Antioxidative and antifungal activity of azadirachtin derivative on infected tomato seed germination [electronic resource].

Includes reference.

Neem (Azadirachta indica) has been known for ages as an insecticidal plant and recently is classified as a therapeutic plant. In' this study, mere investigation has been done on the plant evaluation. Neem seeds extract has been fractionated into methanol, chloroform, butanol and hexane fractions. The fractions have been investigated for the antioxidative activity using the thiocyanate method under storage in dark at 40°C up to 25 days. The methanol fraction showed antioxidative activity (11%) extended to 25 days, comparing to 21.5% for vitamin E. A pro¬oxidative effect has been noticed from the butanol, chloroform and hexane fractions at the same period of time. The methanol fraction has the highest reducing power. It showed (0.55) absorbance value at 700 nm. This value has been followed by the hexane and chloroform fractions values. On the other hand, the butanol fraction showed no reducing power in the experiment. The potential of the neem methanol fraction might be due to the content of the phenols. The methanol fraction had the highest phenol content (0.147 g/100g as tannic acid or 5.78 g/100g as gallic acid) followed by the chloroform, butanol and hexane fractions, respectively. Further fractionation between methanol: distilled water showed that 30:70 v/v fraction, had the highest inhibition percentage against some pathogenic fungi. The inhibition (%) was 52.5 and 37.5 against Rhizoctonia solani and Fusarium solani, respectively. A potent compound has been separated from this fraction using TLC. The 300 ppm of this compound was the ideal concentration to inhibit R solani (70.3 %) and F. solani (57.9 %). The storage of this concentration in dark at 40°C was also followed in the pathogenic fungi inhibition up to 15 days. This concentration showed inhibition of 70, 50 % against R. solani and F. solani, respectively at the first day of storage. Between 7- 9 storage days, the inhibition % was decreased dramatically, correlated to the decrease in the antioxidative effect of the methanol fraction. In addition, the methanol fraction and the effective compound enhance the germination (%) of infected tomato seeds by R. solani or F. solani. The potent compound was identified using the MS technique. The compound was suggested to be; Trihydroxy-tetra acetyl-Azadirachtin. The hydroxyl groups, double bonds and the heterocyclic rings in the structure might be responsible for the variable potential of the compound.

Summary in Arabic.

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