Discriminant analysis and structure-activity relationships. 1. Naphthoquinones

Prakash, Gopalakrishnan; Hodnett, Ernest M.

doi:10.1021/jm00202a011

Cited by 36 publications

(9 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Other methods have also been developed and applied to the study of QSAR (102), including pattern recognition (199)(200)(201)(202)(203)(204)(205)(206), cluster analysis (207,208), and discriminant analysis (204,209,210,211). Pattern recognition refers to a collection of methods used to detect relationships (i.e., patterns) within a large number of observations which simultaneously depend on many variables.…”

Section: Methods In Qsarmentioning

confidence: 99%

Parameters and Methods in Quantitative Structure-Activity Relationships

Osman

Weinstein

Green

1979

ACS Symposium Series

View full text Add to dashboard Cite

In studies of quantitative structure activity relationships (QSAR), the relative potencies of a series of drugs are subjected to analysis with the hope that biological potency will be described by a mathematical equation. QSAR is an actuarial or statistical method in which only objective data are used with no intrusion of models or mechanistic hypotheses. The equation that is obtained not only accounts for the relative potencies of the compounds, but from it are deduced predictions of the potencies of untested compounds; if the equation is valid, the predictions are ineluctable. The method thus has the capacity of yielding new (structurally related) drugs with desired potency, perhaps drugs with enhanced selectivity or fewer side effects.Further, in the method that is most widely used, the equation contains a parameter(s) that reflects a property related to the structural characteristics of the molecules. Therefore, the equation has often been assumed to provide insight into mechanisms that determine the action of drugs. In fact, the parameters that account for the biological potency are usually not truly empirical, observed entities, but rather abstractions. These parameters are frequently reified, burdened with a concrete meaning they were not designed to bear, and in this process the true molecular mechanisms may become obfuscated. Further, to infer a mechanism from a correlation is to assume that the correlation implies a causal relationship between the dependent and independent variables, when in fact the two may be conjoint but not causally related. Causality can be inferred only if a testable mechanistic hypothesis is offered that relates the correlation parameters to the observed biological activity.The attempt to correlate biological activity with chemical structure in quantitative terms assumes that a functional dependence exists between the observed biological response and certain physicochemical properties of molecules. Without a mechanistic model one obtains it by an empirical correlation. A rational way to define such empirical relationships is within the extrathermodynamic approach (1). Although extrathermodynamic relationships 0-8412-0521-3/79/47-112-021$13.55/0

show abstract

Section: Methods In Qsarmentioning

confidence: 99%

Parameters and Methods in Quantitative Structure-Activity Relationships

Osman

Weinstein

Green

1979

ACS Symposium Series

View full text Add to dashboard Cite

show abstract

“…This data set was chosen because the best discriminant function which could be generated from the sum of the parameters π, MR, and π 2 for the two substituents was only able to classify correctly 22 of the 27 compounds [34]. The network architecture used for this analysis consisted of two input units, one for π and one for MR, a hidden layer and two output units, so that one unit could be activated (take Table 9.7 Structure, physicochemical properties, and activity category of napthoquinones (reproduced from ref.…”

Section: Data Analysis Using Annmentioning

confidence: 99%

Artificial Intelligence and Friends

Livingstone

2009

A Practical Guide to Scientific Data Analysis

View full text Add to dashboard Cite

“…The leaving group had been shown to influence the degree of tumour-inhibitory activity in this system, with the best leaving group, in general, giving the highest values of T/C (T/C represents the ratio of survival time of treated to control animals) [6,7,9,13,17]. Redox potentials were measured in several cases, mainly in protic medium, through electrochemical methods [8,12,13,17] or pulse radiolysis [16], but their role in the biological activity is still inconclusive.…”

Section: Introductionmentioning

confidence: 99%