Chemical Characterization of Selected Algae and Cyanobacteria from Bulgaria as Sources of Compounds with Antioxidant Activity

Abstract

The current research focused on algae from the waters of the Black Sea—Chaetomorpha linum, Ulva intestinalis, Ericaria crinita, and bioreactors—Chlorella spp. and Arthrospira platensis/cyanobacterium/. Pigment content, total phenolic content, and antioxidant capacity were investigated for their use as pharmaceutical, food, and cosmetic ingredients. E. crinita exhibited the highest antioxidant activity by ORAC and HORAC (463.3 µmol TE/g and 463.3 µmol GAE/g) and the highest total content of polyphenols and rutin of the investigated algae. Lower protein content was found in saltwater algae than in freshwater algae. For the first time, biologically active substances from the Bulgarian A. platensis and Chlorella spp., produced in a bioreactor, have been quantitatively identified. A. platensis contained rutin (141.25 mg/100 g), naringenin (42.17 mg/100 g), quercetin (26.74 mg/100 g), kaempferol, and quercetin-3-β-glycoside. Phenolic acids were isolated: neochlorogenic (172.27 mg/100 g) for lyophilized and 5783 mg/100 g for convection-dried A. platensis. It has been found that the protein content in A. platensis (convection dried) and Chlorella spp. (lyophilized) was nearly 54% higher than that of green algae U. intestinalis from Varna. The lyophilization process reduced the protein content of A. platensis samples by almost 20%. The high protein content of convection-dried A. platensis (43.4%) and lyophilized Chlorella spp. (43.7%) identified them as suitable emulsifiers in colloidal and emulsion systems.

Zygnema sp. as creator of copper oxide nanoparticles and their application in controlling of microbial growth and photo-catalytic degradation of dyes

“…HPLC analysis indicated that some compounds including catechin, ellagic acid, ferulic acid, daidzein, kaempferol, and hesperetin not detected according the injected standards. Gentscheva et al [33] reported the presence of naringenin and quercetin in several extracts of algae.…”

The Protective Effects of Blue-Green Algae (Spirulina) Against Arsenic-Induced Differences in Lipid Panel and Hematological Parameters in Female Rats (Rattus norvegicus)

“…This regimen resulted in a decrease in serum cholesterol, triglyceride, LDL, and VLDL levels, while there was an observable increase in the serum HDL level. Gentscheva et al [50] reported that Sp reduced serum cholesterol, triglyceride, LDL, and VLDL when volunteers were given a 4gm/day oral dose. In line with these studies, Sp (4.2 gm/day) was added for eight weeks to the diet of 30 Japanese males with high cholesterol, mild hypertension, and hyperlipidemia.…”

In vitro anticancer, antioxidant and antibacterial activities of crude extract prepared from Enteromorpha intestinalis habited in Jeddah, Saudi Arabia

“…For example, Pradhan et al (2021) conducted E. intestinalis contains 60 mg of gallic acid and 625 mg of rutin equivalents per gram of extract, in terms of total phenol and flavonoids. The study by Gentscheva et al (2022) also focused on U. intestinalis containing rutin and polyphenols as the highest total content. Phenolic compounds were detected by HPLC analysis in the work of Abu Samra et al (2023) confirmed that Enteromorpha sp.…”

“…Among the flavonoids, rutin, quercetin, naringin, kaempferol, and myricetin demonstrated the most pronounced antioxidant behavior. Quercetin exhibits superior antioxidant efficacy against free radicals that are soluble in both water and fat ( Gentscheva et al, 2022 ). Rutin, in particular, is a phytochemical with numerous biological effects, such as analgesic, antiarthritic, neuroprotective, and antiviral activity ( Zaragoza et al, 2021 ).…”