Terretonin N: A New Meroterpenoid from Nocardiopsis sp.

Hamed A, Abdel-Razek AS, Frese M, et al. Terretonin N: A New Meroterpenoid from Nocardiopsis sp. Molecules. 2018;23(2): 299.Terretonin N (1), a new highly oxygenated and unique tetracyclic 6-hydroxymeroterpenoid, was isolated together with seven known compounds from the ethyl acetate extract of a solid-state fermented culture of Nocardiopsis sp. Their structures were elucidated by spectroscopic analysis. The structure and absolute configuration of 1 were unambiguously determined by X-ray crystallography. The isolation and taxonomic characterization of Nocardiopsis sp. is reported. The antimicrobial activity and cytotoxicity of the strain extract and compound 1 were studied using different microorganisms and a cervix carcinoma cell line, respectively

Diverse polyketides and alkaloids from Penicillium sp. KHMM: structural elucidation, biological and molecular docking studies.

Hamed A, Ismail M, El-Metwally MM, et al. Diverse polyketides and alkaloids from Penicillium sp. KHMM: structural elucidation, biological and molecular docking studies. Zeitschrift für Naturforschung C. 2019;74(5-6):131-137

New oxaphenalene derivative from marine-derived Streptomyces griseorubens sp ASMR4

Hamed A, Abdel-Razek AS, Frese M, et al. New oxaphenalene derivative from marine-derived Streptomyces griseorubens sp ASMR4. Zeitschrift für Naturforschung B. 2017;72(1):53-62.During our search for novel bioactive compounds from extremophilic actinomycetes, the new Streptomyces griseorubens sp. ASMR4 was isolated from a soft coral collected in the Red Sea at the Hurghada coast, Egypt, and characterized taxonomically. It was fermented on large scale using a modified solid rice medium as the first example for actinomycetes so far. Work-up and purification of the strain extract using different chromatographic techniques afforded the new oxaphenalene derivative, 8-hydroxy-2-(2-hydroxypropyl)-7-acetyl-1-oxaphenalene (1a), together with seven known metabolites: ferulic acid (2), glycerol linoleate, linoleic acid methyl ester, (3R,4R)-3,4-dihydroxy-3-methylpentan-2-one/(3S,4R)-3,4-dihydroxy-3-methylpentan-2-one, anthranilic acid, phenylacetic acid, and benzoic acid. The chemical structure of the new compound (1a) was confirmed by extensive 1D and 2D NMR spectroscopy, high-resolution electron impact mass measurements, and by comparison with literature data. The antimicrobial activity of the strain extract and compounds 1a and 2 were studied using a panel of pathogenic microorganisms. The in vitro cytotoxicity of the bacterial extract was studied against the human cervix carcinoma cell line (KB-3-1) and its multidrug-resistant subclone (KB-V1)

N-Acetylborrelidin B: a new bioactive metabolite from Streptomyces mutabilis sp MII

Hamed A, Abdel-Razek AS, Frese M, et al. N-Acetylborrelidin B: a new bioactive metabolite from Streptomyces mutabilis sp MII. Zeitschrift für Naturforschung C. 2018;73(1-2):49-57.In the course of our screening program for new bioactive compounds, a naturally new 18-membered macrolide antibiotic, N-acetylborrelidin B (1) along with borrelidin (2) were obtained from the marine Streptomyces mutabilis sp. MII. The strain was isolated from a sediment sample collected in the Red Sea at the Hurghada Coast and characterized taxonomically. Additional nine diverse bioactive compounds were reported: 6-prenyl-indole-3-acetonitrile (3), sitosteryl-3 ss-d-glucoside, campesterol, ferulic acid, linoleic acid methyl ester, linoleic acid, N-acetylanthranilic acid, indole 3-acetic acid methyl ester, indole 3-carboxylic acid, and adenosine. Structure 1 was confirmed by in-depth NMR studies and by mass spectra, and comparison with related literature data. The antimicrobial activity of the strain extract and compounds 1 and 2 were studied using a panel of pathogenic microorganisms. The in vitro cytotoxicity of compounds 1 and 2 as well as the crude extract were tested against the human cervix carcinoma cell line (KB-3-1)