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Phytochemical investigation of the methanol extracts from the leaves and bark of Senna siamea resulted in the isolation of one new flavone C-glycoside: apigenin-8-C-[6''-(E)-feruloyl]-β-D-glucopyranoside] (1), together with sixteen known compounds including quercetin-3-O-α-L-rhamnoside (2), vitexin (3), isovitexin (4), quercetin-3-O-β-D-glucopyranoside (5), quercetin-3-O-β-D-arabinopyranoside (6), quercetin (7), kaempferol (8), methyl inositol (9), sucrose (10), betulinic acid (11), vanillic acid (12), stigmastane-3β,6α-diol (13), aurantiamide acetate (14), robinetinidol (15), catechin (16) and epicatechin (17). The structures of these compounds were established on the basis of their spectroscopic (1 D and 2 D NMR) and mass spectrometric (ESI-TOF-MS) data. The methanol extracts, fractions and some of the isolated compounds were screened for their antimicrobial properties against five microbial strains. The methanol extract and the ethyl acetate fraction from the bark showed very weak antifungal activity against C. glabrata with the same MIC value of 128 μg/mL. Compound 7 was weakly active against C. albicans with MIC of 32 μg/mL. [ABSTRACT FROM AUTHOR]

Prenylated flavonoids are a special kind of flavonoid derivative possessing one or more prenyl groups in the parent nucleus of the flavonoid. The presence of the prenyl side chain enriched the structural diversity of flavonoids and increased their bioactivity and bioavailability. Prenylated flavonoids show a wide range of biological activities, such as anti-cancer, anti-inflammatory, neuroprotective, anti-diabetic, anti-obesity, cardioprotective effects, and anti-osteoclastogenic activities. In recent years, many compounds with significant activity have been discovered with the continuous excavation of the medicinal value of prenylated flavonoids, and have attracted the extensive attention of pharmacologists. This review summarizes recent progress on research into natural active prenylated flavonoids to promote new discoveries of their medicinal value. [ABSTRACT FROM AUTHOR]

In this study, phytochemical investigation on the chloroform soluble fraction of seed kernels of Caesalpinia bonduc led to the isolation of two new cassane-type diterpenoids, norcaesalpinin Q (1) and caesalpinin MR (2), together with seven known compounds (3–9). The structures of the new compounds were elucidated on the basis of extensive NMR spectroscopic and mass spectrometric analyses, and their absolute configurations were determined by electronic circular dichroism (ECD) calculations. All compounds were evaluated for inhibitory effects against NO production of RAW264.7 cells induced by LPS, and compounds 5, 7 and 8 could inhibited the production of NO at the concentration of 50 µM. [ABSTRACT FROM AUTHOR]

Ripe figs, barks, and wood of Ficus vallis-choudae are used in traditional medicine against several conditions including nausea and malaria. However, its use is still to be scientifically documented and validated. Hence, the aim of the present work was to evaluate the antiplasmodial activity of the dichloromethane-methanol (DCM-MeOH (1:1)) crude extract, their hexane, dichloromethane, ethyl acetate, and methanoli fractions, as well as the isolated chemical constituents. The chemical study of the DCM-MeOH (1:1) crude extract of F. vallis-choudae figs led to the isolation of fifteen (15) known compounds identified based on their spectroscopic data [one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR), mass spectrometry] and by comparison of these data with those reported in the literature. Some of the isolated compounds were assessed in vitro for their antiplasmodial activity against Plasmodium falciparum chloroquine-sensitive 3D7 (Pf3D7) and multidrug-resistant Dd2 strains. The dichloromethane fraction exhibited very good antiplasmodial activity against both strains with IC50 values of 13.86 μg/mL and 8.18 μg/mL, respectively. Among the tested compounds, wighteone (2) was the most active against P. falciparum 3D7 (IC50 = 24.6 ± 1.5 μM) and Dd2 (IC50 = 11.9 ± 2.4 μM) strains. The obtained results could justify the traditional uses of F. vallis-choudae against malaria. Wighteone appears to be the most active ingredient. However, further consideration of this compound as starting point for antimalarial drug discovery will depend upon its selectivity of action towards Plasmodium parasites. Highlights: • 15 (fifteen) compounds were isolated from the dichloromethane-methanol extract of Ficus vallis-choudae. • Their structures were determined on the basis of their spectroscopic data. • The dichloromethane fraction showed promising activities on the Pf3D7 and PfDd2 strains with IC50 values of 13.86 and 8.18 µg/mL, respectively. • Wighteone was the most active compound against PfDd2 (IC50 = 11.9 ± 2.4 μM). [ABSTRACT FROM AUTHOR]

