Botryane, noreudesmane and abietane terpenoids from the ascomycete Hypoxylon rickii

Abstract

In the course of our screening for new bioactive natural products, a culture of Hypoxylon rickii, a xylariaceous ascomycete collected from the Caribbean island Martinique, was identified as extraordinary prolific producer of secondary metabolites. Ten metabolites of terpenoid origin were isolated from submerged cultures of this species by preparative HPLC. Their structures were elucidated using spectral techniques including 2D NMR and HRESIMS. Three of the compounds were elucidated as new botryanes (1-3) along with three known ones, i.e. (3aS)-3a,5,5,8-tetramethyl-3,3a,4,5-tetrahydro-1H-cyclopenta[de]isochromen-1-one (4), (3aS,8R)-3a,5,5,8-tetramethyl-3,3a,4,5,7,8-hexahydro-1H-cyclopenta[de]isochromen-1-one (5) and botryenanol (6). Further three new sesquiterpenoids featured a 14-noreudesmane-type skeleton and were named hypoxylan A-C (7-9); the diterpenoid rickitin A (10) contains an abietane-type backbone. Compounds 1, 2, 3, 7, and 10 showed cytotoxic effects against murine cells.

Rickenyls A–E, antioxidative terphenyls from the fungus Hypoxylon rickii (Xylariaceae, Ascomycota)

“…1) were isolated from the acetone extract of the mycelium derived from a fermentation of H. rickii in 70 l scale (Kuhnert et al, 2015b), using RP-MPLC followed by RP-HPLC.…”

“…Large scale fermentation was conducted in a 70 l bio reactor using HLX medium (3.0% sucrose, 1.0% casamino acids, 0.1% K 2 HPO 4 , 0.1% yeast extract, 0.05% MgSO 4 Â 7H 2 O, 0.05% KCl, 0.001% FeSO 4 Â 7H 2 O) as described by Kuhnert et al (2015b).…”

“…Previously, we already reported ten terpenoids with different scaffolds from a large scale fermentation of the strain (Kuhnert et al, 2015b). Moreover, we reported the occurrence of silphiperfolene-type secondary metabolites, a class http://dx.doi.org/10.1016/j.phytochem.2015.08.004 0031-9422/Ó 2015 Elsevier Ltd. All rights reserved.…”

ISOLATION OF TWO BOTRYANES FROM Hypoxylon rickii AND IDENTIFICATION OF THE ENCODING GENES

“…The isolated compounds include the following: (3aS)-3a,5,5,8-tetramethyl-3,3a,4 [11]. The structure of compound 1 was further confirmed using 2D NMR experiments including HMBC.…”

Sporochartines A–E, A New Family of Natural Products from the Marine Fungus Hypoxylon monticulosum Isolated from a Sphaerocladina Sponge

“…Among the 16 genera reported, Hypoxylon with 14 species is largely distributed in various marine and terrestrial habitats, and producing a large variety of bioactive compounds among which cohaerins (Quang et al, 2005a;Surup et al, 2013), daldinins and daldinones (Quang et al, 2004;Gu et al, 2007), cytochalasin (Espada et al, 1997), fragiformin , mitorubrinols (Quang et al, 2005b), hypoxylonols (Fukai et al, 2012), hypoxylans (Kuhnert et al, 2015a), hypoxyvermelhotins , rickenyls (Kuhnert et al, 2015b), rutilins (Quang et al, 2005b), carneic acids , hymatoxins (Bodo et al, 1987;Borgschulte et al, 1991), malettinins (Angawi et al, 2005), hypoxysordarin (Daferner et al, 1999), lenormandins (Kuhnert et al, 2015c), nodulisporic acids (Bills et al, 2012), schweinitzin A (Linh et al, 2014), truncatones (Sudarman et al, 2016), macrocyclic polyesters 15G256 family (Schlingmann et al, 2002), and sporothriolide (Krohn et al, 1994;Surup et al, 2014;Cao et al, 2016).…”