Chemical investigation of the ethyl acetate extract of the fungal strain DH-SO21-2012, which was isolated from healthy leaf tissues of the Moroccan medicinal plant Salvia officinalis, yielded a new secondary metabolite 2 together with its known congener 1 as well as the known compound 3. The structures of all compoundswere determined on the basis of 1D and 2D NMR analyses as well as mass spectrometry. The isolated compounds were subjected to various bioassays to examine their ability to inhibit the chaperone Hsp90 machinery, antimicrobial and cytotoxic activities.

We report in this study the chemical composition and antibacterial activities of the seed’s essential oils of Pimpinella anisum L. collected from Morocco and Yemen. The hydro-distillation technique was used to extract their essential oils, followed by continuous liquid-liquid fractionation using water and ethyl acetate as solvent system. Obtained essential oils were analyzed by gas chromatography (GC) and gas chromatography-mass spectroscopy (GC-MS). GC and GC/MS results showed that 4-allylanisole was the major compound of Pimpinella anisum L. with percentages of 76.70 and 85.28% of Moroccan and Yemen, respectively, in addition to other minor compounds such as limonene (9.75% for Moroccan species and 5.53% for Yemen species) and fenchone (6.16% for Moroccan species and 4.12% for Yemen species). Furthermore, both essential oils were evaluated for their antibacterial activity against a panel of pathogenic microorganisms. The results showed that both essential oils inhibit most pathogenic bacteria tested.

Trypanosomiasis is one of the public health problems, especially in tropical and subtropical regions and has been categorised by WHO as one of the neglected diseases. Therefore the search for novel, effective and safer drugs for the treatment of this disease continues 1. A number of studies revealed that many plants are potential sources of novel trypanocidal compounds2. We carried out in vitro and in vivo studies to determine the antitrypanosomal effects of the methanol extract of Vitex simplicifolia using Trypanosoma brucei brucei infected mice and Trypanosoma brucei rhodesiense. Successive extractions with hexane, dichloromethane (DCM), ethyl acetate, n-butanol and water coupled with activity guided fractionation proved the bioactivity of the DCM fraction. Further analysis of the DCM fraction by vacuum liquid chromatography, gel filtration using sephadex LH20, monitored with HPLC was followed by semi preparative HPLC to yield six pure compounds including 3,5,7-trihydroxy-2-(4-hydroxyphenyl)-4 H-chromen-4-one (1), 3,5,7,8-tetrahydroxy-2-(4-methoxyphenyl) chroman-4-one (2), 5,7-dihydroxy-2-(4-hydroxy-3-methoxyphenyl)-3-methoxy-4 H-chromen-4-one (3), 5-hydroxy-2-(4-hydroxyphenyl)-3,6,7-trimethoxy-4 H-chromen-4-one (4), 5-hydroxy– 2-(4-hydroxyphenyl)-3,7-dimethyoxy-4 H-chromen-4-one (5) and 2-(3,4-dimethoxyphenyl)-7-hydroxy-4 H-chromen-4-one (6). The structures of the isolated compounds were elucidated by 1- and 2D NMR spectroscopy, mass spectrometry as well as comparison with literature data. Compounds 4 – 6 exhibited significant trypanocidal activities ranging from 6.43 to 12.3 µg/ml and the cytotoxicity ranges from 1.58 to 6.64 µg/ml. This is the first report of trypanocidal effect of flavonoids from this plant.

Chemical investigation of the methanol leaf extract of Maytenus senegalensis led to the isolation of 16 compounds, including the new maysecyclononeone A, (6S, 9S) 9,10-dihydroxy-4,7Z-megastigmadien-3-one, mayselignoside A and maysefuropyranone A. In addition the following known compounds, viz. (+) lyoniresinol, (-) isolariciresinol, dihydrodehydrodiconiferyl alcohol, (-) epicathechin, (+) gallocatechin, (-) epigallocatechin, procyanidin B-2, 2,3-Dihydrokaempferol 3-O-β-D-glucopyranoside, quercetin 3-O-β-D-glucopyranoside, kaempferol 3-O-β-D- xylopyranoside, 3,5-dimethylgallate and benzoyl maleic acid were also isolated. The structures of the compounds were deduced by a combination of 1 D and 2 D NMR spectroscopy and high resolution mass spectrometry. All compounds were tested for cytotoxicity against mouse lymphoma cell line (L5178Y). Of the 16 compounds only (-) epigallocatechin showed high cytotoxicity and completely inhibited cell growth at the dose of 10 µg/mL.

