MANNICH BASES OF 7-HYDROXY-4 -METHYL AND 4, 6, 7-TRIMETHYL COUMARINS AS POTENTIAL FUNGICIDES FOR ASPERGILLUS FLAVUS AND PYRRICULARIA ORZAE

Coumarin and its derivatives are widely used as scaffolds in synthesizing new heterocyclic systems. Numerous approaches especially involving nano-particle catalysts, have been developed to get new bioactive coumarin derivatives endowed with pharmacological and biological activities. The present work describes the reactivity and the new strategies for the synthesis of coumarin and its derivatives reported in the literature and their biological properties. Coumarins possess a number of biological activities like Anticoagulant, Antimicrobial, Anti-inflammatory, Analgesic, Antioxidant, Anticancer, Antiviral, Anti-malarial etc. Coumarin belongs to a group as benzopyrones, which consists of a benzene ring joined to a pyrone nucleus ¹². Coumarins (2H-1-benzopyran-2-ones) are important oxygen-containing fused heterocycles used in drugs and dyes. A number of coumarin derivatives have been reported to have diverse biological activities like fungicidal^1-4, molluscicidal ², antihelminthic ^{5, 6} and CNS ⁷ stimulants. Mannich Bases of some heterocyclic compounds are also reported Bioactive ^{8, 9}. In view of this Mannich bases of 7 – hydroxyl – 4 – methyl coumrin and 4, 6, 7– trimethyl coumaryl incorporating various DL–amino acids as a basic component were synthesized and evaluated for their fungitoxicity against A. flavus and P. oryzae.