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The bioassay-guided fractionation of the n-hexane extract of Citrus reticulata Blanco (Rutaceae) stem bark yielded scoparone (1), xanthyletin (2), lupeol (3), β-amyrin (4), stigmasterol (5), β-sitosterol (6) and palmitic acid. The structures of these compounds were determined by comprehensive spectroscopic analyses, i.e., 1D and 2D NMR and EI-MS, and by comparison with the reported data. Extracts, fractions and isolated compounds 1-6 were assessed for cytotoxicity by the 3-(4,5-dimethylthiazol-2-yl)-2,5-dphenyltetrazolium bromide (MTT) assay against three human cancer cell lines, i.e., human lung adenocarcinoma cell line A549, human breast adenocarcinoma cell line MCF7 and human Caucasian prostate adenocarcinoma cell line PC3. Significant activity of the n-hexane and the dichloromethane extracts was observed against the breast cancer cell line MCF7 with IC 50 s of 45.6 and 54.7 μg/mL, respectively. Moreover, the 70% ethyl acetate in n-hexane chromatographic fraction showed significant activity displaying IC 50 values of 53.0, 52.4 and 49.1 μg/mL against the cancer cell lines A549, MCF7 and PC3, respectively. Encouragingly, an IC 50 of 510.0 μg/mL against the human normal prostate cell line PNT2 indicated very low toxicity and hence favourable selectivity indices for the 70% ethyl acetate in n-hexane fraction in the range of 9.6-10.4 towards cell lines A549, MCF7 and PC3. Because compounds isolated from the above fraction only delivered IC 50 values in the range of 18.2-96.3, 9.2-34.1 and 7.5-97.2 μg/mL against A549, MCF7 and PC3 cell lines, respectively, synergistic action between compounds is suggested. Bioassay results valorize the anticancer effectivity of the stem bark of this plant in Cameroonian pharmacopoeia. Copyright © 2017 John Wiley & Sons, Ltd., (Copyright © 2017 John Wiley & Sons, Ltd.)

