Fungus Aspergillus Flocculosus Research Articles

Unearthing the Potential Secondary Metabolites Isolated from the Fungus Aspergillus flocculosus : A Comprehensive Review.

Unearthing the Potential Secondary Metabolites Isolated from the Fungus Aspergillus flocculosus : A Comprehensive Review.

Asperflomide and asperflosamide, new N-methylated cyclopeptides from the marine sponge-derived fungus Aspergillus flocculosus 16D-1

Two new N-methylated cyclopeptides, asperflomide (1) and asperflosamide (2), were obtained from the marine sponge-derived fungus Aspergillus flocculosus 16D-1. The planer structure were determined by NMR spectroscopic data and the absolute configurations of the amino acids were elucidated by the Marfey's analysis. These cyclopeptides showed weak tankyrase1/2 inhibitory activity at the centration of 40 μM.

Two New Phomaligols from the Marine-Derived Fungus Aspergillus flocculosus and Their Anti-Neuroinflammatory Activity in BV-2 Microglial Cells.

Two new phomaligols, deketo-phomaligol A (1) and phomaligol E (2), together with six known compounds (3–8) were isolated from the culture broth of the marine-derived fungus Aspergillus flocculosus. Compound 1 was first isolated as a phomaligol derivative possessing a five-membered ring. The structures and absolute configurations of the new phomaligols were determined by detailed analyses of mass spectrometry (MS), nuclear magnetic resonance (NMR) data, optical rotation values and electronic circular dichroism (ECD). In addition, the absolute configurations of the known compounds 3 and 4 were confirmed by chemical oxidation and comparison of optical rotation values. Isolated compounds at a concentration of 100 μM were screened for inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-induced BV-2 microglial cells. Among the compounds, 4 showed moderate anti-neuroinflammatory effects with an IC50 value of 56.6 μM by suppressing the production of pro-inflammatory mediators in activated microglial cells without cytotoxicity.

Asperfloketals A and B, the First Two Ergostanes with Rearranged A and D Rings: From the Sponge-Associated Aspergillus flocculosus 16D-1.

Asperfloketals A (1) and B (2), two 1(10 → 6)-abeo-14,15-secosteroids featuring a novel trioxahexaheterocyclic ring system, were isolated from the sponge-associated fungus Aspergillus flocculosus 16D-1. Their structures were elucidated by extensive spectroscopic analysis and NMR chemical shifts calculations, supported by DP4+ probability analysis, and their absolute configurations were determined by ECD calculations and the modified Mosher's method. Asperfloketals A and B showed strong anti-inflammatory activity in the CuSO4-induced transgenic fluorescent zebrafish but displayed no cytotoxicity against HeLa, HepG2, and SW480 cell lines.

Antimicrobial activity of natural compounds from sponge – derived fungus Aspergillus flocculosus 01NT.1.1.5

The Aspergillus fungi have been an important source of natural products that are useful for exploration in medicine, agriculture and industry. In our continuous investigation to search for new antimicrobial agents from marine-derived fungi, one new phomaligol A2 (1), together with three known compounds, wasabidienone E (2), aspertetranone D (3) and mactanamide (4), were obtained from the EtOAc extract of the culture medium of the marine-derived fungus Aspergillus flocculosus (A. flocculosus) 01NT.1.1.5 isolated from the sponge Stylissa sp. at Nhatrang Bay, Vietnam. Their chemical structures were elucidated by analysis of 1D and 2D NMR and mass spectroscopic data, as well as by comparison of the corresponding data to those previously reported in the literature. Furthermore, the aim of this study was also to evaluate the antimicrobial activity of these compounds against pathogenic microbes including Escherichia coli (E. coli) ATCC 25922, Pseudomonas aeruginosa (P. aeruginosa) ATCC 27853, Staphylococcus aureus (S. aureus) ATCC 25923, Bacillus cereus (B. cereus) ATCC 11778, Streptococcus faecalis (S. faecalis) ATCC 19433, Listeria monocytogenes (L. monocytogenes) ATCC 19111, and Candida albicans (C. albicans) ATCC 10231. Among the compounds, 1-3 were inhibitory on the growth of the yeast C. albicans with minimum inhibitory concentration (MIC) value of 16 μg/mL, which was more potent than amoxicillin and cefotaxime (MIC > 256 μg/mL), antimicrobial drugs as positive references. Moreover, compounds 1-4 were also found to be active against other pathogens including P. aeruginosa and S. faecalis with MIC values of 16 μg/mL and 32 μg/mL, respectively. Compound 4 had no inhibitory activity against L. monocytogenes, whereas compounds 1-3 had ability to against this strain with MICs of 32 to 64 μg/mL. Four of tested compounds exhibited antibacterial activity against B. cereus and E. coli with MIC values of 64-128 μg/mL. This is the first report about these compounds with antimicrobial activity obtained from marine fungus A. flocculosus isolated in Vietnam.

