Natural product chemisry Research Papers (original) (raw)
Marine invertebrates are known to contain metabolites with unprecedented diversity in terms of their molecular structures and bioactivities. The majority of the invertebrate phyla have been accounted for but only several studies on... more
Marine invertebrates are known to contain metabolites with unprecedented diversity in terms of their molecular structures and bioactivities. The majority of the invertebrate phyla have been accounted for but only several studies on antioxidant activities have been made on Philippine sea stars. The main aim of this research is to determine the total flavonoids content, total phenolics content, and antioxidant activities of ethyl acetate and methanolic extract of Linckia laevigata and Acanthaster planci. Standard methods in plants were utilized to determine TFC and TPC while TEAC, DPPH, and FRAP assays were used to evaluate antioxidant activities. No flavonoids were detected in both species for the two solvents utilized while total phenolics were detected in both species and solvents utilized. Total phenolics were noted to be higher in methanol compared to ethyl acetate extract. A. planci also consistently recorded higher TPC for both solvents compared to L. laevigata. Consistently in DPPH and TEAC, A. planci had higher antioxidant capacity compared to L. laevigata for both solvents utilized. Overall, lower antioxidant capacities were observed for all three assays which could be due to the method of sample preparation, especially in the drying of samples which could have affected the natural antioxidants present in the body parts of the sea stars. It is recommended that conservation measures be implemented to protect these species which are a potential source of novel antioxidant compounds.
Cardiovascular diseases (CVD) are an important cause of death worldwide. Anthocyanins are a subgroup of flavo-noids found in berries, flowers, fruits and leaves. In epidemiological and clinical studies, these polyphenols have been... more
Cardiovascular diseases (CVD) are an important cause of death worldwide. Anthocyanins are a subgroup of flavo-noids found in berries, flowers, fruits and leaves. In epidemiological and clinical studies, these polyphenols have been associated with improved cardiovascular risk profiles as well as decreased comorbidities. Human intervention studies using berries, vegetables, parts of plants and cereals (either fresh or as juice) or purified anthocyanin-rich extracts have demonstrated significant improvements in low density lipoproteins oxidation, lipid peroxidation, total plasma antioxidant capacity, and dyslipidemia as well as reduced levels of CVD molecular biomarkers. This review discusses the use of anthocyanins in animal models and their applications in human medicine, as dietary supplements or as new potent drugs against cardiovascular disease.
Bioactive compounds for drug discovery are increasingly extracted and purified from natural sources including marine organisms. Heparin is a therapeutic agent that has been used for several decades as an anticoagulant. However, heparin is... more
Bioactive compounds for drug discovery are increasingly extracted and purified from natural sources including marine organisms. Heparin is a therapeutic agent that has been used for several decades as an anticoagulant. However, heparin is known to cause many undesirable complications such as thrombocytopenia and risk of hemorrhage. Hence, there is a need to find alternatives to current widely used anticoagulant drugs. Here, we extract a sulfated polysaccharide from sea hare, that is, Bursatella leachii viscera, by enzymatic digestion. Several analytical approaches including elemental analysis, Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and high-performance liquid chromatography−mass spectrometry analysis show that B. leachii polysaccharides have chemical structures similar to glycosaminoglycans. We explore the anticoagulant activity of the B. leachii extract using the activated partial thromboplastin time and the thrombin time. Our results demonstrate that the extracted sulfated polysaccharide has heparin-like anticoagulant activity, thus showing great promise as an alternative anticoagulant therapy.
Objective: This study was taken to examine the cytotoxicity of the bioactive fraction isolated from marine sponge Calthropella sp. as a preliminary anticancer assay and identify its bioactive compounds.Methods: The cytotoxic activity was... more
Objective: This study was taken to examine the cytotoxicity of the bioactive fraction isolated from marine sponge Calthropella sp. as a preliminary anticancer assay and identify its bioactive compounds.Methods: The cytotoxic activity was assessed by 3-(4,5-dimethylthiazol-2-y1)-2,5-diphenyltetrazolium bromide assay against three human cancer cell lines, namely human breast (MCF-7), human lung (H-460), and human liver (HepG-2). The bioactive compounds were identified using a high-resolution liquid chromatography–mass spectroscopy (LC–MS).Results: The active fraction 7 showed moderate to strong cytotoxic activity on all cell lines tested and promising a strong potent cytotoxicity against MCF-7 cell lines with IC50 value as low as 1.925 μg/mL comparable to control, cisplatin (IC50 0.977 μg/mL). In regard to the promising bioactive compounds, the high-resolution LC–MS predicted the existing of several known compounds such as bengamide Q, clavepictine A, 4’-N-methyl-5’- hydroxystaurospor...
The purpose of this study was to assess the ethnobotanical uses of Plecranthusesculentus N.E.Br in Makoni district, Zimbabwe as well as to evaluate the phytochemical profile of aqueous acetonic extract of the plant tubers using UV-Visible... more
The purpose of this study was to assess the ethnobotanical uses of Plecranthusesculentus N.E.Br in Makoni district, Zimbabwe as well as to evaluate the phytochemical profile of aqueous acetonic extract of the plant tubers using UV-Visible spectrophotometry, Fourier transform-Infrared (FTIR) analysis and high performance liquid chromatography (HPLC).Face to face interviews were conducted among residents of Makoni district in order to gather information about the ethnobotanical uses of Plecranthusesculentus. The phytochemical profile of Plecranthusesculentus tubers was determined using UV-Visible spectrophotometry and FTIR analysis after solvent extraction using conventional phytochemical extraction protocols. High performance liquid chromatography (HPLC) analysis was used to confirm the presence of two selected phenolic compounds.Data from interviews showed that Plecranthusesculentus is widely used as food and folklore medicine in Makoni district, Zimbabwe. The UV-Visible and FTIR analysis of the tuber extract showed the presence of phytochemical compounds with organic chromophores including phenyl, organic hydroxyl, amines, carboxyl, carbonyl, acyl, alkyl and aromatic compounds. HPLC analysis confirmed the presence kaempferol and vanillic acid in the tuber extract.The study establishes the common ethnobotanical uses of Plecranthusesculentus and avails data on the phytochemical profile of Plecranthusesculentus tubers found in Zimbabwe. It also promotes the use, further study and conservation of the plant basing on its potential phyto-pharmaceutical importance.
Bioactive compounds for drug discovery are increasingly extracted and purified from natural sources including marine organisms. Heparin is a therapeutic agent that has been used for several decades as an anticoagulant. However, heparin is... more
Bioactive compounds for drug discovery are increasingly extracted and purified from natural sources including marine organisms. Heparin is a therapeutic agent that has been used for several decades as an anticoagulant. However, heparin is known to cause many undesirable complications such as thrombocytopenia and risk of hemorrhage. Hence, there is a need to find alternatives to current widely used anticoagulant drugs. Here, we extract a sulfated polysaccharide from sea hare, that is, Bursatella leachii viscera, by enzymatic digestion. Several analytical approaches including elemental analysis, Fourier-transform infrared spectroscopy, nuclear magnetic resonance, and high-performance liquid chromatography−mass spectrometry analysis show that B. leachii polysaccharides have chemical structures similar to glycosaminoglycans. We explore the anticoagulant activity of the B. leachii extract using the activated partial thromboplastin time and the thrombin time. Our results demonstrate that ...