The potential of endophytic fungi as promising sources of bioactive natural products continues to attract broad attention. Endophytic fungi are defined as fungi that live asymptomatically within the tissues of higher plants. This overview will highlight the uniqueness of endophytic fungi as alternative sources of pharmaceutically valuable compounds originally isolated from higher plants, e.g. paclitaxel, camptothecin and podophyllotoxin. In addition, it will shed light on the fungal biosynthesis of plant associated metabolites as well as new approaches developed to improve the production of commercially important plant derived compounds with the involvement of endophytic fungi.

The focus of drug discovery is currently shifting more in favour of plant derived microorganisms such as endophytic fungi [1 – 2], which have been found ubiquitous in their host plants. Nigerian medicinal plants, which hitherto have been poorly investigated, could hold enormous potentials as sources of novel fungi endophytes of medicinal importance. Our investigation of 10 medicinal plant species collected from the rainforest zone in Nigeria led to the isolation of 40 pure strains of fungi endophytes. The crude metabolites of these fungi endophytes were screened for cytotoxic activity against mouse lymphoma cell line (L5178Y) and for antimicrobial activity against strains of Gram positive and Gram negative bacteria as well as on some fungal strains. Further chemical investigation of two of the most promising fungi strains Corynespora cassiicola isolated from Gongronema latifolium leaves and Xylaria spp isolated from Psidium guajava leaves yielded 19 biomolecules. These included the new corynesidone D, corynether B and corynether lactone A from Corynespora cassiicola and the new (E) -methyl 3-(4-(3-oxocyclobutyl)phenyl) acrylate, 5,6-dihydro-7-oxo-19, 20- α-epoxycytochalasin C, 18-desoxy-19, 20- α-epoxycytochalasin C and 18-desoxycytochalasin C from Xylaria spp. These compounds are currently being investigated for their cytotoxicity against some selected human cancer cell lines and their ability to modulate the chaperoning activity of the Hsp90 chaperoning machine in vitro. To the best of our knowledge, this is the first report on the isolation of endophytes from these plant species and the results so far are quite fascinating.

Chemical investigation of the endophytic fungal strain Talaromyces wortmannii, isolated from the medicinal plant Aloe vera (Xanthorrhoeaceae), yielded three atropodiastereomeric pairs, including two symmetrical bisdihydroanthracenones, flavomannin A and its new atropisomer flavomannin B, two new asymmetrical bisdihydroanthracenones, and two new dihydroanthracenone/anthraquinone dimers. The planar structures of the new derivatives were unequivocally identified by spectroscopic and mass spectrometric analyses. The axial chirality of the biaryls was deduced from TDDFT ECD and VCD calculations, which however failed to establish the central chirality elements of flavomannin A. All six compounds exhibited antibacterial activity, predominately directed against Staphylococcus aureus, including even high-level (multi)drug-resistant isolates, with MIC values from 4 to 8 µg/mL for the most active compounds. Further Gram-positive genera (Streptococcus, Enterococcus, Bacillus) were moderately affected (MIC 32 to 64 µg/mL). Reporter gene analyses in Bacillus subtilis indicated induction of SOS response for some derivatives, suggesting interference with DNA structure or metabolism. Accordingly, fluorescence microscopy demonstrated defective segregation of the bacterial chromosome and DNA degradation (J. Med. Chem. 2013, 56(8):3257 – 72). The compounds showed no activity when tested against eukaryotic THP-1 cells (leukemia cell line) and BALB cells (mouse embryonic fibroblasts) (> 32 µg/mL).

