Naphthoquinone spiroketal with allelochemical activity from the newly discovered endophytic fungus Edenia gomezpompae.
Chemical investigation of the mycelium of Edenia gomezpompae, a newly discovered endophytic fungus isolated from the leaves of Callicarpa acuminata (Verbenaceae) collected from the ecological reserve El Eden, Quintana Roo, Mexico, resulted in the isolation of four naphthoquinone spiroketals, including three new compounds and palmarumycin CP2 (4). We elucidated the structures of the metabolites by extensive NMR spectroscopy studies, including DEPT, COSY, NOESY, HSQC, HMBC, and chiroptical methods. The trivial names proposed for these compounds are preussomerin EG1 (1), preussomerin EG2 (2) and preussomerin EG3 (3). In addition, the X-ray data for 4 were obtained. The bioactivity of the mycelial organic extracts and the pure compounds was tested against three endophytic fungi (Colletotrichum sp., Phomopsis sp., and Guignardia manguifera) isolated from the same plant species (C. acuminata, Verbenaceae) and against four economically important phytopathogenic microorganisms (two fungoid oomycetes, Phythophtora capsici and Phythophtora parasitica, and the fungi Fusarium oxysporum and Alternaria solani). Spiroketals 1-3 displayed significant growth inhibition against all the phytopathogens. IC50 values for the four phytopathogens were from 20 to 170 microg/ml. Palmarumycin CP2 (4) was not bioactive against any of the fungi tested. Compound 1 showed the strongest bioactivity. The acetylated derivatives of preussomerin EG1 (1), 1a and 1b, were obtained and their biological activity was tested on endophytes and phytopathogens. Preussomerin EG1 1, 1a and 1b exhibited significant bioactivity against all microorganisms tested with the exception of Alternaria solani. This is the first report of allelochemicals with antifungal activity from the newly discovered endophytic fungus E. gomezpompae.
Macías-Rubalcava
Martha L
ML
Instituto de Ecología, Departamento de Ecología Funcional, Universidad Nacional Autónoma de México, Apartado Postal 70-275, Ciudad Universitaria, 04510 Mexico DF, Mexico.
Hernández-Bautista
Blanca E
BE
Jiménez-Estrada
Manuel
M
González
María C
MC
Glenn
Anthony E
AE
Hanlin
Richard T
RT
Hernández-Ortega
Simón
S
Saucedo-García
Aurora
A
Muria-González
Jordi M
JM
Anaya
Ana Luisa
AL
D000935:Antifungal Agents / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D001203:Ascomycota / Q000737:chemistry* / Q000378:metabolism; D001681:Biological Assay; D018360:Crystallography, X-Ray; D017077:Culture Media, Conditioned / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D004852:Epoxy Compounds / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D005658:Fungi / Q000187:drug effects* / Q000254:growth & development; D006576:Heterocyclic Compounds, 4 or More Rings / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D008968:Molecular Conformation; D009281:Naphthalenes / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D010935:Plant Diseases / Q000382:microbiology; D018515:Plant Leaves / Q000382:microbiology; D013141:Spiro Compounds / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D013237:Stereoisomerism; D029648:Verbenaceae / Q000382:microbiology
D000935:Antifungal Agents; D017077:Culture Media, Conditioned; D004852:Epoxy Compounds; D006576:Heterocyclic Compounds, 4 or More Rings; D009281:Naphthalenes; D013141:Spiro Compounds; C462859:palmarumycin CP2; C530526:preussomerin EG1; C530528:preussomerin EG2; C530527:preussomerin EG3