During our search for Streptomyces spp. as new producers of bioactive secondary metabolites, the ethyl acetate extract of the new terrestrial Streptomyces isolate TN262 delivered eight antimicrobially active compounds. They were identified as 1-acetyl-β-carboline (1), tryptophol (2), cineromycin B (3), 2,3-dihydrocineromycin B (4), cyclo-(tyrosylprolyl) (5), 3-(hydroxyacetyl)-indole (6), brevianamide F (7), and cis-cyclo-(l-prolyl-l-leucyl) (8). Three further metabolites were detected in the unpolar fractions using GC–MS and tentatively assigned as benzophenone (9), N-butyl-benzenesulfonamide (10), and hexanedioic acid-bis-(2-ethylhexyl) ester (11). This last compound is known as plasticizer derivatives, but it has never been described from natural sources. In this article, we describe the identification of the new Streptomyces sp. isolate TN262 using its cultural characteristics, the nucleotide sequence of the corresponding 16S rRNA gene and the phylogenetic analysis, followed by optimization, large-scale fermentation, isolation of the bioactive constituents, and determination of their structures. The biological activity of compounds (2), (3), (4), and those of the unpolar fractions was addressed as well.

The chemical composition and biological activity of three parts (rind, flesh and seeds) of pumpkin fruits (Cucurbita pepo L.) cultivated in Egypt were studied. Chemical analysis of fibre, protein, β-carotene, carbohydrates, minerals and fatty acids present in the rind, flesh, seeds and defatted seeds meal was conducted. Chemical, GC-MS and biological assays of organic extracts of the main fruit parts, rind and flesh established their unique constituents. Chromatographic purification of the extracts afforded triglyceride fatty acid mixture (1), tetrahydro-thiophene (2), linoleic acid (3), calotropoleanly ester (4), cholesterol (5) and 13(18)-oleanen-3-ol (6). GC-MS analysis of the extract's unpolar fraction revealed the existence of dodecane and tetradecane. Structures of the isolated compounds (1–6) were confirmed by NMR and EI-MS spectrometry. Antimicrobial, antiviral and antitumour activities of the fruit parts were discussed. The promising combined extract of rind and flesh was biologically studied for microbial and cytotoxic activities in comparison with the whole isolated components.

Eight bioactive pyrone derivatives were identified from the culture of Alternaria alternata strain D2006, isolated from the marine soft coral Denderonephthya hemprichi, which was selected as its profound antimicrobial activities. The compounds were assigned as pyrophen (1), rubrofusarin B (2), fonsecin (3), and fonsecin B (5) beside to the four dimeric naphtho-γ-pyrones; aurasperone A (6), aurasperone B (7), aurasperone C (8), and aurasperone F (9). Structures of the isolated compounds were identified on the basis of 1D and 2D NMR spectroscopy and mass (EI, ESI, HRESI) data, and by comparison with the literature. Configuration of the four dimeric naphtho-γ-pyrones 6-9 was analyzed by CD spectra, exhibiting an identical stereochemistry.