Fungi are very known to produce polyketides, which are structurally a very diverse family of natural products with interesting biological activities and pharmacological properties. We report in this study the chemical investigation of two endophytic fungi, Stemphylium globuliferum and Talaromyces wortmanii. Several rare new atropisomers were isolated and identified, including homo- and heterodimeric bisanthraquinones. The structure of isolated compounds were determined on the basis of one- and two-dimensional NMR spectroscopy and mass spectrometry. The absolute stereochemistry of the new compounds was established by means of TDDFT ECD calculations. Furthermore, the isolated compounds exhibited antibacterial activity against multi drug resistant strains of Staphylococcus aureus, Streptococcus pneumoniae, Enterococcus faecium and Enterococcus cloacae. In addition, the anti-fungal activity of the isolated compounds was measured against drug resistant strains of Aspergillus fumigatus, Aspergillus faecalis, Candida albicans and Candida krusei. Interestingly, among the compounds isolated, only the new altersolanol N, tetrahydroaltersolanol B and altersolanol C were active against HV2 and HV8 human viruses.

During our ongoing search for new bioactive metabolites from endophytic fungi with focus on the discovery of new antimicrobial compounds, we investigated the fungal strain Stemphylium globuliferum isolated from the medicinal plant Mentha pulegium (Lamiaceae). The EtOAc extract of the poorly investigated S. globuliferum fungal strain afforded six new bisanthraquinones, together with four known related compounds. All compounds were tested for their antimicrobial activity (including antibacterial, antifungal and antiviral activities). All dimers were found to be highly active at minimal inhibitory concentrations (MIC) of 7–125 µg/mL. Of specific interest is the fact that the alterporriol-type dimers, alterporriol E and its atropisomer D, exhibited different activity patterns against similar pathogenic microorganisms.

The endophytic fungus Corynespora cassiicola was isolated from the leaf tissues of the Chinese mangrove medicinal plant Laguncularia racemosa. The EtOAc extract of the fungus, which was grown on solid rice medium, exhibited considerable cytotoxic activity against Hela cell line, as well as antimicrobial activity (when tested in vitro). Chemical investigation of the extract yielded twelve new secondary metabolites, including corynecassiicol A (1) and its isomer corynecassicol B (2), corynesidone D (3), seven octalactones, coryneoctalactone A-G (4-10) and two decalactones, xestodecalactone D and E (11 and 12), together with four known compounds. The structures of the isolated compounds were determined on the basis of one- and two-dimensional NMR spectroscopy as well as mass spectrometry.

Our recent reported data established mistletoe harvested from Cola acuminata Schott et Endl. as the most potent in terms of immunostimulation [1, 2]. Further bioassay-guided fractionation of the crude extract showed potency in the order of chloroform fraction >> ethylacetate fraction > n-hexane fraction [3]. Our continued efforts to isolate and characterize these active constituents led to the isolation of nine major compounds, epimeric β-carotenoids and eight lipophilic fractions. Two notable steroids, 5α-16, 16-dimethyl-androstan-17-one and 6β-hydroxy-17-oxo-4, 5-secoandrostan-4-oic acid were identified in the lipophilic fractions. A novel sesquiterpene-like compound; 2, 3-dimethoxy-benzo [a, b] cyclopentenyl-31, 31, 51-trimethyl pyran-4-carboxylic acid and an alkaloid, CFO were isolated from the chloroform fraction. Stigmast-7, 20 (21)-diene-3β-hydroxy-6-one, 3β-Hydroxy- stigmast- 23-ene (Stigmast-23-ene-3β-ol), 21β-hydroxy- 5, 9(10), 24-triene-21-nor-dammaren-3-one, lupeol and other steroids, HF4, HF6, HF7 were isolated from the n-hexane fraction while dibutyl phthalate and a flavonoidal EA2 were confirmed in the ethylacetate fraction. All isolated compounds were subjected to cell proliferation studies using cell line (C57Bl/6 splenocytes) and flow cytometry techniques against Lipopolysaccharide and Concanavalin A standards. The results showed that of all the major compounds isolated; only CFO, EA2 and HF7 exhibited immunostimulatory activity. Specifically, EA2 and CFO were the most potent with activity index of 91.49±0.22% and 69.84±0.19% respectively compared to 34.01±0.32% recorded for the two standards. The antioxidant potentials of these compounds showed that EA2 was most potent with an effective concentration (EC50) value of 55.42±0.99mg/ml against ascorbic acid value of 17.6±1.78mg/ml.

