Secondary Metabolites and Bioactivities of Aspergillus ochraceopetaliformis Isolated from Anthurium brownii

Abstract

Five new polyketides, asperochrapyran ( 1 ) and asperochralactones A–D ( 2 – 5 ), along with 12 known polyketides ( 6 – 17 ), were obtained from the fungal strain Aspergillus ochraceopetaliformis . Structures of all isolates were elucidated by their spectroscopic parameters. The relative configurations of the new compounds were deduced by the data of coupling constants and NOESY spectra. The absolute configurations were determined by the comparison of experimental and calculated ECD spectra. Moreover, the plausible biosynthesis pathway of major isolates was proposed as well. Anti-inflammatory activity of compounds 5 and 7 – 17 were evaluated with human neutrophils in response to the stimulation of formyl-methionyl-leucyl phenylalanine (fMLP). Asperlactone ( 9 ), aspyrone ( 13 ), and (−)-(3 R )-mellein ( 14 ) exerted superoxide anion inhibition at 30 ± 9%, 29 ± 9%, and 26 ± 12%, respectively, at 10 μM. The capacities of asperlactone ( 9 ), aspilactonol B ( 10 ), penicillic acid ( 12 ), and (−)-(3 R )-mellein ( 14 ) in elastase release inhibition were revealed as 25 ± 4%, 38 ± 8%, 25 ± 5%, and 34 ± 9%, respectively, at 10 μM.

Polyketide Derivatives from the Endophytic Fungus Phaeosphaeria sp. LF5 Isolated from Huperzia serrata and Their Acetylcholinesterase Inhibitory Activities

“…Furanone and its derivatives have been shown to inhibit the formation of bacterial biofilms; interfere with bacterial population effects; and have analgesic, anti-inflammatory, anticancer, anticonvulsive, antibacterial, antifungal, antioxidation, and other activities. Most of the furanone compounds are synthesized by a single polyketone pathway, although chain fusion of furanone has also been reported in recent years [ 19 , 36 ]. In this study, compounds 4 and 9 possessed o-diol side chains.…”

“…Then, c undergoes ring-opening and oxidation to generate the intermediate d , which is dehydrated to produce compound 4 . Compound 2 is synthesized from d through an undefined pathway, then methylated to compound 3 and decarboxylated to compound 1 [ 19 , 36 ]. Compounds 8 – 11 are isocoumarin derivatives ( Scheme 2 ), whose biosynthesis by the polyketone synthesis pathway begins with acetyl-CoA.…”

“…They are classified into three structural types: linear (aspinonene), δ-lactones (aspinrone), and γ-lactones (isoaspinonene and aspilactonols) [ 17 ]. To date, it has been a challenging task to assign the absolute configurations of furanone derivatives due to the flexibility of their aliphatic sidechain in the partial polyketide unit [ 18 , 19 ]. Isocoumarins comprise a six-membered oxygen heterocycle (α-pyranone) with one benzene ring.…”

Three New Metabolites From the Marine-Derived Fungus Aspergillus sp. WHUF03110

“…In recent years, marine-derived fungi have attracted much attention from natural medicinal chemists, and many secondary metabolites possessing intriguing structures and various activities have been reported. 1 Aspergillus is a chemically brilliant fungal genus with immense potential to produce a wide range of unique secondary metabolites including polyketides, [2][3][4] alkaloids, 5-7 peptides 8,9 and terpenoids. 10,11 Some of these metabolites exhibit intriguing biological properties, including antimicrobial, 5,7,11 pro-angiogenesis, 6 and cytotoxic, 2,4,10 as well as enzyme-inhibiting activities.…”

Ochraceopyronide, a Rare α-Pyrone-C-lyxofuranoside from a Soil-Derived Fungus Aspergillus ochraceopetaliformis

“…A hexadepsipeptide and its hydrolyzed linear analog were isolated from a Korean marine sediment strain, with moderate/weak enzyme inhibition activities [ 19 ]. Polyketides asperochrapyran and asperochralactones A−D together with another 12 known polyketides were found produced by a strain isolated from plant leaves and examined for cytotoxic and anti-inflammatory properties [ 20 ].…”