Secondary Metabolites from an Actinomycete from Vietnam's East Sea

Abstract

Analysis of an antimicrobial extract prepared from culture broth of the marine-derived actinomycete Nocardiopsis sp. (strain G057) led to the isolation of twelve compounds, 1-12. Compound 1 (2-[(2R-hydroxypropanoyl)amino]benzamide) was found to be a new enantiomeric isomer while compounds 2 (3-acetyl-4-hydroxycinnoline) and 3 (3,3'-bis-indole) were isolated from a natural source for the first time. The structures of 1-12 were determined by analyses of MS and 2D NMR data. All compounds were evaluated for their antimicrobial activity against a panel of clinically significant microorganisms. Compound 1 selectively inhibited Escherichia coli (MIC: 16 µg/mL). Compounds 2 and 3 exhibited antimicrobial activity against several strains of both Gram-positive and Gram-negative bacteria, and the yeast Candida albicans. Cytotoxic evaluation of compounds 1-3 against four cancer cell lines (KB, LU-1, HepG-2 and MCF-7) indicated that compound 3 produced a weak inhibition against KB and LU cell lines. Two remaining compounds, 1 and 2 were not cytotoxic, even at the concentration of 128 μg/mL.

New Antiproliferative Compounds against Glioma Cells from the Marine-Sourced Fungus Penicillium sp. ZZ1750

“…Based on the NMR data and optical rotation values as well as the comparison with the reported data, compounds 8-17 were identified as known compounds methyl linoleate (8) [30], 12β-hydroxyverruculogen TR-2 (9) [31,32], 12β-hydroxy-13α-methoxyverruculogen TR-2 (10) [31,33], cyclotryprostatin B (11) [34], verruculogen (12) [34], fumiquinazoline C (13) [35], fumiquinazoline J (14) [35,36], brevianamide F (15) [37,38], 2-[(2R-hydroxypropanoyl)amino] benzamide (16) [39], and trypacidin (17) [40,41]. The 13 C and 1 H NMR data of compounds 8-17 are reported in Tables S9-S13.…”

Chemical Composition and Biological Activities of Metabolites from the Marine Fungi Penicillium sp. Isolated from Sediments of Co To Island, Vietnam

“…The ethyl acetate-soluble fraction from M30 was applied to several chromatography techniques such as silica gel, reverse phase-18, and semi-preparative HPLC, resulting in the isolation of ten secondary metabolites ( 1 – 10 ) (Figure 2). The known compounds, sporogen AO-1 ( 1 ) [22], 3-indolecarbadehyde ( 2 ) [22], 2-[(5-methyl-1,4-dioxan-2-yl)methoxy]ethanol ( 3 ) [23], 2-[(2 R -hydroxypropanoyl)amino]benzamide ( 4 ) [23], 4-hydroxybenzandehyde ( 5 ) [24], chrysogine ( 6 ) [24], acid 1H-indole-3-acetic ( 8 ) [25], and cyclo (Tyr-Trp) ( 9 ) [26], and 2’,3’-dihydrosorbicillin ( 10 ) [26] (Figure 2), were elucidated by the examination of their NMR spectra and comparison with literature data.…”

Flavonoids and Alkaloids from Marine‐Derived Actinomycete Streptomyces sp. C011

“…A negative Cotton effect at 292 nm (Δ -5.9), and a positive Cotton effect at 312 nm (Δ +0.9) were observed in the CD spectrum of 1 revealing the S-configuration for carbon C-2. [6][7][8] Consequently, the structure of 1 was elucidated as 6-lavandulyl-5,7,2′,4′tetrahydroxyflavanone. [8][9] Compound 2 was obtained as an optically active 2).…”