Extracts of the fungus Stemphylium globuliferum, an endophyte of the Moroccan medicinal plant Mentha pulegium, exhibited considerable cytotoxic and antimicrobial activities when tested in vitro. Chemical investigation of the extracts yielded four new secondary metabolites, including altersolanol K (1), altersolanol L (2), altersolanol M (3), and altersolanol N (4), together with the known compounds 6-O-methylalaternin (5), macrosporin (6), altersolanol A (7), tetrahydroaltersolanol B (8), altersolanol C (9), altersolanol J (10), stemphypyrone (11) and indole-3-carboxaldehyde (12). The structures of all compounds were determined on the basis of one- and two-dimensional NMR spectroscopy and mass spectrometry. Among the altersolanol derivatives tested, compound (3) was the most active congener against L5178Y cell line with an EC50 value of 1.14 µM. Moreover, all anthraquinones exhibited antibiotic activity against several pathogenic microbes. Interestingly, the new altersolanol N together with altersolanol C showed considerable antiviral activity against HRV39, whereas tetrahydroaltersolanol B was very active against HRV2, HRV8 and HRV16.

The endophytic fungus Stemphylium botryosum was isolated from leaves of the medicinal plant Chenopodium album collected in Egypt. Extracts of the fungus grown on rice exhibited considerable cytotoxicity when tested in vitro against L5178Y mouse lymphoma cells. Upon chemical investigation they afforded the macrocyclic lactones curvularin (1) and dehydrocurvularin (2), as well as altersolanol A (3), tetrahydroaltersolanol B (4), stemphyperylenol (5) and macrosporin (6). The structures of all isolated compounds were determined by 1D and 2D NMR spectroscopy and mass spectrometry as well as by comparison with published data. Compounds 1-3 exhibited considerable cytotoxicity against L5178Y cells with EC50 values of 16, 1.4 and 0.6 mu M, respectively, whereas the remaining compounds showed only modest activity. All compounds were further tested for protein kinase inhibitory activity in an assay involving 24 different kinases. Compound 3 was the most potent inhibitor displaying EC50 values ranging between 1.9 and 29.4 mu M toward individual kinases, followed by 6 (EC50 = 2.3 - 27.1 mu M). Compounds 4 and 5 showed moderate activity, while 1 and 2 were inactive.

The endophytic fungus Stemphylium globuliferum was isolated from stem tissues of the Moroccan medicinal plant Mentha pulegium. Extracts of the fungus, which was grown on solid rice medium, exhibited considerable cytotoxicity when tested in vitro against L5178Y cells. Chemical investigation yielded eight new secondary metabolites, alterporriol F, alterporriol G and its atropisomer H, alterporriol I and its atropisomer J, altersolanol K, altersolanol L and stemphypyrone, beside eight known compounds. The structures were determined on the basis of one- and two-dimensional NMR spectroscopy and mass spectrometry. Among the alterporriol-type anthranoid dimers, the mixture of alterporriols G and H exhibited considerable cytotoxicity against L5178Y cells with an EC50 value of 2.7 µg/mL, whereas the other congeners showed only modest activity. The compounds were also tested for protein kinase inhibitory activity in an assay involving 24 different kinases. Compounds methylalaternin, macrosporin, altersolanol A and the mixture of alterporriol G and H were the most potent and also selective inhibitors, displaying EC50 values between 0.64 and 1.4 µg/mL toward individual kinases.

In this study the chemical composition and oral acute toxicity of the essential oil of Mentha piperita L. growing in Morocco were investigated. The volatile extract was isolated using hydro-distillation technique followed by continuous liquid-liquid fractionation (Water / Ethyl acetate). The essential oil was then analyzed by gas chromatography (GC) and chromatography-mass spectroscopy (GC-MS). The major compounds which characterized the essential oil of this plant were linalool (1) (60.72 %) and its acetate (2) (20.79 %), as well as geraniol (3) (3.26 %), 1,8-cineol (4) (2.33 %) and limonene (5) (1.54%). The acute toxicity of Mentha piperita L. oil was investigated in mice. The total essential oil in form of suspension in water with Tween 80 was tested by gavage. Acute toxicity evaluation of this essential oil showed a mortality percentage of 0, 10, 30, 50, 70, 100 for the doses 250, 500, 1000, 2000, 3000, 4000 mg/kg body weight of mice, respectively. Moreover, the lethal amount 50 (LD50) of the essential oil of Mentha piperita L. was found to be 1612.45 mg/kg with confidence limits 1461.41 mg/kg and 1779.11 mg/kg.