Biologically Active Metabolites from the Marine Sediment-Derived Fungus Aspergillus flocculosus.

Four new compounds were isolated from the Vietnamese marine sediment-derived fungus Aspergillus flocculosus, one aspyrone-related polyketide aspilactonol G (2), one meroterpenoid 12-epi-aspertetranone D (4), two drimane derivatives (7,9), together with five known metabolites (1,3,5,6,8,10). The structures of compounds 1–10 were established by NMR and MS techniques. The absolute stereoconfigurations of compounds 1 and 2 were determined by a modified Mosher’s method. The absolute configurations of compounds 4 and 7 were established by a combination of analysis of ROESY data and coupling constants as well as biogenetic considerations. Compounds 7 and 8 exhibited cytotoxic activity toward human prostate cancer 22Rv1, human breast cancer MCF-7, and murine neuroblastoma Neuro-2a cells.

New Ophiobolin Derivatives from the Marine Fungus Aspergillus flocculosus and Their Cytotoxicities against Cancer Cells

Five new sesterterpenes, 14,15-dehydro-6-epi-ophiobolin K (1), 14,15-dehydro- ophiobolin K (2), 14,15-dehydro-6-epi-ophiobolin G (3), 14,15-dehydro-ophiobolin G (4) and 14,15-dehydro-(Z)-14-ophiobolin G (5), together with four known ophiobolins (6–9) were isolated from the marine fungus Aspergillus flocculosus derived from the seaweed Padina sp. collected in Vietnam. The five new ophiobolins were first isolated as ophiobolin derivatives consisting of a fully unsaturated side chain. Their structures were elucidated via spectroscopic methods including 1D, 2D NMR and HR-ESIMS. The absolute configurations were determined by the comparison of chemical shifts and optical rotation values with those of known ophiobolins. All compounds (1–9) were then evaluated for their cytotoxicity against six cancer cell lines, HCT-15, NUGC-3, NCI-H23, ACHN, PC-3 and MDA-MB-231. All the compounds showed potent cytotoxicity with GI50 values ranging from 0.14 to 2.01 μM.

ANTIOXIDANT POTENTIAL OF FIVE COMPOUNDS EXTRACT FROM THE MARINE FUNGUS ASPERGILLUS FLOCCULOSUS BY DFT METHOD: HAT AND SET MECHANISM.

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.

Ochrasperfloroid, an ochratoxin-ergosteroid heterodimer with inhibition of IL-6 and NO production from Aspergillus flocculosus 16D-1.

A novel ochratoxin–ergosteroid heterodimer, ochrasperfloroid (1), together with a known mycotoxin, ochratoxin A (2), were isolated from the sponge-derived fungus Aspergillus flocculosus 16D-1. The structure of 1 was determined on the basis of 1D/2D NMR, HRESIMS/MS, and LC-UV/MS analysis of its alkaline hydrolyzates, quantum-chemical 13C NMR calculation, and comparison with literature data. Of note, the ergosteroid embedded in 1 is also a new structure. Ochrasperfloroid (1) showed potent inhibitory activity towards IL-6 production in lipopolysaccharide (LPS)-induced THP-1 cell line, with an IC50 value of 2.02 μM, and NO production in LPS-activated RAW264.7 macrophages, with an IC50 value of 1.11 μM.

Aspersecosteroids A and B, Two 11(9 → 10)- abeo-5,10-Secosteroids with a Dioxatetraheterocyclic Ring System from Aspergillus flocculosus 16D-1.

