%0 Journal Article %T A QSRR Modeling of Hazardous Psychoactive Designer Drugs Using GA-PlS and L-M ANN %A Hamzeh Karimi %A Hadi Noorizadeh %A Abbas Farmany %J ISRN Chromatography %D 2012 %R 10.5402/2012/838432 %X The hazardous psychoactive designer drugs are compounds in which part of the molecular structure of a stimulant or narcotic has been modified. A quantitative structure-retention relationship (QSRR) study based on a Levenberg-Marquardt artificial neural network (L-M ANN) was carried out for the prediction of the capacity factor (k¡ä) of hazardous psychoactive designer drugs that contain Tryptamine, Phenylethylamine and Piperazine. The genetic algorithm-partial least squares (GA-PLS) method was used as a variable selection tool. A PLS method was used to select the best descriptors and the selected descriptors were used as input neurons in neural network model. For choosing the best predictive model from among comparable models, square correlation coefficient (R2) for the whole set is suggested to be a good criterion. Finally, to improve the results, structure-retention relationships were followed by nonlinear approach using artificial neural networks and consequently better results were obtained. Also this demonstrates the advantages of L-M ANN. This is the first research on the QSRR of the designer drugs using the GA-PLS and L-M ANN. 1. Introduction Designer drugs (sometimes also referred to as club drugs) are a particular class of synthetic drugs most often associated with underground youth dance parties called raves, wherein participants listen to techno music and experiment with psychoactive substances. These drugs have been created by changing the molecular structure of other existing drugs, to create something new with similar pharmacological effects, hence, the name designer drug. They are plentiful, cheap, and dangerous. For example, the pharmaceutical drug amphetamine (which was originally created as an anesthetic) has been modified to be 80 to 1,000 times more potent than heroin. Prepared by underground, amateur chemists known as cookers, designer drugs can be injected, smoked, snorted, or ingested. These synthetic drugs can be easily obtained on the street or on the Internet. Once changed, they become known by a variety of street names, for example, XTC, Ecstasy, Adam, Lover¡¯s Speed, Special K, Fantasy, and Nature¡¯s Quaalude. Most have a rapid onset of affect (1 to 4 minutes) and a short duration of action (generally 30¨C90 minutes, and no more than a few hours). They are sold as tablets or capsules, and often produce feelings of stimulation and euphoria, a sense of well-being, and various sensory distortions. Higher doses can lead to paranoia, hallucinations, violent or otherwise irrational behavior, and fatal overdosing. Some designer drugs are %U http://www.hindawi.com/journals/isrn.chromatography/2012/838432/