Cyclopentenones, Scaffolds for Organic Syntheses Produced by the Endophytic Fungus Mitosporic Dothideomycete sp. LRUB20

Abstract

Two new natural products, 2-hydroxymethyl-3-methylcyclopent-2-enone (1) (synthetically known) and cis-2-hydroxymethyl-3-methylcyclopentanone (2), and a known compound, asterric acid (3), were isolated from the endophytic fungus mitosporic Dothideomycete sp. LRUB20, which was isolated from the stem of the Thai medicinal plant Leea rubra. Compound 2 was separated and identified in the form of its 2,4-dinitrophenylhydrazone derivative (5). Compounds 1, 3, and hydrazone 5 exhibited mild antimycobacterial activity, both with MIC values of 200 microg/mL. Compounds 1, 3, and 4 were inactive (at 50 microg/mL) toward Vero, KB, NCI-H187, and BC cell lines. Hydrazone 5 showed only mild cytotoxicity against the Vero cell line with an IC(50) value of 21.7 microg/mL; however, it was inactive toward KB, NCI-H187, and BC cell lines. Endophytic fungi may be a source for the production of building blocks for organic syntheses.

Trichoderone, a novel cytotoxic cyclopentenone and cholesta-7, 22-diene-3β, 5α, 6β-triol, with new activities from the marine-derived fungus Trichoderma sp.

“…2). It should be noted that d C (180.1) of the C-3 double bond in 1 was significantly shifted downfield, similar to the carbonyl resonances d C (173.6) of the C-3 for 2-hydroxymethyl-3-methylcyclopent-2-enone [7]. The 1 H-1 H COSY spectrum showed correlations between H 2 -6 and H 3 -7, indicating the presence of an ethyl group.…”

“…Dihydroterrein and trichodenones were isolated from the marine-derived fungus Emericella variecolor and Trichoderma harzianum, respectively [20]. Some cyclopentenones were isolated from endophytic fungi, such as 2-hydroxymethyl-3-methylcyclopent-2-enone [7]. This is the first report on the isolation of compound 2 from Trichoderma sp., indicating that fungi may provide a novel source of this compound.…”

Two New Secondary Metabolites from the Endophytic Fungus Endomelanconiopsis endophytica

“…The broth was exhaustively extracted with ethyl acetate (EtOAc), and the concentrated EtOAc extract was further purified by various chromatographic methods to yield four compounds (1-4) ( Figure 1). Two new compounds, endomeketals A-B (1-2), were identified by spectroscopic analyses physicochemical properties, while a new natural product and a known compound were identified as 2,3-dimethylcyclopent-2-en-1-one (3) [16,17] and 2-hydroxymethyl-3-methylcyclopent-2-enone (4) [18] by comparison of their spectroscopic data with those in the literature. …”

“…By comparison of their spectroscopic data (Figures S15-S18) with those reported [16][17][18], the structures of compounds 3 and 4 were assigned as 2,3-dimethylcyclopent-2-en-1-one (3) and 2-hydroxymethyl-3-methylcyclopent-2-enone (4), respectively. Although compound 3 was previously reported as a synthetic compound, this is the first report of its isolation from a natural source.…”

Bioactive Cyclopentenone Derivatives from Marine Isolates of Fungi

“…2 For example, cyclopentenone prostaglandins A2, B2, C2, and J2 are naturally occurring representative biological cyclopentenone derivatives, 1 and a cyclopentenone derivative, methyl didehydrojasmonate, with a cyclopentenone pharmacophore introduced into the molecule, exhibits 29-fold greater antiproliferative activity against cancer cells. 3 Many bioactive cyclopentenone derivatives have been isolated from natural sources (e.g., marine-and terrestrial-derived fungi, [4][5][6][7][8][9][10][11][12][13][14][15][16] liverwort, 17 and plants 4 ) and exhibit diverse biological activities, including antimitotic, 4 antiinflammatory, 7 cyclooxygenase 2 (COX-2) inhibitory, 18 cytotoxic, [4][5][6]19 NF-kB inhibitory, 10,11 antimicrobial, 9,[12][13][14][15]17 antipigment, [12][13][14] and plant-growth-regulatory activities.…”