Creation of New Local Anesthetics Based on Quinoline Derivatives and Related Heterocycles

Pain is a widely spread symptom and one of the most common causes making people seek medical attention. Though at present, different methods of pain control such as general narcosis, acupuncture, hypnosis, electroanaesthesia, homeopathy, etc., are known, nothing is better for safety and reliability than local anaesthesia. More often it is an effective alternative to general narcosis and promotes decreasing and even eliminating the use of narcotic analgesics in surgery. Dentists, dermatologists and other medical professionals apply it in their work. Unfortunately, an "ideal" local anesthetic has not been created yet, and all current medicines of the given pharmacological group have some drawbacks. The most serious disadvantages are high neuroand cardiotoxicity, as well as tendency to cause allergy. Thus, the search for new, more effective and safe local anesthetics is ongoing and scientists all over the world continue to work on this problem. Quinolines are the interesting compounds for research in this area. Numerous derivatives of this azaheterocycle are widely distributed in nature. Some of them are well-known to man and used for curative purposes from ancient times. For example, alkaloids cinchonine (1a, R = 〉) and quinine (1b, R = 《〈е, Figure 1) with antimalarial properties are isolated from Cinchona L. The utility of the majority of other natural quinolines prospects are to be determined. However, recently there has been a noticeable progress toward a solution of this problem. Natural compounds themselves more often attract the attention of scientists working in different fields of science and engineering. The stimulating motive for their research is the widely spread conviction that the living nature does nothing without purpose and everything it synthesizes is important at all events for life and, therefore, for man (Bochkov & Smith, 1987). This conviction finds the experimental confirmation constantly, as a result, at present the spectrum of biological properties of natural quinolines has expanded significantly (Kartsev, 2007).