Bioactive Agents from Natural Sources: Trends in Discovery and Application - Advances in Biochemical Engineering Biotechnology - page 122

Fig.8 (continued)
4.1.3
Future Potential
The future potential of the physico-chemical and the chemical screening
approach lies in the possibility ofaccessing the outstanding structural resources
from nature and to build up a collection of pure new and known natural pro-
ducts which can advantageously be used for broad biological screening.Natural
compound collections ofsubstantial structural diversity contribute to improved
lead discovery,and efficiently support synthetic libraries (e.g.from classical or
combinatorial synthesis). Often, it is better to run a biological screening with
pure compounds from natural sources rather than with crude extracts.In order
to extend the opportunities arising from testing pure compounds,in Germany a
collection of natural products and derivatives is being established under the
leadership of the HKI in Jena.The start up of the so called Natural Product Pool
has been funded by both German companies and the German Government
[194,195].
4.2
Approaches to Enlarge Structural Diversity from Nature
Structure modification programs of biologically active compounds (leads) are
an integral part ofdrug development.Among the many objectives ofthe deriva-
tization of lead structures are gain of information on structure/activity rela-
tionships, enhancement of intrinsic potency, providing oral applicability, in-
crease in bioavailability, elimination of unwanted side effects, and in case of
antibiotics, overriding resistance mechanisms. Such lead optimization pro-