A new isoflavone (Z)-5,7,4′-trihydroxy-3′-[3-hydroxy-3-methyl-1-butenyl] isoflavone (1) together with seven known isoflavones (2–8) were isolated from the fruits of the Ficus auriculata. Their structures were established on the basis of 1 D, 2 D-NMR spectroscopic data and HR-ESI-MS analysis. All compounds were evaluated for their antibacterial activities against five pathogenic bacteria in vitro. Compounds 3 and 4 exhibited significant antibacterial activities against five pathogenic bacteria with the MIC values ranging from 1.25 to 20 μg/mL. [ABSTRACT FROM AUTHOR]

The phytochemical investigation of the methanol extract of the stem bark of Gilbertiodendron dewevrei led to the isolation of two new secondary metabolites, 5,7-dihydroxy-4′-methoxyisoflavan-2,4-dione (1) and 23-hydroxy-2-tricosanone (2) along with 19 known compounds (3–21). The structure of these compounds were established by interpretation of their spectral data, mainly HR-TOFESIMS, 1 D NMR (1H, 13C and DEPT) and 2 D NMR (1H–1H COSY, HSQC, HMBC, and NOESY), and by comparison with those reported in the literature. The methanol extract and some isolates were screened for their antiradical, antibacterial, and inhibitory properties against acetylcholinesterase. [ABSTRACT FROM AUTHOR]

Methanolic extracts of liana of Caesalpinia welwitschiana and leaves of C. bonduc were found to possess moderate antifeedant and ovicidal activities against Tuta absoluta. Bioassay-guided isolation of constituents from the most active fraction of C. welwitschiana led to the identification of four known compounds [isobonducellin 1a and bonducellin 1 b, intricatinol 2, (-)-epigallocatechin-3-O-gallate 4] and one new constituent [welwitschianic acid 3]. The most active fraction of C. bonduc afforded two known constituents neocaesalpin L 5 and neocaesalpin A 6. The isolated structures were elucidated on the basis of their MS, UV, IR and 1 & 2 D NMR spectra and by comparison with literature data. Compounds 2, 4-6 were showed antifeedant and ovicidal properties against T. absoluta, some comparable to that of azadirachtin at 50, 100 and 200 ng/µl. Overall, the present study, conclude that the two species of the plant could be a promising source of eco-friendly botanical constituents. [ABSTRACT FROM AUTHOR]

Background: African Traditional Medicine (ATM) is used for the healthcare of about 80% of the rural populations of the continent of Africa. The practices of ATM make use of plant-products, which are known to contain plant-based secondary metabolites or natural products (NPs), likely to play key roles in drug discovery, particularly as lead compounds. For various reasons, including resistance of strains of Plasmodium to known anti-malarial drugs, local African populations often resort to plant-based treatments and/or a combination of this and standard anti-malarial regimens. Emphasis has been laid in this review to present the anti-malarial virtue of the most recently published phytochemicals or natural products, which have been tested by in vitro and in vivo assays. Methods: The data was based on the current version of the African Compound Libraries, which are constantly being updated based on inputs from journal articles and student theses (M.Sc/Ph.D) from African University libraries. Emphasis was laid on data published after 2012. In order to carry out the original data collection, currently being included in the African Compounds Database, individual journal websites were queried using the country names in Africa as search terms. Over 40,000 articles "hits" were originally retrieved, then reduced to about 9000 articles. The retained articles/theses was further queried with the search terms "malaria", "malarial", "plasmodium", "plasmodial" and a combination of them, resulting in over 500 articles. Those including compounds with anti-malarial activities for which the measured activities fell within the established cut off values numbered 55, which were all cited in the review as relevant references. Results and discussion: Pure compounds derived from African medicinal plants with demonstrated anti-malarial/antiplasmodial properties with activities ranging from "very active" to "weakly active" have been discussed. The majority of the 187 natural products were terpenoids (30%), followed by flavonoids (22%), alkaloids (19%) and quinones (15%), with each of the other compound classes being less than 5% of the entire compound collection. It was also observed that most of the plant species from which the compounds were identified were of the families Rubiaceae, Meliaceae and Asphodelaceae. The review is intended to continue laying the groundwork for an African-based anti-malarial drug discovery project. [ABSTRACT FROM AUTHOR]

