A New Dihydrobenzofuran Derivative from the Endophytic Fungus Botryosphaeria mamane PSU-M76

Abstract

In the course of our ongoing search for antimicrobial substances from plants and endophytic fungi, the ethyl acetate extract from the culture broth of the endophytic fungus Botryosphaeria mamane PSU-M76 exhibited interesting antibacterial activity against Staphylococcus aureus ATCC 25923 (SA) and methicillin-resistant S. aureus SK1 (MRSA) with MIC values of 32 and 64 mg/ml, respectively. The endophytic fungus B. mamane PSU-M76 was isolated from the leaves of Garcinia mangostana. Chemical investigation of B. mamane has never been reported. Investigation of the extract of the culture filtrate led to the isolation of one new dihydrobenzofuran derivative, botryomaman (1), along with six known compounds, 2,4-dimethoxy-6-pentylphenol (2), 1) (R)-(Ϫ)-mellein (3), 2) primin (4), 3,4) cis-4-hydroxymellein (5), 5) trans-4-hydroxymellein (6), 5) and 4,5-dihydroxy-2-hexenoic acid (7). 6) Their structures were assigned by spectroscopic methods and comparison of the 1 Hand 13 C-NMR data with those reported in literature. All compounds were tested for antibacterial activity against both strains. Botryomaman (1) was obtained as a white solid, melting at 149.6-150.0°C with [a] D 29 ϩ22.2°(cϭ0.2, MeOH). The UV spectrum showed a maximum absorption band at l max 300 nm. The IR spectrum exhibited absorption bands at 3392 cm Ϫ1 for a hydroxyl group and 1684 cm Ϫ1 for a carbonyl group of an a,b unsaturated carboxylic acid. The HR-EI-MS showed the molecular formula C 18 H 24 O 5. The 1 H-NMR spectrum displayed typical signals of two transolefinic protons of the a,b unsaturated carboxylic acid (d

An In Planta -Expressed Polyketide Synthase Produces ( R )-Mellein in the Wheat Pathogen Parastagonospora nodorum

“…In addition, it has been observed that mellein slows the cell cycle, with the cell having an extended mitotic phase (68). Interestingly, the biological sources of (R)-mellein are overrepresented in fungal plant pathogens (39,53,54,57,65) and endophytes (51,52,58,59). Whether mellein plays a role in this plant-fungus interaction and why SN477 is strongly upregulated in planta are questions that warrant future investigation.…”

New Natural Product from Botryosphaeria australis, an Endophyte from Mangrove Avicennia marina

“…This genus has been reported as epiphytic fungus on mangrove Sonneratia apetalla (Xu et al, 2011), as an endophyte from cacao (Theobroma cacao L.) (Rubini et al, 2005) as well as an endosymbiont in sponge Tetra auratium (Wiese et al, 2011). The examples of isolated metabolites include Primin (Pongcharoen et al, 2007), 4-hydroxymellein (Venkatasubbaiah et al, 1991), and Lasiodiploin (Yang et al, 2006).…”

Identification of phytotoxins from Botryosphaeria obtusa, a pathogen of black dead arm disease of grapevine

“…R-(-)-mellein has been reported from B. obtusa (Venkatasubbaiah and Chilton 1990;Venkatasubbaiah et al 1991) and more recently from Botryosphaeria mamane (Pongcharoen et al 2007). Due to the CD data, the isolated metabolite was identified as R-(-)-mellein.…”