Bioactive Nitronaphthalenes from an Endophytic Fungus, Coniothyrium sp., and Their Chemical Synthesis

Abstract

Four natural nitro metabolites, 1-hydroxy-5-methoxy-2-nitronaphthalene (2), 1,5-dimethoxy-4-nitronaphthalene (3), 1-hydroxy-5-methoxy-2,4-dinitronaphthalene (4), and 1,5-dimethoxy-4,8-dinitronaphthalene (5), known from chemical synthesis but new as natural products, were isolated together with two known compounds, 1-hydroxy-5-methoxynaphthalene (1) and ergosterol (6) from an endophytic fungus, Coniothyrium sp. The structures of 1-6 were determined by spec-

Structural and Stereochemical Studies of Hydroxyanthraquinone Derivatives from the Endophytic Fungus Coniothyrium sp

“…Isolation and structural elucidation afforded a series of naphthalene derivatives, including palmarumycins, nitronaphthalenes, and α ‐methylene‐ γ ‐lactone derivatives belonging to the group of massarilactones . These metabolites demonstrated antifungal, antibacterial, and antialgal activities in bioassays in vitro. In addition, several benzofuranones and derivatives have also been isolated from the fungus, showing similar antimicrobial activities …”

Diversity and Ecological Significance of Fungal Endophyte Natural Products

“…26) have been isolated from the endophytic fungus Coniothyrium sp. originated from the shrub of Sideritis chamaedryfolia [149]. Some of them (102 and 103) displayed significant antifungal activities against the phytopathogen Microbotryum violaceum, while compound 104 was inactive.…”

Practical synthesis of polysubstituted naphthalene derivatives via HNTf2-catalyzed benzannulation reaction

“…The reaction was stirred overnight at 80 o C. After completion and hydrolysis (H 2 O, 10 mL) the reaction mixture was transferred to a separating funnel. The aqueous phase was extracted with ethyl acetate (3 x 15 mL) and the combined organic extracts washed by water (4 x 40 mL) and brine (40 mL) before being dried over MgSO 4 . After filtration and evaporation of the solvents under reduced pressure, the crude material was purified by flash column chromatography on silica gel using cyclohexane as eluent to afford the desired naphthalene 10 as a white solid (33.7 …”

“…[1][2][3][4][5][6][7][8][9] Additionally, this particular aromatic structure can be found in numerous optical and electronic materials [10][11][12] and constitutes the backbone of many chiral ligands. 13 Nafacillin, 14 suramin, 15,16 which play a vital role in the control of microbial infection, are typical examples of drugs that present a naphthalene moiety ( Figure 1).…”

“…17,18 Construction of the second aromatic ring of the naphthalene core via a formal [4+2] process under various catalytic conditions is definitely one of the most direct and efficient methods. In particular, TiCl 4 or FeCl 3 in stoichiometric quantities as well as catalytic GaCl 3 or AuCl 3 /AgSbF 6 systems were found to promote the benzannulation reaction of arylacetaldehydes with alkynes. [29][30][31][32] Boron trifluoride etherate complex was also described as an appropriate catalyst for this transformation, in the specific case of terminal arylacetylenes.…”