Three green algae, collected from the Romanian Black Sea coast, are studied: Ulva lactuca, Enteromorpha intestinalis, and Cladophora vagabunda, which were collected from six different coastal areas. This paper aims to identify the bioactive compounds of these green algae and their beneficial properties, in order to use them as potential nutraceuticals using different analytical methods. Pharmacognostic, microbiological, and physico-chemical methods used for the analysis of algal materials revealed a rich and diverse array of biocompounds with nutritional value. In the case of green algae, a high percentage of sulphates, carbohydrates and dietary fibers were identified. Moisture, ash, total nitrogen, protein and lipid contents were determined. The contents of pigments, vitamins, and metals determined complement the nutritional qualities of the three seaweed species studied as future nutraceuticals. The content of flavonoid and phenolic compounds identified in the composition of seaweeds justifies their antioxidant and antimicrobial properties. The antioxidant capacity was tested by means of DPPH, reducing power, and TEAC methods, and the algae studied exhibit important antioxidant properties that can be used to enhance their potential as nutraceuticals. The studied algae show good antibacterial activity on both Gram (+) and Gram (−) bacteria, with slightly better activity on Gram (−) bacteria. Biocompounds from green algae from the Black Sea coast may represent an important source of marine nutraceuticals with medical and nutritional potential.

For human nutrition, algae are important organisms that can offer essential compounds and new bioactive substances with pharmaceutical and medicinal value. Macroalgae contain nutritional elements such as lipids, proteins, vitamins and minerals and they are used as food supplements because they are known to be high in mineral content. There are a lot of nutritionally compunds that can be identified in algae such as polysaccharides, polyphenols, diterpenes, sterols, carbohydrates, peptides, polyunsaturated fatty acids, pigments and dietary fibers. Nutraceuticals are confirmed to be used as medicines because they are a good protector against chronic diseases and they have physiological benefits. Algae bioactive compounds could be used as an anticoagulant, antioxidant, anti-inflammatory, antibacterial, antimicrobial, antifungal, anticancer, antiviral, antidiabetic, antiobesity, antihypertensive and hypercholesterolemic nutraceuticals. Although only some of the algae have been studied properly for their chemical composition and properties, they are a considerable biological resource with ability for use as a raw material. In this paper the compounds from red and brown algae from the Romanian seaside are evaluated as sources of biologically active ingredients with benefits in human health.