Mersaquinone, A New Tetracene Derivative from the Marine-Derived Streptomyces sp. EG1 Exhibiting Activity against Methicillin-Resistant Staphylococcus aureus (MRSA)

Abstract

New antibiotics are desperately needed to overcome the societal challenges being encountered with methicillin-resistant Staphylococcus aureus (MRSA). In this study, a new tetracene derivative, named Mersaquinone (1), and the known Tetracenomycin D (2), Resistoflavin (3) and Resistomycin (4) have been isolated from the organic extract of the marine Streptomyces sp. EG1. The strain was isolated from a sediment sample collected from the North Coast of the Mediterranean Sea of Egypt. The chemical structure of Mersaquinone (1) was assigned based upon data from a diversity of spectroscopic techniques including HRESIMS, IR, 1D and 2D NMR measurements. Mersaquinone (1) showed antibacterial activity against methicillin-resistant Staphylococcus aureus with a minimum inhibitory concentration of 3.36 μg/mL.

Marine natural products

“…These metabolites were all C-4 epimers based on the julichrome Q 10 184 skeleton. 59 Analysis of various Streptomyces ferments afforded chlorinated 3-phenylpropanoic acid derivatives 188–190 , 60 MMP-1 secretion inhibitor sarmentosamide 191 , 61 a new anti-MRSA tetracene derivative, mersaquinone 192 , 62 hexacyclic xanthone ukixanthomycin A 193 , 63 butenolide mycenolide A 194 , 64 22-membered macrolides 195–197 , 65 angucycline derivatives, monacyclinones G–K 198–202 and ent -gephyromycin A 203 (ref. 66) and chromomycin A9 204 , which showed potent activity towards several microbial strains.…”

Recent exploration of bioactive pigments from marine bacteria

“…nov., along with three known compounds, actinosporins C, D, and G [22]. Mersaquinone, a new tetracene derivative that exhibits antibacterial activity against methicillin-resistant Staphylococcus aureus, was successfully characterized and reported [23].…”

Whole-genome sequence of bioactive streptomycete derived from mangrove forest in Malaysia, Streptomyces sp. MUSC 14

“…As a matter of fact, the continuous search for pharmaceutically important compounds led to another (one half jointly) Nobel Prize in Physiology or Medicine in 2015 awarded to Professor William C. Campbell and Professor Satoshi Ōmura for the discovery of avermectin, which was isolated from a soil streptomycete, Streptomyces avermitilis [22][23][24][25][26][27] . The search for bioactive compounds from this prolific genus seems like a never-ending journey, with researchers now hunt for them in unique environments such as hot springs, volcanic soils, deserts, deep-sea, and the mangrove forest [28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] . The hypothesis behind searching these special habitats is that microbes may come up with adaptation strategies to ensure their survival in the harsh condition like drastic temperature changes, salinity, and oxygen availability, which in turn may lead to the production of interesting compounds and drive the emergence of a novel bacterium [43][44][45][46][47][48][49][50] .…”