Two 11(9 → 10)- abeo-5,10-secosteroids possessing an unprecedented dioxatetraheterocyclic ring system, aspersecosteroids A (1) and B (2), and a new ergosteroid, asperflosterol (3), were isolated from the sponge-derived fungus Aspergillus flocculosus 16D-1. Their structures were determined by spectroscopic analysis, X-ray diffraction, and computational methods. Compounds 1-3 demonstrated inhibitory effects on key pro-inflammatory cytokine production in THP-1 cells. A biogenetic pathway with oxidative cleavage, Wagner-Meerwein rearrangement, and sequential acetalization as key steps is proposed for 1 and 2.

Preussins with Inhibition of IL-6 Expression from Aspergillus flocculosus 16D-1, a Fungus Isolated from the Marine Sponge Phakellia fusca.

New pyrrolidine alkaloids, preussins C-I (1-7) and (11 R)/(11 S)-preussins J and K (8 and 9), were isolated from the sponge-derived fungus Aspergillus flocculosus 16D-1. The structures and configurations of these preussins were elucidated by detailed spectroscopic analysis, modified Mosher's method, and comparisons with literature data. These compounds showed strong to moderate inhibitory activity toward IL-6 production in lipopolysaccharide-induced THP-1 cells with IC50 values ranging from 0.11 to 22 μM, but were inactive against normal tumor cell lines and fungi.

Inhibitors of RANKL-induced osteoclast differentiation from the Marine Fungus Aspergillus flocculosus isolated from a Sponge Stylissa sp.

Inhibitors of RANKL-induced osteoclast differentiation from the Marine Fungus Aspergillus flocculosus isolated from a Sponge Stylissa sp.

Suppression of RANKL-Induced Osteoclastogenesis by the Metabolites from the Marine Fungus Aspergillus flocculosus Isolated from a Sponge Stylissa sp.

A new α-pyrone merosesquiterpenoid possessing an angular tetracyclic carbon skeleton, ochraceopone F (1), and four known secondary metabolites, aspertetranone D (2), cycloechinulin (3), wasabidienone E (4), and mactanamide (5), were isolated from the marine fungus Aspergillus flocculosus derived from a sponge Stylissa sp. collected in Vietnam. The structures of Compounds 1–5 were elucidated by analysis of 1D and 2D NMR spectra and MS data. All the isolated compounds were evaluated for anti-proliferation activity and their suppression effects on receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclast differentiation using tartate-resisant acid phosphatase (TRAP). Compounds 1–5 had no anti-proliferative effect on human cancer cell lines up to 30 μg/mL. Among these compounds, aspertetranone D (2) and wasabidienone E (4) exhibited weak osteoclast differentiation inhibitory activity at 10 μg/mL. However, mactanamide (5) showed a potent suppression effect of osteoclast differentiation without any evidence of cytotoxicity.

Antimicrobial ergosteroids and pyrrole derivatives from halotolerant Aspergillus flocculosus PT05-1 cultured in a hypersaline medium

In order to obtain more structurally novel and bioactive lead compounds for subsequent drug discovery, we have shifted the focus of our study from traditional microbial resources to 'extremophiles'. In this study, a halotolerant fungus Aspergillus flocculosus PT05-1 was isolated from the sediment of Putian saltern of Fujian Province of China in a hypersaline medium. Two new compounds, (22R,23S)-epoxy-3β,11α,14β,16β-tetrahydroxyergosta-5,7-dien-12-one (1) and 6-(1H-pyrrol-2-yl)hexa-1,3,5-trienyl-4-methoxy-2H-pyran-2-one (5) (existed as a pair of epimers with the configuration of 1E,3Z,5E and 1E,3E,5E separately), along with nine known compounds were isolated and identified from the fermentation broth of A. flocculosus PT05-1 grown at a 10% saline medium. New ergosteroid 1 together with 7-nor-ergosterolide (2) and 3β-hydroxyergosta-8,24(28)-dien-7-one (3) showed cytotoxicity against HL-60 and BEL-7402 cells with IC50 values of 12-18μM, and antimicrobial activity against Enterobacter aerogenes, Pseudomonas aeruginosa, and Candida albicans with MIC values of 1.6-15μM, respectively. New compound 5 exhibited antibacterial effect on E. aerogenes with MIC value of 3.7μM. This study also showed great prospects in developing medicinal resources from extremophiles.