الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Cancer is one of the leading causes of death in the world. Though advances in cancer therapy and diagnosis have considerably improved life expectancy, the overall survival rate of patients still remains poor. Disseminated cancer at the time of diagnosis and acquisition of tumour resistance are two main reasons. The growing knowledge of the biochemical pathways involved in a disease process increases the possibility to develop new approaches to treat this disease. An extremely promising strategy for cancer prevention today is the chemotherapy, which is defined as the use of synthetic or natural agents (alone or combination) to block the development of cancer in humans. A major obstacle for the successful use of chemotherapy in cancer treatment is tumor cell resistant. Therefore, the need to find a safe and highly effective cure for cancer remains a major challenge for modern science. from these background, natural products offers novel concepts in structural diversity and molecular recognition that can be used in drug design.. In this context, natural products are still an important resource for the discovery of new drugs. However, availability of such natural products from nature tends to be severely limited. In order to develop novel medicines from natural products, sufficient amounts of compounds need to be provided for derivatization and biological testing. One of the goals of our research program is to establish practical synthetic routes for the natural products of medicinal importance. In addition, a variety of derivatives of the natural products will be synthesized for biological testing. Many naturally occurring compounds, including the natural product alkaloid neocryptolepine 1 and its regioisomercryptolepine 2, were isolated from the roots of the West African plants Cryptolepissanguinolenta (Figure 1). Both of the two tetracyclic heteroaromatic compounds are linearly fused indoloquinolines and exhibit a wide scope of biological activity.