الفهرس 
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Abstract
Cancer and infectious diseases cause millions of deaths worldwide per year, and the
number of affected persons and deaths are increasing steadily. The development of new
chemotherapeutic agents for the treatment of cancer and microbial infections is still urgently
needed to help to ensure the availability of new drug candidates to feed the preclinical
pipeline. This will help to surmount current issues arising from the drawbacks of current
drugs such as low efficacy, significant side effects and resistance. In this context, plants are
still an important resource for the discovery of new drugs. Natural products have recently
drawn renewed interests and attentions as the seed of novel medicines. 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 thesis is to establish practical
synthetic route 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 minor alkaloid neocryptolepine 1 and major alkaloid
cryptolepine 2, were isolated from the roots of the West African climbing shrub Cryptolepis
sanguinolenta (Figure 1), a traditional herb used in folk medicine for the treatment of malaria.
Both of the two tetracyclic heteroaromatic compounds are linearly fused indoloquinolines and
exhibit a wide scope of biological activity. Therefore, we selected neocryptolepine 1 as the
lead compound for the development of a new drug because of its lower cytotoxic activity
compared to cryptolepine 2 towards the DNA intercalation, in addition natural product
alkaloids are known for their broad spectrum of pharmacological activity.