Drypetes euryodes (Hiern) Hutch., Drypetes gossweileri S. Moore, Drypetes laciniata Hutch. (Putranjivaceae), Rinorea subintegrifolia O. Ktze, and Rinorea woermanniana (Büttner) Engl. (Violaceae) from Gabon were probed for the presence of glucosinolates (GLs). When present, the GLs were identified and quantified by HPLC analysis. 2-Hydroxy-2-methyl GL (1) was the major GL in the cork of D. euryodes. Moreover, 4-hydroxybenzyl GL (2) was the major GL in the seed of D. gossweileri whereas the bark contained 2 as the minor GL and benzyl GL (3) was the major one. In addition, 4-methoxybenzyl GL (4), 3-methoxybenzyl GL (5), and 3 were found in the root of R. subintegrifolia. However, no GL was detected in D. laciniata (leaf and stem), D. euryodes (leaf and stem), and R. woermanniana (leaf and stem-branch). Our results support the hypothesis of the existence of GLs in plants of the Putranjivaceae and Violaceae families (order Malpighiales). [ABSTRACT FROM AUTHOR]

Background: In the Cameroonian traditional medicine, plants of the Capparidaceae, Euphorbiaceae and Liliaceae families are used to treat several metabolic diseases. These plants are rich in various compounds belonging to the glucosinolates and thiosulfinates family. Till date, very little studies have been done aiming at assessing the antioxidant and inflammatory properties of the essential oils (EOs) of these plants. Essential oils are volatile extracts produced by secondary metabolism. They are usually constituted of terpens and may also contain specific non terpenic components such as glucosinolates and thiosulfinates for the species that are being considered in the present study. This study highlights and compares the chemical composition, antioxidant and anti-inflammatory properties of the essential oils of the stem barks of Drypetes gossweileri (Euphorbiaceae), roots of Pentadiplandra brazzeana (Capparidaceae), red bulbs of Allium cepa and Alium sativum (Liliaceae) collected in Cameroon (Central Africa). Methods: The essential oils were extracted by hydrodistillation and analyzed by gas chromatography (GC) and gas chromatography coupled to mass spectrometry (GC-MS). In vitro antioxidant activities were determined using the radical scavenging assay, total phenolic content, ferric reducing antioxidant power (FRAP) assay and determination of antioxidant activity index (AAI) according to the method described by Scherer and Godoy. The anti-inflammatory activities were evaluated using albumin denaturation method. Differences (p < 0.05) between the experimental and the control groups were evaluated using one way analysis of variance (ANOVA) followed by Tukey's test for multiple comparisons. Results: The main components of Allium sativum essential oil were diallyl trisulfide (41.62 %), diallyl disulfide (19.74 %), allyl methyl trisulfide (12.95 %), diallyl sulfide (7.1 %) and diallyl tetrasulfide (4.22 %). Those of Allium cepa essential oil were diallyl trisulfide (22.17 %), dipropyl trisulfide (11.11 %), 2-methyl-3,4-dithiaheptane (9.88 %), methyl propyl trisulfide (8.14 %), dipropyl tetrasulfide (8.07 %) and 2-propenyl propyl disulfide (5.15 %). Drypetes gossweileri and Pentadiplandra brazzeana essential oils presented similar chemical compositions as compared with benzylisothiocyanate content (63.19 and 97.63 % respectively), but differed in benzylcyanide content (35.72 and 0.86 % respectively). The essential oils were rich in phenolic compounds in the following order Allium sativum < Allium cepa < D. gossweileiri < P. brazzeana. The essential oils exhibited high antioxidant and DPPH radical scavenging effect but low ferric reducing power activity. Moreover, the four essential oils showed anti-inflammatory activities (by heat denaturation of Bovine Serum Albumin). The anti-inflammatory activities of P. brazzeana and A. cepa essential oils were comparable but higher than those of D. gossweileri and sodium diclofenac used as a reference non-steroidal anti-inflammatory drug. Conclusion: The essential oils of the plants were rich in organosulfur compounds. These compounds were probably responsible for their appreciable antioxidant and anti-inflammatory activities. Due to their antioxidant and anti-inflammatory properties, the essential oils of some of these plants might be used as natural additives in the pharmaceutical, cosmetic and agro-industries. [ABSTRACT FROM AUTHOR]

Malaria is currently a public health concern in many countries in the world due to various factors which are not yet under check. Drug discovery projects targeting malaria often resort to natural sources in the search for lead compounds. A survey of the literature has led to a summary of the major findings regarding plant-derived compounds from African flora, which have shown anti-malarial/antiplasmodial activities, tested by in vitro and in vivo assays. Considerations have been given to compounds with activities ranging from "very active" to "weakly active", leading to >500 chemical structures, mainly alkaloids, terpenoids, flavonoids, coumarins, phenolics, polyacetylates, xanthones, quinones, steroids and lignans. However, only the compounds that showed anti-malarial activity, from "very active" to "moderately active", are discussed in this review. [ABSTRACT FROM AUTHOR]

