@article {1013, title = {Analysis of Bioactive Compounds from Different Algae Samples Extracted with Ultrasound: Characterizations, Phytochemical Contents and Antioxidant Potentials}, journal = {Pharmacognosy Research}, volume = {14}, year = {2022}, month = {December 2021}, pages = {35-44}, type = {Original Article}, chapter = {35}, abstract = {

Introduction: Algae are a significant bioactive compounds source, with variation in biological functions including antioxidant, anti-inflammatory and antiviral. Both microalgae and macroalgae biomass are a rich source of high value nutraceuticals and other bio products of commercial value, making algae worth investigating into. Objectives: To analyze bioactive phytochemicals and their antioxidants properties of extracts from algae from lake Taihu, Microcystis aeruginosa, Spirogyra and Seaweed extracted with ultrasound assisted method in comparison to the traditional extraction method, and a subsequent use of the residue in producing biochar. Materials and Methods: The different algae species viz Microcystis aeruginosa, Spirogyra and Seaweed were subjected to ultrasonic and thermostatted water bath extraction with a 70\% ethanol and 30\% water (v/v) as solvent. The extracts were characterized using gas chromatography-mass spectrometry. The total phenol and flavonoid and antioxidant activities were assessed in vitro viz hydroxyl radical ({\textbullet}OH) scavenging activity, ferric- reducing antioxidant property, total antioxidant capacity and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) activity. Results: The chemical analysis indicated the existence of bioactive compounds such as alkaloids, phenols, tannins, flavonoids, terpenoids, steroids, proteins, carbohydrates, phytosterols, quinones, saponins, coumarins and glycosides. In vitro screening of the extracts also showed good antioxidant capacity (hydroxyl radical ({\textbullet}OH) scavenging activity, ferricreducing antioxidant property, total antioxidant capacity and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) activity), the extracted compounds are of biological and pharmacological importance. The ultrasound assisted extraction method significantly increased yield with 27.0\% in comparison to conventional method with 18.6\%. Conclusion: The study showed the different algae species were enriched with phytochemicals and that the ultrasound assisted method was an effective extraction method environmentally benignant. A complete utilization of algae biomass was achieved after biochar was made from the residue.

}, keywords = {Algae species, Antioxidant activity., ethanol, Phytochemicals, Ultrasound assisted extraction}, doi = {10.5530/pres.14.1.7}, url = {https://phcogres.com/fulltext/v14i1/105530pres1417.html}, author = {Jakpa Wizi and Lixiao Ni and Williams Kweku Darkwah and Li Xianglan} } @article {61, title = {High-Performance Liquid Chromatography Analysis and Antioxidant Activities of Extract of Azadirachta indica (Neem) Leaves}, journal = {Pharmacognosy Research}, volume = {12}, year = {2021}, month = {February 2020}, pages = {29-34}, type = {Original Article}, chapter = {29}, abstract = {

Background: Extracts from Azadirachta indica (A. indica) tend to provide numerous health benefits including antioxidant activity. The main objectives for this research were to use standard procedures to determine total phenols, total alkaloids, total flavonoid, 1,1-diphenyl-2-picrylhydrazine (DPPH)-scavenging activity, ferric reducing power, and total antioxidant capacity and analyze active components of the extracts using high-performance liquid chromatography (HPLC). Materials and Methods: In vitro antioxidant potential of the A. indica extract was evaluated using DPPH and total antioxidant ability assays. Ferric reducing power ability of the extract was also examined using tannic acid and ascorbic acid as standard. Concentrations of plant extracts ranging from 0.02 to 0.10 mg/ml were prepared and mixed with appropriate volumes of reagents. Results: Methanol extract of A. indica exhibited higher content of phytochemical compounds (alkaloid = 1.9 mg QE/g; flavonoids = 3.5 mg QE/g; and phenols = 4.9 mg QE/g) at concentration 0.1 mg/ml compared to the acetone/water extract (alkaloid = 1.7 mg QE/g; flavonoids = 1.4 mg QE/g; and phenols = 2.6 mg QE/g). An overall trend found in the present study highlights the fact that the methanol extracts have better antioxidant capacities (DPPH, total antioxidant ability, and ferric reducing antioxidant property) than the acetone/water extract. HPLC analysis conducted also reveals seven peaks for methanol extract and six for acetone{\textendash}water extract with different heights. Conclusion: HPLC analysis of A. indica extracts exhibited the presence of azadirachtin compound. The study showed that the extracts can competently protect the body against oxidative stress and therefore can be used as a source of potent natural antioxidant compounds.

}, keywords = {Antioxidant activity, Azadirachta indica, High-performance liquid chromatography analysis, Leaf extracts, Phytochemicals}, doi = {10.4103/pr.pr_14_19}, author = {Emmanuel Ekow Biney and Matthew Nkoom and Williams Kweku Darkwah and Joshua Buer Puplampu} }