title: Antifouling 26,27-cyclosterols from the Vietnamese marine sponge Xestospongia testudinaria.
abstract: Three new C29 sterols with a cyclopropane ring cyclized between C-26 and C-27 of the side chain, aragusterol I (1), 21-O-octadecanoyl-xestokerol A (4), and 7β-hydroxypetrosterol (5b), were isolated from the Vietnamese marine sponge Xestospongia testudinaria, along with the known compounds, aragusterol B (2), xestokerol A (3), 7α-hydroxypetrosterol (5a), 7-oxopetrosterol (6), and petrosterol (7). The structures of the new compounds were established by analysis of spectroscopic data including 1D and 2D NMR, and high-resolution electrospray ionization mass spectrometry (HRESIMS). Their capacity to inhibit the adhesion of isolated bacteria from marine biofilms was evaluated against the bacterial strains Pseudoalteromonas sp. D41, Pseudoalteromonas sp. TC8, and Polaribacter sp. TC5. Aragusterol B (2) and 21-O-octadecanoyl-xestokerol A (4) exhibited the most potent antifouling activity with EC50 values close to these reported in the literature for tributyltin oxide, a marine anti-biofouling agent now considered to be a severe marine pollutant. Due to its comparable activity to tributyltin oxide and its absence of toxicity, the new 26,27-cyclosterol, 21-O-octadecanoyl-xestokerol A (4) constitutes a promising scaffold for further investigations.
authors.affiliation: Institute of Marine Biochemistry, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Caugiay, Hanoi, Vietnam.
authors.forename: Xuan Cuong
authors.initials: XC
authors.lastname: Nguyen
authors.forename: Arlette
authors.initials: A
authors.lastname: Longeon
authors.forename: Van Cuong
authors.initials: VC
authors.lastname: Pham
authors.forename: Félix
authors.initials: F
authors.lastname: Urvois
authors.forename: Christine
authors.initials: C
authors.lastname: Bressy
authors.forename: Thi Thanh Van
authors.initials: TT
authors.lastname: Trinh
authors.forename: Hoai Nam
authors.initials: HN
authors.lastname: Nguyen
authors.forename: Van Kiem
authors.initials: VK
authors.lastname: Phan
authors.forename: Van Minh
authors.initials: VM
authors.lastname: Chau
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Briand
authors.forename: Marie-Lise
authors.initials: ML
authors.lastname: Bourguet-Kondracki
mesh_terms: D000818:Animals; D057219:Biofouling / Q000517:prevention & control*; D008386:Marine Biology; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D031161:Pseudoalteromonas / Q000187:drug effects; D013261:Sterols / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D014744:Vietnam; D047131:Xestospongia / Q000737:chemistry*
chemical_list: D013261:Sterols; C584072:aragusterol I