Anti-influenza Virus Polyketides from the Acid-Tolerant Fungus Penicillium purpurogenum JS03-21

Abstract

Fractionation of the ethyl acetate extract of an acid-tolerant fungus, Penicillium purpurogenum JS03-21, resulted in the isolation of six new compounds, purpurquinones A-C (1-3), purpuresters A and B (4 and 5), and 2,6,7-trihydroxy-3-methylnaphthalene-1,4-dione (6), together with three known compounds, TAN-931 (7), (-)-mitorubrin (8), and orsellinic acid. The structures of 1-6 were elucidated primarily by NMR experiments. The absolute configurations of 1-4 were assigned on the basis of CD and NOESY data. Compounds 2-4 and 7 exhibited significant antiviral activity against H1N1, with IC50 values of 61.3, 64.0, 85.3, and 58.6 μM, respectively.

Talarolutins A–D: Meroterpenoids from an endophytic fungal isolate of Talaromyces minioluteus

“…Compounds 1, 2 , and 5 were further purified using prep RP HPLC [Kinetex-C 18 column, 21.2 mL/min] affording pure talarolutin A [ 1 , 1.7 mg, t R = 11.5 min; isocratic CH 3 CN:H 2 O (containing 0.1% HCOOH), 35:65 v/v], talarolutin B [ 2 , 6.9 mg, t R = 12.5 min; isocratic CH 3 CN:H 2 O (containing 0.1% HCOOH) 35:65 v/v], and purpurquinone A [ 5 , 1.2 mg, t R = 12.5 min; isocratic CH 3 CN:H 2 O (containing 0.1% HCOOH) 40:60 v/v]. The HRMS and 1H NMR data for 5 were fully consistent with those reported in literature (Wang et al, 2011). To achieve ≥ 95% pure sample of 2 , an additional purification step employing semi-preparative RP HPLC [YMC-C 18 column, isocratic CH 3 CN:H 2 O (containing 0.1% HCOOH), 40:60 v/v; λ = 210 and 254 nm; 3 mL/min] was carried out to yield pure talarolutin B ( 2 , 5.7 mg, t R = 29.0 min).…”

“…Due to low sample amounts, compounds 1 and 5 were not evaluated for any biological activity in various assays. Compound 5 was originally isolated from Penicillium purpurogenum and tested for bioactivity against influenza A virus (H1N1) but was found to be inactive (Wang et al, 2011). …”

“…In continuation of these investigations in search of new and/or biologically active natural products, an endophytic fungal isolate of Talaromyces minioluteus (G413), which was isolated from the leaves of milk thistle, was subjected to natural products chemistry techniques to yield four new meroterpenoids (Fig. 1), named here as talarolutins A–D ( 1–4 ), and one known compound, purpurquinone A ( 5 ) (Wang et al, 2011). Structurally diverse meroterpenoids with antimicrobial, antiviral, antitumor, immunomodulatory, and phytotoxic effects have been reported previously from various fungal sources (Geris and Simpson, 2009).…”

Antifungal and antiviral products of marine organisms

“…A variety of viruses including herpes simplex virus, fish nodavirus, fish nodavirus, influenza virus A and B, respiratory syndrome virus, porcine reproductive virus, tobacco mosaic virus, human metapneumovirus, human immunodeficiency virus, hepatitis C virus, herpes simplex virus, human cytomegalovirus, and white spot syndrome virus are produced by bacteria, fungi, algae, cnidarians, crustaceans, echinoderms, tunicates, and fish. Again, the mechanism of antiviral action has been examined only in some cases (Bandyopadhyay et al 2011; Kim et al 2012b; Wang et al 2011). Thus, it would be worthwhile to conduct detailed investigations on the mechanisms of antifungal and antiviral actions as well as the structure-function relationship of the marine biomolecules.…”

“…Purpurester A, purpurquinone B, and TAN-931 from the ethyl acetate extract of an acid-tolerant fungus, P. purpurogenum JS03-21, exerted anti-influenza A (anti-H1N1) activity with IC 50 values below 90 µM (Wang et al 2011). …”