Bioactive Secondary Metabolites from Fungi of the Genus Cytospora Ehrenb. (Ascomycota).

Cytospora is a genus of fungi belonging to the Cytosporaceae family (Sordariomycetes, Ascomycota) considered as a prolific source of specialized metabolites due to their ability to produce diverse secondary metabolites with a broad range of biological activities. Since the first chemical investigation of this genus in the 1980s, further studies have led to the isolation and structural elucidation of several bioactive compounds including cytosporones, nonanolides, macrocyclic dilactones, and terpenoids. This review summarizes, for the first time, the chemical diversity of bioactive secondary metabolites from the genus Cytospora and highlights its potential as an alternative source of secondary metabolites for pharmacological studies. Moreover, this review will serve as a basis for future investigations of compounds of this genus.

Antimicrobial and Cytotoxic Activities of Constituents from the Fruit of Albizia lebbeck L. Benth (Fabaceae).

Twenty-two compounds were isolated from the fruit of Albizia lebbeck including one unprecedented, rare amino acid-derived zwitterionic and one new flavone derivative. The isolation was performed on repeated column chromatography over silica gel and their structures were determined by 1D-, 2D-NMR and HR-ESI-MS spectra together with reported data in the literature. The chemophenetic significance is also discussed. Some isolated compounds were reported for the first time to be found in the species. Additionally, compound 2 showed antibacterial activity and compounds 1 and 2 revealed moderate cytotoxic activity against the Raw 264.7 cancer cell line with IC50 values of 37.19 µM and 29.36 µM, respectively. Furthermore, a proposed biosynthetic pathway of compound 1 is described.

Antibacterial Flavonoids and Other Compounds from the Aerial Parts of Vernonia guineensis Benth. (Asteraceae).

An extensive phytochemical study of the aerial parts of Vernonia guineensis Benth. (Asteraceae) led to the isolation of a new flavone, vernoguinoflavone and a naturally isolated glycerol ester, eicosanoic acid 2-hydroxy-1,3-propanediyl ester, together with eighteen known secondary metabolites including quercetin, luteolin, vernopicrin, vernomelitensin, ß-amyrin, oleanolic acid, ursolic acid, lupeol, betulinic acid, ß-carotene, a mixture of stigmasterol and ß-sitosterol, ß-sitosterol-3-O-ß-D-glucoside, 2,3-dihydroxypropyl heptacosanoate, pentacosanoic acid, docosan-1-ol, tritriacontan-1-ol, and heptatriacontan-1-ol. Eleven compounds are reported herein for the first time from this species. The structures of these compounds were elucidated on the basis of extensive spectroscopic analyses, particularly 1D and 2D NMR, and HR-ESI-MS and by comparison of their data with those reported in the literature. The crude extract, fractions and some isolated compounds were evaluated for their antibacterial activity against Gram-negative bacteria: Escherichia coli (ATCC 25922), Shigella flexineri (NR 518), Salmonella muenchen, Salmonella typhimurium and Salmonella typhi (ATCC 19430). All the tested compounds demonstrated inhibitory activities against the tested enteric bacteria with MIC values ranging from 3.12 to 100 µg/ml. Three flavonoids isolated from the most active fraction demonstrated the best bioactivities against Escherichia coli, Salmonella muenchen and Salmonella typhimurium with MIC values ranging from 3.12 to 25 µg/mL.

Phytochemistry and pharmacology of the genus Entandrophragma over the 50 years from 1967 to 2018: a 'golden' overview.

OBJECTIVES: For centuries, the genus Entandrophragma (Meliaceae), endemic to Africa, has been used in traditional medicine for the treatment of several illnesses. This review deals with large range of phytochemicals from the genus Entandrophragma and their pharmacological potentials covering the period from 1967 to 2018. KEY FINDINGS: Phytochemical investigations of the genus Entandrophragma led to the report of about 166 secondary metabolites which have been thoroughly summarized herein including some of their semisynthetic derivatives obtained from chemical transformations as well as their biological activities in the medicinal and agricultural domains. The limonoids or meliacins and their precursor called protolimonoids (protomeliacins) reported so far represent almost 69.28% of the total secondary metabolites obtained from the genus, and they display the most potent biological activities. Collectively, both classes of metabolites constitute the markers of Entandrophragma. However, squalene-type triterpenoids and sesquiterpenoids were reported only from the species E. cylindricum and therefore could be its chemotaxonomic markers. SUMMARY: The pharmacological investigations of the extracts of some species exhibited interesting results which support the traditional uses of these Entandrophragma plants in folk medicine. Some compounds revealed promising antiplasmodial and anti-inflammatory activities and deserve therefore further attention for new drug discovery.