Foreword The cher y of marine natural products has s these must be volatile,their chemical structures are often simple and many are easy to synthesize.In contrast,in an aqueous environment communication between living organisms depends on solubility in water.As a consequence,the chemica compounds used in the communication can have complex structures and large ve comp city.there are ractive to s to the omplicated.What is ed by the given all these factors it is not sumprising that marine organisms are a wonderful source of biologically active natural products.It has taken half a century for this to be fully appreciated.In this time the means of collection have been developed so that marine diving.at least in shallow coastal waters.is relatively simple an ava nche of ne there if th often avai am re is comp erial for clinical ials Th: synthetic chemist e to the help of the clinician.Marine natural products The present hook by dr ds Bhakuni a distinguished exnert on natura osgas a description of the compounds and their biosynthesis.Of course,there can be no clinical discovery without prior and extensive biological testing so these Foreword The chemistry of marine natural products has grown enormously in the last fifty years. On land, communication between insects is largely by pheromones. Because these must be volatile, their chemical structures are often simple and many are easy to synthesize. In contrast, in an aqueous environment communication between living organisms depends on solubility in water. As a consequence, the chemical compounds used in the communication can have complex structures and large molecular weights as long as there is adequate solubility in water. Since all forms of life are subject to perpetual competition, it is not surprising that the organisms that live in the sea produce an enormous range of biological activity. Besides the compounds that repel predators by their toxicity, there are those which are attractive to make reproduction more probable. In addition, there is a complex food chain from the simplest organisms to the most complicated. What is edible and what is not is also determined by the secondary metabolites of the life process. Given all these factors it is not surprising that marine organisms are a wonderful source of biologically active natural products. It has taken half a century for this to be fully appreciated. In this time the means of collection have been developed so that marine diving, at least in shallow coastal waters, is relatively simple. Also, more sensitive biological tests are available and can be carried out on board ship. The result of all this is that there is an avalanche of new and biologically exciting marine natural products. However, there is one negative aspect to this work. It is that the compounds isolated are often available in minute amounts only. Therefore, if the structure is complex, it is an arduous, and often impossible, task to isolate enough of the natural material for clinical trials. This is where synthetic chemistry can come to the help of the clinician. Marine natural products are often wonderful challenges to synthetic chemists. The present book by Dr. D.S. Bhakuni, a distinguished expert on natural products chemistry, [and Dr. D.S. Rawat] will serve as an excellent introduction to the scientific methods involved in marine natural products chemistry. It includes a description of the compounds and their biosynthesis. Of course, there can be no clinical discovery without prior and extensive biological testing so these