Sorbicillinoid-Based Metabolites from a Sponge-Derived Fungus Trichoderma saturnisporum

Abstract

Antibacterial activity assessment and high performance liquid chromatography associated with nuclear magnetic resonance (HPLC/NMR) data revealed that the EtOAc extract of the fermented endophytic fungus Trichoderma saturnisporum DI-IA, obtained from the marine sponge Dictyonella incisa, contained conjugated olefinic metabolites with antibacterial activity. Chemical examination of the fungal strain resulted in the isolation of eight new sorbicillinoid-based compounds, namely saturnispols A–H (1–8). Their structures were determined on the basis of extensive spectroscopic analysis, including the experimental and calculated electronic circular dichroism (ECD) data for the configurational assignments. Saturnispol F exerted significant inhibition against a panel of bacteria strains including vancomycin-resistant enterococci (VRE) with a minimum inhibitory concentrations (MIC) ranging from 1.63 to 12.9 μg/mL, while saturnispol H showed selective effects against VRE and B. subtilis.

For a Correct Application of the CD Exciton Chirality Method: The Case of Laucysteinamide A

“…In many other cases, the transition dipole polarization may be inferred from the symmetry properties of the chromophores. For example, an all- trans polyene chain, or a polyenone, has an effective cylindrical symmetry for which the relevant π–π* transitions are necessary polarized along the chain direction; ECM applications are therefore straightforward [ 16 ]. On the contrary, the thiazoline ring lacks any element of axial symmetry, therefore π–π* transitions can be, in principle, oriented in any direction in the plane.…”

“…The most important quality of the ECM is its ease of application; it is also very robust, because it is based on a well-established theoretical basis [ 6 , 12 ]. These two facts render the ECM still popular, in the present computational era, to assign the AC of natural products including marine-derived ones, as demonstrated by a few recent references selected from this journal [ 16 , 17 , 18 , 19 , 20 , 21 ]. The method is so useful that when a compound lacks the necessary chromophores, it may be convenient to introduce them covalently or noncovalently to apply the ECM [ 15 , 22 ], rather than resorting to a different approach.…”

Antibiotics Development and the Potentials of Marine-Derived Compounds to Stem the Tide of Multidrug-Resistant Pathogenic Bacteria, Fungi, and Protozoa

“…Strains of E. faecalis A4 (VRE) were inhibited at MIC of 1.63 and 12.9 µg/mL, respectively, by only saturnispol F (6) and saturnispol H (8). These may be promising antibiotics for the treatment of Gram-negative bacterial infections [103]. An alkaloid-producing marine sponge (Epipolasis sp)-associated A. candidus KUFA0062 (Thailand) synthesized a previously unreported bis-indolyl benzenoid, candidusin D (2e), and a new hydroxypyrrolidine alkaloid, preussin C (5b), including another known fourteen compounds.…”

Novel Water-Soluble Photosensitizer for Photodynamic Inactivation of Gram-Positive Bacteria Using Nontoxic Dose of UV Light

“…Sorbicillinoids were divided into four classes based on their structure [32]: monomeric sorbicillinoids, bisorbicillinoids, trisorbicillinoids, and hybrid sorbicillinoids. In recent years, various potential applications of sorbicillinoids have been exploited, such as antioxidants [33,34], antibiotics [35,36], and anticancer drugs [37,38]. However, research on sorbicillinoids as a PS for the APDT system has not been reported.…”