be of significant importance in human welfare. The first part of the present chapter
primarily focuses on the different bioactive compounds isolated from algal biomass
to progress in the field of biomedical and biotechnology. The second part of the
chapter outlines the properties of the bioactive compounds along with their potential
application.
2 Microalgae-Derived Bioactive Compounds
At present, the interest in microalgae for industrial use is growing swiftly owing to
the presence of diverse and novel bioactive compounds, viz., antioxidants, fatty
acids, polysaccharides, proteins, vitamins, etc. Some of the important bioactive
compounds produced from microalgae are outlined below.
2.1 Polysaccharides
Polysaccharides are considered the most important product obtained from algae, as
per their economic value [7] with numerous reports on their structure and function
[7–9]. Algal polysaccharides can be extracted by several green techniques such as
microwave-assisted extraction (MAE) and enzyme-assisted extraction (EAE) [10–
12]. In recent years, these algal polysaccharides have been extensively studied due to
their biological activities like antiadhesive, antitumor, antitoxin, antioxidant, anticoagulant, anti-infection, and immunomodulatory effects. Certain polysaccharides
extracted from microalgae exhibits exceptional biomedical properties and thus can
have promising application in food, medicine, nutraceuticals, and cosmeceuticals.
For example, carrageenan, agar, and alginate are some of the commonly used algal
polysaccharides in food and pharmaceutical industries [13]. Some other polysaccharides like ulvans from Chlorophyta, carrageenans, porphyran from Rhodophyta
and fucans, and laminarin from Phaeophyta activate and enhance the defense
response against pathogens in plants [14]. Moreover, these algal polysaccharides
can directly or indirectly induce several signaling pathways, leading to the activation
of the immune system. For example, enhanced phagocytosis was observed by a
polysaccharide extracted from Porphyra haitanensis in RAW264.7 [15]. Algal polysaccharides also have remarkable antitumor activity both in vitro and in vivo which
is ascribed to the activation of cell-mediated immune responses [16]. For example,
polysaccharides isolated from Sargassum fusiforme were found to notably arrest the
growth of human HepG2 cell-transplanted tumor in nude mice [17]. Polysaccharide
galactan sulfate isolated from Agardhiella tenera was found effective against HIV-1
and HIV -2 [18]. Sulfated polysaccharides and xylogalacto fucan extracted from
Sphacelaria indica showed antiviral activity against herpes simplex viruses
[19]. Polysaccharides from algae possess antioxidative potential and, hence, can
be utilized in protecting the body from oxidative damage like a polysaccharide from
164
S. Sinha et al.
primarily focuses on the different bioactive compounds isolated from algal biomass
to progress in the field of biomedical and biotechnology. The second part of the
chapter outlines the properties of the bioactive compounds along with their potential
application.
2 Microalgae-Derived Bioactive Compounds
At present, the interest in microalgae for industrial use is growing swiftly owing to
the presence of diverse and novel bioactive compounds, viz., antioxidants, fatty
acids, polysaccharides, proteins, vitamins, etc. Some of the important bioactive
compounds produced from microalgae are outlined below.
2.1 Polysaccharides
Polysaccharides are considered the most important product obtained from algae, as
per their economic value [7] with numerous reports on their structure and function
[7–9]. Algal polysaccharides can be extracted by several green techniques such as
microwave-assisted extraction (MAE) and enzyme-assisted extraction (EAE) [10–
12]. In recent years, these algal polysaccharides have been extensively studied due to
their biological activities like antiadhesive, antitumor, antitoxin, antioxidant, anticoagulant, anti-infection, and immunomodulatory effects. Certain polysaccharides
extracted from microalgae exhibits exceptional biomedical properties and thus can
have promising application in food, medicine, nutraceuticals, and cosmeceuticals.
For example, carrageenan, agar, and alginate are some of the commonly used algal
polysaccharides in food and pharmaceutical industries [13]. Some other polysaccharides like ulvans from Chlorophyta, carrageenans, porphyran from Rhodophyta
and fucans, and laminarin from Phaeophyta activate and enhance the defense
response against pathogens in plants [14]. Moreover, these algal polysaccharides
can directly or indirectly induce several signaling pathways, leading to the activation
of the immune system. For example, enhanced phagocytosis was observed by a
polysaccharide extracted from Porphyra haitanensis in RAW264.7 [15]. Algal polysaccharides also have remarkable antitumor activity both in vitro and in vivo which
is ascribed to the activation of cell-mediated immune responses [16]. For example,
polysaccharides isolated from Sargassum fusiforme were found to notably arrest the
growth of human HepG2 cell-transplanted tumor in nude mice [17]. Polysaccharide
galactan sulfate isolated from Agardhiella tenera was found effective against HIV-1
and HIV -2 [18]. Sulfated polysaccharides and xylogalacto fucan extracted from
Sphacelaria indica showed antiviral activity against herpes simplex viruses
[19]. Polysaccharides from algae possess antioxidative potential and, hence, can
be utilized in protecting the body from oxidative damage like a polysaccharide from
164
S. Sinha et al.