Antibacterial Meroterpenoids from the South China Sea Sponge <i>Dysidea</i> sp.

Abstract

Key words meroterpenoid; marine sponge; antibacterial activity; DysideaMarine organisms such as sponges represent a largely unexploited source of a wide variety of natural meroterpenoids.1) Sponges of the genus Dysidea are a rich source of bioactive meroterpenoids, the majority of which are sesquiterpene quinones/quinols.2) This class of compounds frequently consist of sesquiterpene moieties linked to quinones, quinols, or structural analogues.3) The sesquiterpene unit is of biosynthetic interest, as it usually features a drimane-or a 4,9-friedodrimane-type skeleton comprising a trans-or a less common cis-fused ring junction.3) These compounds have attracted much interest due to their structural diversity and varied biological activities, including anti-human immunodeficiency virus (HIV), 4) antibacterial, 5) antifungal, 6) antioxidative, 7) antitumor, 8) anti-inflammatory, 9) inhibition against protein tyrosine kinase (PTK) and protein tyrosine phosphatase 1B (PTP1B), 10,11) and activation of hypoxia-inducible factor-1 (HIF-1) activities. 12)During our search for bioactive metabolites from tropical sponges, we encountered a purple-colored encrusting Dysidea sp. off the south China sea. The crude extract of this sponge showed significant antibacterial activity against Staphylococcus aureus (25923) with the minimum inhibitory concentration (MIC) value of 25 µg/mL. Chemical investigation of bioactive extracts of this sponge led to the isolation of three new sesquiterpene phenols (1−3) and one new sesquiterpene aminoquinone (4), together with four known sesquiterpene derivatives (5−8). Herein, we report the details of the purification and structure elucidation of these compounds, as well as the evaluation of antibacterial activity (Fig. 1). Results and Discussion

Marine natural products

“…445) as did three different collections of Dysidea (920-930). [446][447][448] Only two meroditerpenoids 931 and 932 were reported in 2016, 449 while sesquiterpenoids, their formamides, isocyanides, thiocyanates, isothiocyanates and dimers 933-947 (ref. [450][451][452] were reported from Axinyssa, Dysidea and Halichondria sponges; 944 is a known synthetic compound.…”

1,4-Benzoquinone antimicrobial agents against Staphylococcus aureus and Mycobacterium tuberculosis derived from scorpion venom

“…Compounds with the 1,4-benzoquinone motif are a large class of molecules distributed throughout nature. They are highly reactive, acting as both oxidants and Michael acceptors, and many have been serendipitously found to have antimicrobial, antineoplastic, anticoagulant, and analgesic activity (26)(27)(28)(29)(30)(31)(32). In this work, we describe two 1,4-benzoquinone compounds, one red, the other blue, which are derived from naturally occurring precursors in the venom of D. melici, a scarcely studied species of scorpion which is indigenous to Mexico.…”

Bioactive Prenyl- and Terpenyl-Quinones/Hydroquinones of Marine Origin †

“…They were isolated from a purple-colored encrusting Dysidea sp. off the coral-reef near Yongxing Island in the South China Sea, and showed weak antibacterial activity against E. coli , B. subtilis and S. aureus [ 66 ].…”

“…collected off the coral-reef near Yongxing Island in the South China Sea, mentioned above for being a source of drimane meroterpenoids, was also a source of avarane aminoquinone derivatives with a Δ 4(14) double bond in a trans -decaline: smenospongine ( 176 ), smenospongorine ( 178 ), smenospongiarine ( 179 ), smenospongidine ( 180 ), and the new derivative smenospongimine ( 177 ) ( Table 3 ). All of them showed potent antibacterial activities [ 66 ].…”