Antifungal and antimycotoxigenic metabolites in Anacardiaceae species from northwest Argentina: isolation, identification and potential for control of Fusarium species

Abstract

Aims: The purpose of this research was to identify antifungal compounds from leaves of Schinus and Schinopsis species useful for the control of toxigenic Fusarium species responsible of ear rot diseases. Methods and Results: Leaves of Schinopsis (S. lorentzii and S. haenkeana) and Schinus (S. areira, S. gracilipes and S. fasciculatus) were sequentially extracted with dichloromethane, ethyl acetate and methanol. The antifungal activity of the fraction soluble in methanol of these extracts (fCH 2 Cl 2 , fAcEt and fMeOH, respectively) was determined by the broth microdilution method and the discdiffusion method. The minimum inhibitory dose (MID), the diameter of growth inhibition (DGI) and the minimum concentration for 50% inhibition of fungal growth (MIC 50 ) were calculated. The fCH 2 Cl 2 and fAcEt of the Schinopsis species had the lowest MID and MIC 50 values and the highest DGI. The antifungal compounds were identified as lupeol and a mix of phenolic lipids. The last one had the highest antifungal activity with MIC 50 31-28 lg g À1 and 165-150 lg g À1 on Fusarium graminearum and Fusarium verticillioides, respectively. The identified metabolites completely inhibited fumonisin and deoxynivalenol production at lower concentrations than ferulic acid, a natural antimycotoxigenic compound. Conclusions: It was proven that lupeol and phenolic lipids were inhibitors of both fungal growth and mycotoxin production of toxigenic Fusarium species. This fact is specially interesting in the control of the toxigenic Fusarium species because several commercial antifungals showed to stimulate mycotoxin biosynthesis at sublethal concentrations. Significance and Impact of the Study: Control of toxigenic Fusarium species requires compounds able to inhibit both fungal growth and mycotoxin production. Our results suggest that the use of lupeol as food preservative and the phenolic lipids as fungal growth inhibitors of F. verticillioides and F. graminearum did not imply an increase in mycotoxin accumulation.

Antifungal activity ofParastrephia quadrangularis(Meyen) Cabrera extracts againstFusarium verticillioides

“…Previous studies using plant extracts with antifungal activity they found that also has antimycotoxigenica activity (Aristimuño Ficoseco et al . ). In this regard, it would have been expected that extracts of P. quadrangularis present a similar effect.…”

“…The ground dry plant material was sequentially macerated in hexane (Hx), DCM, EtOAc and MeOH (100 ml each) at room temperature in total darkness for 24 h; were filtered, dried under reduced pressure at 40°C and weighed (Aristimuño Ficoseco et al . ; Babajide et al . ).…”

Allergens of the urushiol family promote mitochondrial dysfunction by inhibiting the electron transport at the level of cytochromes b and chemically modify cytochrome c1

“…The inhibitory effect of urushiols at the level of mitochondrial respiration may represent a critical defense system in plants belonging to the Anacardiaceae family to avoid herbivorous predators and pathogenic fungi [54,55]. It is noteworthy that Rodentia, being the order with the most mammalian species, including rats and mice, lacks CD1a and almost all group 2 lipid-presenting molecules [9,10], suggesting an advantageous characteristic for them, perhaps expanding their sources of food.…”

Antifungal activity of Euphorbia species against moulds responsible of cereal ear rots

“…Retention index of each identified compound was calculated in relation to n ‐alkanes (Aristimuño Ficoseco et al . 2014).…”