Pharmacological, theoretical studies

Comprehensive reviews of the chemistry of sydnones (1) have been published elsewhere, and a general discussion of this subject is not included here. Recent work on the photochemistry (Section IX), physical and theoretical studies (Section XI), and pharmacological activity (Section XII) of sydnones (1) is included in later sections. 

Theoretical studies on thiepine-thianorcaradiene (benzene sulfide) valence isomerization have been of continuous interest. In addition, hypervalency of sulfur in thiepines has been theoretically studied. The interest in fused systems, such as dibenzo[/)/]thiepines, toward pharmacologically active compounds is growing. In the last decade, many reports on the synthesis, characterization, and utilization of enantiomerically pure dihydro- and tetrahydrothiepines and thiepanes have appeared. 

Table 1. Theoretical Studies on Systems of Pharmacological Interest.

In this section theoretical studies on cephalosporins are discussed that have had as their premise the available facts regarding the chemical steps that these molecules undergo when they exert their antibacterial activity. In fact, the B-lactam antibiotics are ideally suited for quantum pharmacology studies because a great deal is known about their biochemical mode of action and the target receptor sites. The mode of action is discussed in detail elsewhere in these volumes. Research on the interaction of p-lactams with bacterial cell walls is an area not lacking frequent comprehensive reviews of the many impressive advances (see, e.g.. 

Pharmacologic neuroprotection, which might be expected to prevent tissue necrosis or apoptosis until tissue reperfusion can be achieved with rt-PA, is a theoretically attractive adjunct to rt-PA treatment. Despite positive studies in animals, all evaluations of neuroprotective agents in humans have failed. Most recently, the promising initial results for intravenous NXY-059, a ffee-radical-trapping agent, were not replicated in a confirmatory phase III trial (unpublished data). 

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