title: Biocatalytic amidation of carboxylic acids and their antinemic activity.
abstract: A series of novel N-alkyl substituted amides, synthesized by enzyme catalysis, were evaluated against root-knot nematode, Meloidogyne incognita and found to have potential antinemic activity. The corresponding amides were prepared by the condensation of equimolar amounts of carboxylic acids with different alkyl amines in the presence of Candida antarctica lipase at 60-90 degrees C in 16-20 h. The reactions were carried out in a non - solvent system without the use of any activating agents. All the products were obtained in appreciable amounts and the yields for different compounds varied between 77.4-82.3%. The synthesized compounds were characterized using spectroscopy techniques namely Infra Red (IR) and Nuclear Magnetic Resonance (NMR) ((1)H and (13)C). Nematicidal activity of synthesized amides was evaluated against J(2)s of Meloidogyne incognita at 500, 250, 125 and 62.5 ppm concentrations after 24 h, 48 h and 72 h of exposure. Among all the tested compounds, N-propyl-butyramide, N-propyl-pentanamide and N-propyl-hexanamide were found to possess significant activity with LC(50) values of 67.46, 83.49 and 96.53 respectively. N-propyl-butyramide with LC(50) value of 67.46 ppm was found to be most active amide against J(2)s of Meloidogyne incognita. The bioactivity study showed that an increase in alkyl chain significantly decreased the activity of amides against root-knot nematode.
authors.affiliation: Division of Agricultural Chemicals, Indian Agricultural Research Institute, New Delhi, India.
authors.forename: Abinesh
authors.initials: A
authors.lastname: Bose
authors.forename: Najam Akhtar
authors.initials: NA
authors.lastname: Shakil
authors.lastname: Pankaj
authors.forename: Jitendra
authors.initials: J
authors.lastname: Kumar
authors.forename: Manish K
authors.initials: MK
authors.lastname: Singh
mesh_terms: D000577:Amides / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D000969:Antinematodal Agents / Q000737:chemistry / Q000494:pharmacology*; D002264:Carboxylic Acids / Q000737:chemistry / Q000494:pharmacology*; D002384:Catalysis; D004305:Dose-Response Relationship, Drug; D005656:Fungal Proteins; D007700:Kinetics; D008049:Lipase / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D019265:Spectroscopy, Near-Infrared; D014431:Tylenchoidea / Q000187:drug effects* / Q000254:growth & development
chemical_list: D000577:Amides; D000969:Antinematodal Agents; D002264:Carboxylic Acids; D005656:Fungal Proteins; D008049:Lipase; C431349:lipase B, Candida antarctica