investigations and the mechanisms of action of natural products as agents for antidiabetic treatment. To summarize, natural products, particularly those derived from plants, are significant reservoirs of chemical compounds with diverse structures that may provide a therapeutic option for managing type 2 diabetes through various mechanisms.

In recent years, marine environments have emerged as promising sources of bioactive compounds with potent anticancer properties. Marine organisms, such as sponges, corals, mollusks, algae, and bacteria, have been found to produce a plethora of natural products exhibiting remarkable cytotoxicity against various cancer cell lines. This chapter high­lights the diversity and sources of marine-derived natural products with proven anticancer potential. It also emphasizes the various strategies employed in the isolation, identification, and characterization of bioactive compounds from marine sources. The chemical struc­tures, mechanisms of action, and preclinical and clinical studies of marine-derived natural products including alkaloids, terpenoids, peptides, polyketides, and steroids are described in detail. Furthermore, the limitations associated with the development of marine-derived natural products as anticancer drugs, including the need for sustainable collection methods, synthetic analogs for structure–activity relationship studies, and overcoming issues related to bioavailability and toxicity, are addressed. Strategies to enhance the production and supply of these compounds through biotechnology and synthetic biology approaches are also discussed. In conclusion, marine-derived natural products represent a valuable source of anticancer agents with diverse chemical structures and mechanisms of action. Continued research in this field, holds promise for the future discovery and development of marine­derived anticancer drugs.

In recent years, most of the lead compounds that have been shown to be useful in a wide range of pharmacological applications come from marine sources. It is noteworthy that

marine microorganisms are still the source of a significant number of essential bioactive compounds, although not many people are aware of this fact. There are microorganisms living in a broad variety of environments, ranging from the fine sand on a beach to the enormous ocean, which accounts for the majority of the earth’s biosphere. Microbes, especially those that reside in water, are able to survive in environments with high temperatures, high pressures, and incredible quantities of food. The therapeutic efficacy of biological materials derived from natural sources is evaluated with the use of high­throughput screening methods to facilitate the development of a method or product that is economically more viable. One of the greatest environments for bio-prospecting is marine habitat because it has a high number of microorganisms that have not yet been investigated. Microbes are very excellent at recognizing, responding, and adapting to their surroundings. To survive and thrive in their environment, they produce various secondary metabolites. Both biotechnology and medicine have made use of compounds that are produced under stress by organisms (Karthikeyan et al., 2022). There are still many bioactive molecules in the marine environment which are a promising source of nutraceuticals and functional foods. Many studies have used biotechnology to find and synthesize novel substances with the goal of expanding the variety of important chemicals already found in the ocean and making them more accessible. When compared to other biological reserves, ocean has received surprisingly less attention. It is the home to a diverse array of species, each of which has its own set of unique biological characteristics. It has been reported that algae and microalgae are an affluent source of bioactive chemicals that may be used in the preparation of nutritionally beneficial meals. Compounds derived from marine animals are particularly intriguing because of the fluctuations in salt, temperature, and light which occur as a natural aspect of marine atmosphere. Quantity and variety of marine functional components might increase by increasing the number of studies into locating and creating marine chemicals employing biotechnology. Marine bio-resources are responsible for the production of bioactive substances such as enzymes, peptides, proteins, phenolic compounds, polysaccharides, and fatty acids. These compounds have a relatively narrow use and a high level of potency. Proteins derived from marine sources include beneficial components of diets due to the myriad of fascinating and one-of-a-kind features that they possess. These properties include the capacity to produce gels and foams, as well as the ability to operate as an antibacterial agent. Phenolic compounds are an appealing candidate for usage in a variety of biotechnological contexts. One of the most promising sites to look for naturally occurring bioactive metabolites that are safe for the environment is in microalgae. Microalgae are living creatures that produce food by using light as an energy source. These are aquatic organisms that produce fatty acids, carotenoid pigments, and phenolic compounds (Avila and Angulo-Preckler, 2020).