ABSTRACT
A cytotoxic alkaloidal meroterpenoid, saccharoquinoline (1), has been isolated from the fermentation broth of the marine-derived bacterium Saccharomonospora sp. CNQ-490. The planar structure of 1 was elucidated by 1D, 2D NMR, and MS spectroscopic data analyzes, while the relative configuration of 1 was defined through the interpretation of NOE spectroscopic data. Saccharoquinoline (1) is composed of a drimane-type sesquiterpene unit in combination with an apparent 6,7,8-trihydroxyquinoline-2-carboxylic acid. This combination of biosynthetic pathways was observed for the first time in natural microbial products. Saccharoquinoline (1) was found to have cytotoxicity against the HCT-116 cancer cell line by inducing G1 arrest, which leads to cell growth inhibition.
Subject(s)
Actinobacteria/metabolism , Antineoplastic Agents/pharmacology , Terpenes/chemistry , Terpenes/pharmacology , Actinobacteria/chemistry , Antineoplastic Agents/chemistry , Cell Line, Tumor , Cell Survival/drug effects , Humans , Models, Molecular , Molecular StructureABSTRACT
Intensive study of the organic extract of the marine-derived bacterium Saccharomonospora sp. CNQ-490 has yielded three new α-pyrones, saccharomonopyrones A-C (1-3). The chemical structures of these compounds were assigned from the interpretation of 1D, 2D NMR and mass spectrometry data. Saccharomonopyrone A (1) is the first α-pyrone microbial natural product bearing the ethyl-butyl ether chain in the molecule, while saccharomonopyrones B and C possess unusual 3-methyl and a 6-alkyl side-chain within a 3,4,5,6-tetrasubstituted α-pyrone moiety. Saccharomonopyrone A exhibited weak antioxidant activity using a cation radical scavenging activity assay with an IC50 value of 140 µM.
Subject(s)
Actinomycetales/chemistry , Biological Products/isolation & purification , Geologic Sediments/chemistry , Pyrones/isolation & purification , Biological Products/chemistry , Marine Biology , Molecular Structure , Pyrones/chemistryABSTRACT
HPLC-UV guided isolation of the culture broth of a marine bacterium Saccharomonospora sp. CNQ-490 has led to the isolation of two new natural products, lodopyridones B and C (1 and 2) along with the previously reported lodopyridone A (3). Their chemical structures were established from the interpretation of 2D NMR spectroscopic data and the comparison of NMR data with the lodopyridone A (3). Lodopyridones B and C (1 and 2) possess the thiazole, and chloroquinoline groups which are characteristic features of these molecules. Lodopyridones A-C show weak inhibitory activities on the ß-site amyloid precursor protein cleaving enzyme 1 (BACE1).
