Antioxidant Potential of Five Compounds Extract From the Marine Fungus Aspergillus Flocculosus by DFT Method: Hat and Set Mechanism.

Abstract

Antioxidant potential of five compounds include ochraceopone F (1), aspertetranone D (2), cycloechinulin (3), wasabidienone E (4) and mactanamide (5) in the extracts from marine fungus Aspergillus flocculosus in Nha Trang was investigated by computational chemistry methods. All calculations were performed at the theoretical level M05-2X/6-311++G(d, p)//M05-2X/6-31+G(d) in the gas phase. The physicochemical properties such as bond dissociation energies (BDE), ionization energies (IE), electron affinity (EA) characterizing HAT (Hydrogen atom transfer) and SET (Single electronic transfer) antioxidant mechanisms were calculated.As a result, the H-atom donating ability of the studies compounds increases in the descending order of BDE value (1) > (2) > (3) > (4) » (5). Wherein the compounds (4) and (5) represent as the most potential antioxidant with the lowest BDE in the gas phase being 74.9 and 75.1 kcal/ mol. Moreover, the electronic donating ability of the compounds increases as function of the descending order of IE value (2) > (1) > (5) > (3) > (4). And the electron accepting abitlity decreases in decreasing EA value (4) > (3) > (2) > (5) > (1). Compound (4) (wasabidienone E) has the smallest IE value of 6.56 eV and has the largest EA value of 2.33 eV.

Screening of antibacterial and antioxidant activities of marine fungi isolated from the North Sea of Vietnam

“…According to our previous investigation, crude extracts from marine fungal strains obtained from Nha Trang bay could reduce DPPH and ABTS free radicals with a proportion of 61.5% and 80.3%, respectively [14]. Interestingly, five antioxidant compounds such as ochraceopone F, aspertetranone D, cycloechinulin, wasabidienone E, and mactanamide were found in the spongederived fungus Aspergillus flocculosus from Nha Trang bay [15].…”

“…Due to the increasing demand for new antibiotics mechanism of action, antibacterial activity is one of the looks of the properties of marine fungi [12,13]. Besides, recent studies have confirmed marine fungi are a valuable source of antioxidant compounds with potent biological activity and various structural features, promising sources of novel bioactive compounds [14,15]. Hence, in this study, we evaluated the potential antibiotic and antioxidant activities of marine fungi isolated during the field survey on the Akademik Oparin vessel in 2021.…”