Aims: Traditional medicinal use of species of the genus Drypetes is widespread in the tropical regions. The aim of this review is to systematically appraise the literature available to date on phytochemistry, ethnopharmacology, toxicology and bioactivity (in vitro and in vivo) of crude extracts and purified compounds., Ethnopharmacological Relevance: Plants of the genus Drypetes (Putranjivaceae) are used in the Subsaharan African and Asian traditional medicines to treat a multitude of disorders, like dysentery, gonorrhoea, malaria, rheumatism, sinusitis, tumours, as well as for the treatment of wounds, headache, urethral problems, fever in young children, typhoid and several other ailments. Some Drypetes species are used to protect food against pests, as an aphrodisiac, a stimulant/depressant, a rodenticide and a fish poison, against insect bites, to induce conception and for general healing. This review deals with updated information on the ethnobotany, phytochemistry, and biological activities of ethnomedicinally important Drypetes species, in order to provide an input for the future research opportunities., Methods: An extensive review of the literature available in various recognized databases e.g., Google Scholar, PubMed, Science Direct, SciFinder, Web of Science, www.theplantlist.org and www.gbif.org, as well as the Herbier National du Cameroun (Yaoundé) and Botanic Gardens of Limbe databases on the uses and bioactivity of various species of the Drypetes was undertaken., Results: The literature provided information on ethnopharmacological uses of the Subsaharan African and Asian species of the genus Drypetes, e.g., Drypetes aubrévillii, D. capillipes, D. chevalieri, D. gerrardii, D. gossweileri, D. ivorensis, D. klainei, D. natalensis, D. pellegrini (all endemic to Africa) and D. roxburghii (Asian species), for the treatment of multiple disorders. From a total of 19 species, more than 140 compounds including diterpenes, sesquiterpenes, triterpenes (friedelane, oleanane, lupane and hopane-type), flavonoids, lignans, phenylpropanoids and steroids, as well as some thiocyanates, were isolated. Several crude extracts of these plants, and isolated compounds displayed significant analgesic, anthelmintic, antidiabetic, anti-emetic anti-inflammatory, antioxidant, antiparasitic, central nervous system depressant, cytotoxic, and insecticidal activities both in vitro and in vivo. Some toxicities associated with the stem, bark, seed and leaf extracts of D. roxburghii, and the flavonoid, amentoflavone, isolated from the stem extract of D. littoralis as well as D. gerrardii, were confirmed in the animal models and in the rat skeletal myoblast cells assays. As a consequence, traditional medicine from this genus should in future be applied with care., Conclusions: Plants of this genus have offered bioactive samples, both from crude extracts and pure compounds, partly validating their effectivity in traditional medicine. However, most of the available scientific literatures lacks information on relevant doses, duration of the treatment, storage conditions and positive controls for examining bioefficacy of extract and its active compounds. Additional toxicological studies on the species used in local pharmacopeia are urgently needed to guarantee safe application due to high toxicity of some crude extracts. Interestingly, this review also reports 10 pimarane dinorditerpenoids structures with the aromatic ring C, isolated from the species collected in Asia Drypetes littoralis (Taiwan), D. perreticulata (China), and in Africa D. gerrardii (Kenya), D. gossweileri (Cameroon). These compounds might turn out to be good candidates for chemotaxonomic markers of the genus., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Reversed-phase preparative high-performance liquid chromatography (HPLC) of the methanol extract of the aerial parts of Euphorbia petiolata Banks & Soland, an endemic Iranian medicinal plant, yielded ten free radical scavengers including eight flavonoid glycosides myricetin 3-O-glucoside (1), kaempferol 3-O-(2-O-galloyl)-glucoside (2), myricetin 3-O-rhamnoside (3), quercetin 3-O-glucoside (4), kaempferol 3-O-glucoside (5), quercetin 3-O-rhamnoside (6), kaempferol 3-O-rhamnoside (7), and quercetin 3-O-rutinoside (10), a coumarin esculetin (8) and a phenylpropanoid 2-hydroxydihydrocinnamic acid (9). The structures of these compounds were elucidated conclusively by spectroscopic means and also by direct comparison of their spectroscopic data with respective published data. The free radical scavenging properties of these compounds were assessed by the 2,2-diphenyl-1-picrylhydrazyl assay.

Seven free-radical-scavenging phenolic compounds including five flavonoids, rutin (1), chrysoeriol 7-O-rutinoside (2), kaempferol 3-O-glucoside (3), chrysoeriol 7-O-glucoside (4) and naringenin (5), and two phenylethanoid glycosides, forsythoside B (6) and acteoside (7) were isolated from the methanol extract of the aerial parts of the Iranian medicinal plant Phlomis caucasica by reversed-phase preparative high-performance liquid chromatography (HPLC), and the structures of these compounds were elucidated by spectroscopic means. The free-radical-scavenging properties of 1-7 were assessed by 2,2-diphenyl-1-picryl hydrazyl (DPPH) assay. Among these compounds, forsythoside B (6) and acteoside (7) were found to be the most potent antioxidants with the RC(50) values of 4.97 and 4.27 microg/ml, respectively.

Based on ethnopharmacological and taxonomic information, seeds of 21 Scottish plant species from 14 different families were obtained from authentic seed suppliers. Their n-hexane, dichloromethane and methanol extracts were assessed for antibacterial activity against 11 pathogenic bacterial species. Methanol extracts of 11 plant species showed significant antibacterial activity. Malva moschata and Prunus padus were active against five bacterial species, Reseda lutea against four, Centaurium erythraea and Crithmum maritimum against three, Calluna vulgaris against two, and Armeria maritima, Centaurea scabiosa, Daucus carota, Rosa canina and Stellaria holostea against one bacterial species. C. erythraea and P. padus were also active against methicillin resistant Staphylococcus aureus.