in vitro. Our results showed that the n-heptane extract of the black alder (Alnus glutinosa) exhibited a significant antiparasitic activity without any cytotoxicity at the tested concentrations, with an IC50 of up to 25.08 µg/mL and a selectivity index higher than 3.99. The chemical profiling of this extract revealed triterpenes as major constituents. The ability of commercially available triterpene (betulin, betulinic acid, and betulone) to inhibit the growth of T. gondii was evaluated and showed growth inhibition rates of 44%, 49%, and 99% at 10 µM, respectively.

Antimicrobial and Antioxidant Secondary Metabolites from Trifolium baccarinii Chiov. (Fabaceae) and Their Mechanisms of Antibacterial Action.

The treatment of infectious diseases with antimicrobial agents continues to present problems in modern-day medicine with many studies showing significant increase in the incidence of bacterial resistance to several antibiotics. The screening of antimicrobial activity of plant extracts and natural products has shown that medicinal plants are made up of a potential source of new anti-infective agents. The aim of this study was to evaluate the antimicrobial and antioxidant activities of extracts and compounds from the whole plant Trifolium baccarinii Chiov. and to determine their modes of antibacterial action. The plant extracts were prepared by maceration in organic solvents. The antimicrobial activities were evaluated using the broth microdilution method. The antioxidant activity was evaluated using the 2,2'-diphenyl-1-picrylhydrazyl radical (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) assays. The mechanisms of antibacterial action were determined by lysis, salt tolerance assays, and antioxidant enzyme activities. The cytotoxic effect on the erythrocytes was determined by a spectrophotometric method. Biochanin A, formononetin, luteolin, luteolin-4'-O-ß-D-glucopyranoside, 4,7,2'-trihydroxy-4'-methoxyisoflavanol, sissotrin, 1-methyl-ß-D-glucopyranoside, ononin, D-mannitol, and 3-O-ß-D-glucuronopyranosylsoyasapogenol B were isolated from Trifolium baccarinii. The MeOH, EtOAc, and n-BuOH extracts as well as biochanin A, formononetin, luteolin, luteolin-4'-O-ß-D-glucopyranoside, 4,7,2'-trihydroxy-4'-methoxyisoflavanol, and sissotrin from Trifolium baccarinii displayed the highest antimicrobial and antioxidant activities. The MeOH extract and 4,7,2'-trihydroxy-4'-methoxyisoflavanol exhibited antibacterial activity through the bacteriolytic effect and reduction of the antioxidant defenses in the bacterial cells. The present study portrays Trifolium baccarinii as a potential natural source of antibacterial, antifungal, and antioxidant agents.

AMIDE v2: High-Throughput Screening Based on AutoDock-GPU and Improved Workflow Leading to Better Performance and Reliability.

Molecular docking is widely used in computed drug discovery and biological target identification, but getting fast results can be tedious and often requires supercomputing solutions. AMIDE stands for AutoMated Inverse Docking Engine. It was initially developed in 2014 to perform inverse docking on High Performance Computing. AMIDE version 2 brings substantial speed-up improvement by using AutoDock-GPU and by pulling a total revision of programming workflow, leading to better performances, easier use, bug corrections, parallelization improvements and PC/HPC compatibility. In addition to inverse docking, AMIDE is now an optimized tool capable of high throughput inverse screening. For instance, AMIDE version 2 allows acceleration of the docking up to 12.4 times for 100 runs of AutoDock compared to version 1, without significant changes in docking poses. The reverse docking of a ligand on 87 proteins takes only 23 min on 1 GPU (Graphics Processing Unit), while version 1 required 300 cores to reach the same execution time. Moreover, we have shown an exponential acceleration of the computation time as a function of the number of GPUs used, allowing a significant reduction of the duration of the inverse docking process on large datasets.

Antibacterial, antifungal and antioxidant activities of whole plant chemical constituents of Rumex abyssinicus.

BACKGROUND: Antibiotic resistance has contributed to the burden of infectious diseases both in the hospital and community setting, and represents a great threat to public health. Previous studies have revealed the role of reactive oxygen species as intermediate mediators of tissue damage, following antibiotherapies, indicating the need of associating antioxidants to these treatments. Therefore, the present work was designed to study the antibacterial, antifungal and antioxidant activities of extracts and compounds from Rumex abyssinicus Jacq. (Polygonaceae), as well as to investigate the antibacterial mechanisms of action of the most effective agents. METHODS: The plant extracts were prepared by maceration in organic solvents followed by column chromatography of the EtOAc fraction and purification of different fractions which led to the isolation and characterization of pure compounds. The antimicrobial activities of the extracts/compounds and their combinations with ciprofloxacin and fluconazole were evaluated using the broth microdilution method by determining the minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC). The effects of the extracts on the bacterial cell membrane and microbial respiratory chain dehydrogenase enzyme activity were determined by spectrophotometric methods. Antioxidant activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and gallic acid equivalent antioxidant capacity (GAEAC) assays. RESULTS: Chrysophanol (1), physcion (2), Ergosta-6,22-diene-3,5,8-triol (3), emodin (4), 6-hydroxyemodin (citreorosein) (5), chrysophanein (6) and physcionin (7) were isolated from EtOAc fraction of R. abyssinicus and displayed different degrees of antimicrobial activities (MIC = 8-256 µg/mL). The MeOH extract and compounds 2 and 4 exhibited synergistic effects with ciprofloxacin and fluconazole. Compounds 1, 2 and the combined mixture of 6 + 7 displayed the highest antioxidant activity (GAEAC = 83.38-106.03 µg/mL). CONCLUSION: R. abyssinicus is a potential source of antibacterial, antifungal and antioxidant agents. The antibacterial mechanisms of action of the MeOH extract and compound 2 are due to disruption of the cytoplasmic membrane and inhibition of the microbial respiratory chain dehydrogenase enzyme activity. To the best of our knowledge, this is the first report of test samples and ciprofloxacin / fluconazole association against MDR strains. The observed activity of the isolated compounds against bacteria and fungi including MDR strains deserves further exploration.

