Isolation and Characterization of Bioactive Compounds from Marine Algae

Eleni Madelou^*
*Correspondence: Eleni Madelou, Department of Pharmacognosy and Natural Products, Harokopio University of Athens, GR-17676 Athens, Greece, Email:

Keywords

Marine algae • Bioactive compounds • Pharmaceuticals

Introduction

Marine algae, encompassing a wide array of photosynthetic organisms such as seaweeds and phytoplankton, play an essential role in marine ecosystems and hold significant potential for human use. Their importance can be categorized into ecological, economic and health-related aspects. Marine algae are primary producers in the ocean's food web, conducting photosynthesis and converting carbon dioxide into organic matter. This process forms the basis of the marine food chain, supporting a diverse range of marine life from small invertebrates to large marine mammals. Marine algae contribute substantially to global oxygen production. It is estimated that phytoplankton, a type of microalgae, produce about 50% of the world's oxygen through photosynthesis. Algae play a crucial role in the global carbon cycle [1,2]. They absorb carbon dioxide from the atmosphere and, through biological processes, transfer it to the deep ocean, where it can be stored for long periods. This process helps mitigate the effects of climate change by reducing atmospheric CO₂ levels.

Literature Review

Macroalgae, such as kelp and seaweeds, form complex underwater habitats that provide shelter and food for various marine organisms. These habitats are critical for the biodiversity and productivity of marine ecosystems. Marine algae are integral to aquaculture, serving as a primary food source for farmed fish and shellfish. They are also harvested directly for human consumption in many cultures, particularly in Asia. Algae are used in a variety of industrial applications, including the production of biofuels, bioplastics and fertilizers. Algae-based biofuels are considered a sustainable alternative to fossil fuels, offering a renewable source of energy with a lower carbon footprint. Algal extracts are used as biofertilizers and soil conditioners in agriculture. They enhance soil health, improve crop yields and reduce the need for chemical fertilizers.

Marine algae are rich in essential nutrients, including proteins, vitamins, minerals and omega-3 fatty acids. They are considered a superfood, providing significant health benefits such as improved cardiovascular health, enhanced immune function and reduced inflammation. Algae are a source of bioactive compounds with therapeutic properties. Compounds such as phycocyanins, fucoidans and alginates have shown promise in treating various health conditions, including cancer, viral infections and inflammatory diseases. Algal extracts are widely used in the cosmetics industry for their skin-beneficial properties [3,4]. They are incorporated into skincare products for their moisturizing, anti-aging and protective effects against environmental stressors.

The process begins with the collection of marine algae from coastal and offshore environments. After collection, algae are cleaned to remove debris and epiphytes, followed by drying (usually under shade or using a freezedryer) to preserve the bioactive compounds. This is the most common method, using solvents like methanol, ethanol, acetone, or hexane to extract different compounds based on their polarity. Sequential extraction with solvents of increasing polarity can help in fractionating the compounds. This method uses supercritical CO₂, which has the advantages of being non-toxic and leaving no solvent residues, making it suitable for food and pharmaceutical applications. Ultrasound-Assisted Extraction (UAE) and Microwave-Assisted Extraction (MAE) techniques enhance the extraction efficiency and reduce extraction time by using ultrasound waves or microwaves to disrupt cell walls and facilitate the release of bioactive compounds.

Discussion

After extraction, crude extracts often contain a complex mixture of compounds. Techniques such as High-Performance Liquid Chromatography (HPLC), Gas Chromatography (GC) and Thin Layer Chromatography (TLC) are used to separate and purify the compounds. HPLC, in particular, is widely used due to its high resolution and ability to handle complex mixtures. Solid- Phase Extraction (SPE) is method concentrates and purifies the compounds by passing the extract through a solid adsorbent material, which retains the compounds of interest. Once isolated, the bioactive compounds are characterized to determine their chemical structure and biological activity. Nuclear Magnetic Resonance (NMR) spectroscopy, Mass Spectrometry (MS) and Infrared (IR) spectroscopy are the primary tools used for structural elucidation. NMR provides detailed information on the molecular structure, MS gives the molecular weight and fragmentation pattern and IR identifies functional groups [5,6]. For compounds that can be crystallized, this method provides a precise three-dimensional structure.

Methods such as DPPH, ABTS and FRAP assays measure the compound’s ability to scavenge free radicals. These are assessed using microbial culture methods and cell-based assays to determine the inhibitory effects on pathogens. Cell viability assays, such as MTT and apoptosis assays, are used to evaluate the effects on cancer cell lines. Enzyme inhibition assays and cytokine production studies help in understanding the anti-inflammatory potential. The bioactive compounds isolated from marine algae have immense potential in various fields. In pharmaceuticals, they offer novel leads for drug development, particularly for diseases where current treatments are inadequate. In nutraceuticals, algae-derived compounds can enhance dietary supplements, providing health benefits beyond basic nutrition. The cosmetics industry also benefits from algae extracts, which are used in formulations for skin protection and anti-aging.

Conclusion

The isolation and characterization of bioactive compound from marine algae is a dynamic and promising field. Advances in extraction and analytical techniques continue to improve the efficiency and effectiveness of these processes. As research progresses, the full potential of marine algae as a source of novel bioactive compounds is likely to be realized, offering significant benefits for health, wellness and industry. Marine algae are indispensable to both marine ecosystems and human industries. Their ecological roles ensure the health and productivity of ocean habitats, while their economic and health benefits provide sustainable solutions for food, energy and medical needs. As research continues to uncover the vast potential of marine algae, their importance is likely to grow, offering innovative approaches to global challenges such as climate change, food security and sustainable development.

Acknowledgement

None.

Conflict of Interest

None.

References

1. Lever, James, Robert Brkljača, Gerald Kraft and Sylvia Urban. "Natural products of marine macroalgae from South Eastern Australia, with emphasis on the Port Phillip Bay and heads regions of Victoria."Mar Drugs 18 (2020): 142.

   Google Scholar, Crossref, Indexed at

2. Zhou, Quan, Kinya Hotta, Yaming Deng and Rui Yuan, et al. "Advances in biosynthesis of natural products from marine microorganisms."Microorganisms9 (2021): 2551.

   Google Scholar, Crossref, Indexed at

3. Wu, Lichuan, Ke Ye, Sheng Jiang and Guangbiao Zhou. "Marine power on cancer: Drugs, lead compounds, and mechanisms."Mar Drugs19 (2021): 488.

   Google Scholar, Crossref, Indexed at

4. Bibi, Fehmida, Muhammad Imran Naseer and Esam Ibraheem Azhar. "Assessing the diversity of bacterial communities from marine sponges and their bioactive compounds."Saudi J Biol Sci28 (2021): 2747-2754.

   Google Scholar, Crossref, Indexed at

5. Pratheepa, V. and Vitor Vasconcelos. "Microbial diversity associated with tetrodotoxin production in marine organisms."Environ Toxicol Pharmacol 36 (2013): 1046-1054.

   Google Scholar, Crossref, Indexed at

6. Egan, Suhelen, Tilmann Harder, Catherine Burke and Peter Steinberg, et al. "The seaweed holobiont: Understanding seaweed–bacteria interactions."FEMS Microbiol Rev 37 (2013): 462-476.

   Google Scholar, Crossref, Indexed at