Mansouramycins E-G, Cytotoxic Isoquinolinequinones from Marine Streptomycetes.

Chemical investigation of the ethyl acetate extract from the marine-derived sp. isolate B1848 resulted in three new isoquinolinequinone derivatives, the mansouramycins E-G (-), in addition to the previously reported mansouramycins A () and D (). Their structures were elucidated by computer-assisted interpretation of 1D and 2D NMR spectra, high-resolution mass spectrometry, and by comparison with related compounds.

Sulochrins and alkaloids from a fennel endophyte sp. FVL2.

The fungal endophyte sp. strain FVL2, isolated from the traditional medicinal fennel plant, , was investigated for secondary metabolites. Fermentation on rice medium followed by chromatographic separation delivered three new natural products, 7-demethyl-neosulochrin (), fumigaclavine I () and -benzoyl-tryptophan () together with further 14 known metabolites, 1--methyl-sulochrin-4'-sulfate, questin, laccaic acid, isorhodoptilometrin, fumigaclavine A, fumigaclavine C, fumitremorgin C, fumigaquinazoline C, tryptoquivaline J, trypacidin, 3'--demethyl-sulochrin, 1--methyl-sulochrin, protocatechuic acid, and vermelone.

New Haloterpenes from the Marine Red Alga : Structure Elucidation and Biological Activity.

Analysis of the air-dried marine red alga , collected near Ras-Bakr at the Suez gulf (Red Sea) in Egypt delivered five new halogenated terpene derivatives: aplysiolic acid (), 7-acetyl-aplysiol (), aplysiol-7-one (), 11,14-dihydroaplysia-5,11,14,15-tetrol (), and a new maneonene derivative , named 5--maneolactone. The chemical structures of these metabolites were characterized employing spectroscopic methods, and the relative and absolute configurations were determined by comparison of experimental and ab initio-calculated NMR, NOE, ECD, and ORD data, and by X-ray diffraction of and . The antimicrobial activities of the crude extract and compounds -, and were studied.

Boshramycinones A-C: New anthracyclinones produced by a marine-derived sp.: isolation, structure elucidation and biological activities.

Boshramycinones A-C (), three new anthracyclinones, were isolated from the culture broth of the marine-derived sp. Mei 16-1,2 together with 2-acetyl-1,8-dihydroxy-3-methyl-anthraquinone () and bafilomycins B1, B2, and C1-amide. The isolated compounds were identified by NMR spectroscopy and mass spectrometry, the absolute configuration of was determined by comparison of experimental and calculated chiroptical data.

Isolation, Synthesis And Structure Determination Of Cannabidiol Derivatives And Their Cytotoxic Activities.

In a continuing effort to explore the structural diversity and pharmacological activities of natural products based scaffolds, herein, we report the isolation, synthesis, and structure determination of cannabidiol and its derivatives along with their cytotoxic activities. Treatment of cannabidiol () with acid catalyst POCl afforded a new derivative along with six known molecules -, and, . The structure of was elucidated by extensive spectroscopic analyses and DFT calculations of the NMR and ECD data.