Seaweeds are an excellent source of natural bioactive compounds. The exploration of novel natural compounds from marine resources has gained interest lately which possesses greater pharmaceutical and nutritional values. Seaweed phenolic compounds, particularly phlorotannin, have been discovered to have a variety of biological implications. Phlorotannin is a polyphenol that is found majorly in brown seaweed and is made up of polymeric units of phloroglucinol. The structural configuration and degree of polymerization were shown to influence biological activity. Several in vitro studies demonstrated that the phlorotannin derivatives had substantial bioactivity and were moderately appraised in vivo. Antioxidant, anticancer, anti-inflammatory, anti-allergic, anti-diabetic, and anti-microbial effects have been discovered in phlorotannin compounds. Recently, they have been evaluated for exhibiting anti-viral capacity against various harmful viruses. The findings suggested that phlorotannin could be an effective anti-viral molecule that requires intense research. This review focuses on the advanced techniques and research based on the experiments on phlorotannin for their extraction and purification. The phlorotannin as a potential drug molecule has been described from extraction to application. With the advent of technology, it is now possible to isolate the target molecule efficiently in less time. To make phlorotannin a novel nutraceutical and pharmaceutical molecule with wide industrial uses, preclinical and clinical research is required to assess its efficacy, toxicity, bioavailability, and drug delivery mechanism.
Key words: Bioactivity, Drug molecule, Phaeophyceae, Phenolic compounds, Phlorotannin.