In vitro Screening of Curcuma longa L and its Derivatives sa Antifungal Agents against Helminthosporrum oryzae and Fusarium solani

Curcuma longa (turmeric) based products namely curcumins I, II, III, alkyl ether derivatives so curcumin-1 and turmeric oil were evaluated for their antifungal activity against two phytophagous fungi Helminthosporium oryzae and Fusarium solani. The most effective turmeric oil exhibited IC₅₀ of 12.7 μg mL⁻¹ against H. oryzae and 19.73 μg mL⁻¹ against F. solanii. Curcumin-III with respecttve IC₅₅ of 18.9 μg mL⁻¹ and 49.3 μg mL⁻¹ was next in order followed by curcumin-II (IC₆₀ 65.5 and 74.4 μg mL⁻¹) and curcumin-I (IC₅₀ 80.2 and 135.9/μg mL¹). Alkylation of curcumin-I did not result in products with improved efficacy.