The immobilized biocatalyst (IMB) is a key component of biotransformation systems that are used to transform substrates to desired products. The impro- ment of biocatalyst properties has a direct influence on the overall effectiveness of the process based on the biotransformation. The basic catalytic characte- stics of biocatalyst that are followed include kinetic properties, pH optima, stability,and inhibition. The investigation of catalytic properties of immobilized enzymes is still a time consuming procedure and is not always simple. In the 1980s,a major effort was made to standardize the rules by which IMB is char- terized. The Working Party of EFB on immobilized biocatalysts has formul- ed principles of individual methods, among them the requirement of kinetic characterization [1]. It was recommended to use a packed-bed reactor,equipped with temperature control and with infinite flow circulation. The system should be equipped with a post-column unit to measure the time-dependence of the product or substrate concentration [2, 3], the most commonly used analytical methods being spectrophotometry, chemiluminiscence, automatic titration, bioluminiscence, chromatography, polarimetry, and biosensors based on the oxygen electrode. There are two main drawbacks to the application of these methods: 1. The need to vary the analytical principles, depending on the chemical and physical-chemical properties of analytes; 2. In some cases, mainly in the study of hydrolytic enzymes, the natural s- strate must be replaced by an artificial one,that is chromolytic,chromogenic, chemiluminiscent,bioluminiscent,or fluorescent.

The immobilized biocatalyst (IMB) is a key component of biotransformation systems that are used to transform substrates to desired products. The impro- ment of biocatalyst properties has a direct influence on the overall effectiveness of the process based on the biotransformation. The basic catalytic characte- stics of biocatalyst that are followed include kinetic properties, pH optima, stability,and inhibition. The investigation of catalytic properties of immobilized enzymes is still a time consuming procedure and is not always simple. In the 1980s,a major effort was made to standardize the rules by which IMB is char- terized. The Working Party of EFB on immobilized biocatalysts has formul- ed principles of individual methods, among them the requirement of kinetic characterization [1]. It was recommended to use a packed-bed reactor,equipped with temperature control and with infinite flow circulation. The system should be equipped with a post-column unit to measure the time-dependence of the product or substrate concentration [2, 3], the most commonly used analytical methods being spectrophotometry, chemiluminiscence, automatic titration, bioluminiscence, chromatography, polarimetry, and biosensors based on the oxygen electrode. There are two main drawbacks to the application of these methods: 1. The need to vary the analytical principles, depending on the chemical and physical-chemical properties of analytes; 2. In some cases, mainly in the study of hydrolytic enzymes, the natural s- strate must be replaced by an artificial one,that is chromolytic,chromogenic, chemiluminiscent,bioluminiscent,or fluorescent.

Drug discovery strategies for both pharmaceutical and agrochemical applications are at a stage of rapid development. More than 30 % of sales of drugs for human consumption worldwide are of plant origin. This unique book covers the present status and future potential of natural products in drug discovery. It provides the reader with recent information regarding the impact on drug discovery, development and strategies, technical and automation aspects, and methods based on biochemistry as well as molecular biology, highlighting compounds from natural sources. Special emphasis is placed on the various strategies to gain access to natural compounds and combinatorial approaches by making use of both synthetic and biological methods. Because the renewed interest in the use of natural sources in drug discovery is an important supplement to combinatorial and parallel synthesis approaches, this book is timely and will have a great scientific impact.