Citrantifidiene and citrantifidiol: bioactive metabolites produced by Trichoderma citrinoviride with potential antifeedant activity toward aphids.
Two novel metabolites with potential antifeedant activity were isolated from cultures of the fungus Trichoderma citrinoviride strain ITEM 4484 grown in solid-state fermentation on sterile rice kernels. The producing strain was identified at species level by sequence analysis of the internal transcribed spacer regions ITS-1 and ITS-2 of the nuclear rDNA and a fragment of the translation elongation factor gene TEF-1alpha. Fractionation by column chromatography and TLC of the culture organic extract, followed by feeding preference tests on the aphid pest Schizaphis graminum (Rondani), allowed the purification of 5.8 and 8.9 mg/kg of culture of two bioactive metabolites, which were named citrantifidiene and citrantifidiol ( 1 and 2). Citrantifidiene and citrantifidiol, whose structures were determined by spectroscopic methods (NMR and MS) are a symmetrical disubstituted hexa-1,3-dienyl ester of acetic acid and a tetrasubstituted cyclohexane-1,3-diol, respectively. The pure metabolites influenced the feeding preference of S. graminum restraining individuals from feeding on wheat leaves dipped in 5% aqueous methanol solution containing 0.57 mg/mL of citrantifidiene or 0.91 mg/mL of citrantifidiol.
Evidente
Antonio
A
Dipartimento di Scienze del Suolo, della Pianta, dell'Ambiente e delle Produzioni Animali, Università di Napoli Federico II, Via Università 100, 80055 Portici, Italy. evidente@unina.it
Ricciardiello
Gaetano
G
Andolfi
Anna
A
Sabatini
Maria Agnese
MA
Ganassi
Sonia
S
Altomare
Claudio
C
Favilla
Mara
M
Melck
Dominique
D
D000085:Acetates; D000818:Animals; D001042:Aphids / Q000502:physiology*; D003511:Cyclohexanols / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D004435:Eating / Q000187:drug effects; D004952:Esters / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D007306:Insecticides / Q000302:isolation & purification*; D009682:Magnetic Resonance Spectroscopy; D014242:Trichoderma / Q000378:metabolism*
D000085:Acetates; D003511:Cyclohexanols; D004952:Esters; D007306:Insecticides; C530285:citrantifidiene; C530286:citrantifidiol