Background: In Cameroon herbs are traditionally used to meet health care needs and plans are on the way to integrate traditional medicine in the health care system, even though the plans have not been put into action yet. The country however has a rich biodiversity, with ~8,620 plant species, some of which are commonly used in the treatment of several microbial infections and a range of diseases (malaria, trypanosomiasis, leishmaniasis, diabetes and tuberculosis). Methods: Our survey consisted in collecting published data from the literature sources, mainly from PhD theses in Cameroonian university libraries and also using the author queries in major natural product and medicinal chemistry journals. The collected data includes plant sources, uses of plant material in traditional medicine, plant families, region of collection of plant material, isolated metabolites and type (e.g. flavonoid, terpenoid, etc.), measured biological activities of isolated compounds, and any comments on significance of isolated metabolites on the chemotaxonomic classification of the plant species. This data was compiled on a excel sheet and analysed. Results: In this study, a literature survey led to the collection of data on 2,700 secondary metabolites, which have been previously isolated or derived from Cameroonian medicinal plants. This represents distinct phytochemicals derived from 312 plant species belonging to 67 plant families. The plant species are investigated in terms of chemical composition with respect to the various plant families. A correlation between the known biological activities of isolated compounds and the ethnobotanical uses of the plants is also attempted. Insight into future direction for natural product search within the Cameroonian forest and Savanna is provided. Conclusions: It can be verified that a phytochemical search of active secondary metabolites, which is inspired by knowledge from the ethnobotanical uses of medicinal plants could be very vital in a drug discovery program from plant-derived bioactive compounds. [ABSTRACT FROM AUTHOR]

Background: Malaria remains a significant public health challenge in regions of the world where it is endemic. An unprecedented decline in malaria incidences was recorded during the last decade due to the availability of effective control interventions, such as the deployment of artemisinin-based combination therapy and insecticide-treated nets. However, according to the World Health Organization, malaria is staging a comeback, in part due to the development of drug resistance. Therefore, there is an urgent need to discover new anti-malarial drugs. This article reviews the literature on natural products with antiplasmodial activity that was reported between 2010 and 2017. Methods: Relevant literature was sourced by searching the major scientific databases, including Web of Science, ScienceDirect, Scopus, SciFinder, Pubmed, and Google Scholar, using appropriate keyword combinations. Results and Discussion: A total of 1524 compounds from 397 relevant references, assayed against at least one strain of Plasmodium, were reported in the period under review. Out of these, 39% were described as new natural products, and 29% of the compounds had IC50 ≤ 3.0 µM against at least one strain of Plasmodium. Several of these compounds have the potential to be developed into viable anti-malarial drugs. Also, some of these compounds could play a role in malaria eradication by targeting gametocytes. However, the research into natural products with potential for blocking the transmission of malaria is still in its infancy stage and needs to be vigorously pursued. [ABSTRACT FROM AUTHOR]

Background: The Atlantic Forest biome extends along the entire Brazilian coast and is home to approximately 20,000 plant species, many of which are endemic; it is considered one of the hotspot regions of the planet. Several of these species are sources of natural products with biological activities that are still unknown. In this study, we evaluated the antimicrobial activity of 90 extracts derived from native Atlantic Forest tree species against Staphylococcus aureus, an important human and veterinary pathogen. Methods: Extracts from native Atlantic Forest tree species were evaluated for their antimicrobial activity against S. aureus by in vitro standard methods. Phytochemical fractionation of the extract from Maclura tinctoria was performed by liquid-liquid partitioning. LC-DAD-ESI-MS was used for identification of constituents in the most active fraction. Damage of cells and alterations in the permeability of cell membrane were determined by atomic force microscopy (AFM) and crystal violet uptake assay, respectively. In vivo antimicrobial activity was evaluated using Galleria mellonella larvae infected with S. aureus with survival data collected using the Kaplan-Meier method. Results: Among the organic or aqueous extracts tested here, 26 showed biological activity. Eight species showed relevant results, with a minimum inhibitory concentration (MIC) below 1 mg/mL. Antibacterial activity was registered for three species for the first time. An organic extract from Maclura tinctoria leaves showed the lowest MIC (0.08 mg/mL). Fractionation of this extract by liquid-liquid partitioning led to obtaining fraction 11FO d with a MIC of 0.04 mg/mL. This fraction showed strong activity against veterinary S. aureus isolates and contributed to the increased survival of Galleria mellonella larvae infected with S. aureus ATCC 29213. The bacterial surface was not altered by the presence of 11FO d, and no cell membrane damage was detected. The LC-DAD-ESI/MS analyses identified prenylated flavonoids as the major constituents responsible for the antibacterial activity of this active extract. Conclusion: A fraction enriched in prenylated isoflavones and flavanones from M. tinctoria showed in vitro and in vivo efficacy as antistaphylococcal agents. These findings justify the need for further research to elucidate the mechanisms of action of these compounds. [ABSTRACT FROM AUTHOR]