Auxins structure-activity relationships

Soskic, M., Klaic, B., Magnus, V. and Sabljic, A. (1995). Quantitative Structure-Activity Relationships for N-(Indol-3-Ylacetyl)Amino Acids Used as Sources of Auxin in Plant Tissue Culture. Plant Growth ReguL, 16,141-152. 

W. Brandt, W. Grundler, and Z. M. Wiss, Math-Naturwiss. R., 38(1), 47 (1989). Structure-Activity-Relationships in Auxins from Theoretical Investigations of Conformations and Electrostatic Potentials. Part 2. Benzoic Acids. 

Of the bicyclic acids, i-naphthaleneacetic acid (NAA, IX) is the best known structural analogue of indoleacetic acid, also resembling the natural auxin in many aspects of its actions. The fact that the isomeric 2-naphthalene-acetic acid (X) is very weakly active only, forms one of the most intriguing questions on structure-activity relationships, especially when compared with the inverse relations found with the naphthoxyacetic acids (c/. Section 4). 

Since his undergraduate years, his research career has focused on the structure-activity relationships of bioactive compounds, starting with the auxin-type plant-growth regulators and herbicides. In 1961, he joined Corwin Hansch at Pomona College in Claremont, California, as a Postdoctoral Research Fellow. From 1961 to 1963, he and Hansch developed a novel procedure to quantitatively analyze structure-activity relationships of agrochemicals and medicines (QSAR). QSAR is regarded as a forerunner to the development of a number of recent computer-aided... 

Through a comparison of the insecticidal and toxicological data, structure-activity theories were developed which provided a means for the synthesis of safer compounds. A similar approach was used in the 2,4-D area. All manner of substituted phenoxy and benzoic acids and their derivatives were prepared. As a result, much was learned about the structural relationships for the auxin type action. This analog synthesis procedure has often been called "me too chemistry". The patent literature abounds with examples of such a strategy tried on almost everything that has shown a modicum of biological activity. 

Since the recognition of the auxin action of phenoxy acids extensive research has been undertaken to elucidate the relationships between the biological activity and chemical structure of this group of compounds (Audus, 1953 Fawcett et al., 1956 Wain, 1958 Fawcett et al., 1959 1960 Melnikov, 1971 Wain, 1975). 

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