Identification and Evaluation of New Potential Inhibitors of Human Neuraminidase 1 Extracted from Olyra latifolia L.: A Preliminary Study.

Sialidases, also called neuraminidases, are involved in several human pathologies such as neurodegenerative disorders, cancers, as well as infectious and cardiovascular diseases. Several studies have shown that neuraminidases, such as neuraminidase 1 (NEU-1), may be promising pharmacological targets. Therefore, the discovery of new selective inhibitors of NEU-1 are necessary to better understand the biological functions of this sialidase. In the present study, we describe the isolation and characterization of nine known compounds from Olyra latifolia L. leaves. This plant, known to have several therapeutic properties, belongs to the family of Poaceae and is found in the neotropics and in tropical Africa and Madagascar. Among the purified compounds, feddeiketone B, 2,3-dihydroxy-1-(4-hydroxy-3,5-diméthoxyphényl)-l-propanone, and syringylglycerol were shown to present structural analogy with DANA, and their effects on membrane NEU-1 sialidase activity were evaluated. Our results show that they possess inhibitory effects against NEU-1-mediated sialidase activity at the plasma membrane. In conclusion, we identified new natural bioactive molecules extracted from Olyra latifolia as inhibitors of human NEU-1 of strong interest to elucidate the biological functions of this sialidase and to target this protein involved in several pathophysiological contexts.

Pyrroloquinolone A, a new alkaloid and other phytochemicals from Atractylis cancellata L. with antioxidant and anticholinesterase activities.

A new alkaloid pyrroloquinolone A (1), along with fifteen known compounds 2-16 were isolated from the petroleum ether, EtOAc and n-BuOH extracts of the whole plant Atractylis cancellata L. Their structures were elucidated on the basis of extensive spectroscopic analysis including 1D- and 2D-NMR and HR-ESI-MS techniques. This is the first report of alkaloids in the genus Atractylis. Some of the isolated compounds and extracts were evaluated for their antioxidant potential (scavenging activity of DPPH and ABTS radicals, and reducing Fe+3 and Cu+2 power assays) and acetylcholinesterase and butyrylcholinesterase inhibitory activities. Compounds 8 and 11 showed good antioxidant capacity compared to ascorbic acid, BHA, and BHT used as standards, whereas compounds 1 and 2 exhibited good anticholinesterase activities compared to galantamine used as standard.

Semipapposides A-M, triterpenoid bidesmosides saponins from the roots of Scabiosa semipapposa.

Phytochemical investigations of the roots of Scabiosa semipapposa Salzem ex D.C. have led to the isolation of 12 undescribed triterpenoid saponins named semipapposides A-L, one undescribed saponin semipapposide M obtained as an inseparable mixture, together with three known oleanolic acid glycosides. Their structures were elucidated by analysis of 1D and 2D-NMR (1H-1H COSY, TOCSY, HSQC-TOCSY, HSQC, ROESY or NOESY, and HMBC) spectroscopic data and mass spectrometry (HR-ESI-MS), and by comparison with those of related metabolites. All saponins possess a partial sequence rhamnopyranosyl-(1 â†’ 2)-xylopyranosyl or rhamnopyranosyl-(1 â†’ 2)-arabinopyranosyl- at C-3 of the aglycon and a gentiobiose unit at C-28. These results represent a contribution to the knowledge of the saponins of Scabiosa species and their chemotaxonomy.

In Vitro and In Vivo Activity of Anogeissus leiocarpa Bark Extract and Isolated Metabolites against Toxoplasma gondii.

Toxoplasma gondii, belonging to the Apicomplexa phylum, is a cosmopolitan protozoan parasite that affects at least 30% of the world's population. In West Africa, the leaves and bark of the tree species Anogeissus leiocarpa (DC.) Guill. & Perr. are used against zoonosis in traditional medicine and play a key role in controlling diseases induced by Apicomplexans such as malaria. In this study, extracts, fractions, and pure compounds obtained from an ethanol extract of the bark of A. leiocarpa were evaluated against T. gondii infection in vitro and in vivo. The crude bark extract showed significant activity on tachyzoites from the T. gondii RH strain (IC50 = 59.30 µg/mL). The crude bark extract without tannins and pure trachelosperogenin E purified by centrifugal partition chromatography showed the highest activity (IC50s = 12.83 and 26.63 µg/mL, respectively) with satisfying selectivity indexes of 9.61 and 9.75, respectively. The crude bark extract without tannins and pure trachelosperogenin E were able to significantly inhibit host cell invasion by the parasite in vitro, while the crude bark extract without tannins was able to increase mice survival in our murine model of chronic toxoplasmosis. These results provide new biological data for natural compounds that could enhance the current panoply of treatments against toxoplasmosis.

Triterpene saponins from Silene gallica collected in North-Eastern Algeria.

Eleven previously undescribed triterpene saponins, named silenegallisaponin A-K (1-11), were isolated from the aerial parts of Silene gallica L. Their structures were elucidated by analysis of 1D and 2D-NMR spectroscopic data and mass spectrometry (HR-ESI-MS). The saponins comprised caulophyllogenin, echinocystic acid, or quillaic acid substituted at C-3 by a ß-d-glucuronic acid or ß-d-galactopyranosyl-(1 â†’ 3)-ß-d-glucuronopyranoside and at C-28 by a ß-d-fucopyranose substituted at C-2 by a ß-d-glucose and at C-3 by a ß-d-glucose or a ß-d-quinovose.