Indian Journal of Horticulture
  • Year: 1956
  • Volume: 13
  • Issue: 3

The Relation of Chemical Structure to Biological Activity in Certain Organic Compounds*

  • Author:
  • J. P. Singh†, C. L. Hamner‡
  • Total Page Count: 32
  • Page Number: 109 to 140

†Indian Agricultural Research Institute, New Delhi-12.

‡Michigan State University, East Lansing, U. S. A.

*A part of thesis submitted to the School of advanced graduate Studies, Michigan State University, East Lansing, U. S. A., in partial fulfilment of the requirement for the degree of Doctor of Philosophy-1956.

Abstract

Aromatic organic compounds containing an hydroxy! group or an acid group or both, other substituents and heterocycle nitrogen were investigated for their activities upon cucumber roots. A number of metal chelating compounds were also tested for their activities.

1. Compounds that most effectively stimulated root growth of cucumber seedlings grown in petri dishes were: 1.hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 4,4’-methylenebis-3-hydroxy-2-naphthoic acid and its disodium salt, 1-naphthol, 2, 4-dichloro-l-naphthol, 4, chloro-1-hydroxy-2-naphthoic acid. Slight response upon root elongation was observed with 2-naphthol, 8-quinolinol, benzoic acid, and l-hydroxy-2-naphthalene sulfonic acid (sodium salt).

2. Compounds, 1-naphthoic and 6-quinolinecarboxylic acids inhibited root growth of cucumber seedlings in a characteristic manner similar to the response of naphthaleneacetic acid on cucumber roots. Other active root inhibiting compounds were quinaldinic, 2-picolinic, 2-naphthoic acids, and 1-hydroxy-2-acetonaphthone.

3. No additive response upon cucumber root elongation occured when urea and KH2PO4 were simultaneously applied with 4,4’-methylenebis-3-hydroxy-2-naphthoic acid in petri dishes.

4. Metal chelate compounds found to stimulate cucumber root growth significantly at the 25 ppm dilution were: resorcinol benzotriazol, 2,2’-biquinoline, diethyldithiocarbamic acid, 2,4-dihydroxy-acetophenone and mercaptoacetic acid. Slight effect was observed with I-amino-4-hydroxy-anthraquinone, thiazole yellow, and furil dioxime compounds in petri dishes.

5. Among the metal chelate compounds tested that strongly inhibited cucumber root growth were: phenyl-y-thiohydrantoic acid, phenylglyoxal aldoxime and 2,2,4,4,0,6-hexanitrodiphenylamine. Somewhat less inhibition was found with l,5-(p-dimethylaminebenzylidene) and 2, 3-butanedione oximethiosemi-carbazone.

8. Other metal chelating and other organic compounds under investigation had no marked effect on cucumber root growth. Somewhat toxic effect was noticed at higher concentrations.