Joko Santoso

Polyphenolic compounds from seaweeds: Distribution and their antioxidative effect

Abstract There is no information on presences of polyphenolic compounds in various seaweeds, and also their mechanism as an antioxidant or pro-oxidant. The distribution and antioxidative activities of polyphenolic compounds of twelve species of Indonesian and Japanese seaweeds were studied, comparing with those of commercial polyphenolic compounds. Fish oil emulsion was used in this study, and incubated at 50°C for 3 hours. Peroxide value (POV), scavenging effect and Fe 2+ chelating were determined as oxidation markers. Eisenia bicyclis contained catechin and its isomers, whereas Caulerpa racemosa, Kappaphycus alvarezii, Monostroma nitidum, Undaria pinnatifida and Laminaria religiosa did not contain catechin and its isomers. Catechol was found in all Japanese seaweed samples, except E. bicyclis . The highest concentrations of flavonoids were found in M. nitidum , whereas almost all of flavonoids could be found in U. pinnatifida . Extracts of Hizikia fusiformis had the best antioxidant power in both absence and presence of Fe 2+ in fish oil emulsion. The highest of scavenging effects was found in morin, followed by rutin and extract of seaweeds ( H. fusiformis and U. pinnatifida ). Catechin and gallic acid had the highest effects of Fe 2+ chelating, and the smallest Fe 2+ chelating was found in both of extract seaweeds ( H. fusiformis and U. pinnatifida ).

Characterization and Alkaline Pretreatment Lignocellulose of Cabomba caroliniana and Its Role to Secure Sustainable Biofuel Production

Lignocellulose is a component of plant fiber and consists of cellulose, hemicellulose, and lignin. High concentrations of lignin inhibit the access of cellulose-degrading enzymes in the process of hydrolysis. The aims of this research were to characterize the structure of lignocellulose from the aquatic plant C. caroliniana fresh and after pretreatment and to determine the optimum alkali concentration (NaOH 3% or 6%), temperature (55 °C or 80 °C), and pretreatment time (6 h or 12 h) for maximum degradation of lignin. Lignocellulose from fresh C. caroliniana contained 17.30 ± 0.13%, hemicellulose, 14.03 ± 0.32% cellulose, and 11.14 ± 0.68% lignin. The lowest yield of regenerated biomass (14.84 ± 0.36%) and the highest lignin extraction (3.56 ± 0.03 mg L−1) were obtained using 6% NaOH at a temperature of 80 °C for 12 h. Structural analysis of samples gave values of peak intensity for cellulose at 899 cm−1 and 1,200 cm−1; hemicellulose peak intensity was 1,161 cm−1. For fresh samples, the lignin peak intensity was 1,543 cm−1. Surface morphology of the sample showed changes in the plant network, which was disconnected and not compact. Alkaline pretreatment could be advantageous in the bioethanol production process and increase bioethanol fuel availability, thus becoming fundamental in realizing energy security.

Physico Chemical Characteristic of Kappa Carrageenan Degraded Using Hydrogen Peroxide

Abstract Kappa carrageenan is polysaccharide that widely used in food, pharmaceutical, cosmetic, textile and printing industries as coagulate agent, stabilizer and gelling agent. Hydrogen peroxide (H2O2) is strong oxidator to degrade polysaccharide. Hydrogen peroxide has some advantades such as cheap, easy to get and savety environment. Degradation method using hydrogen peroxide is a technology based on establishment radical hydoxile reactive that attack the glycosidic of polysaccharides as a result reducing in molecular weight of polysaccharide. The aims of this study were to analyze the effect of hydrogen peroxide concentration, temperature and degradation time to molecular weight of refined kappa carrageenan. Structural changes on kappa carrageenan degradation were characterized by viscometer, SEM and FTIR. Hydrogen peroxide concentration, temperature and degradation time were significantly reducing molecular weight and changes in the structural function of refined kappa carrageenan. The lowest molecular weight of refined kappa carrageenan degraded was obtained from the treatment 3% of hydrogen peroxide at temperature 80°C and degradation time for 4 hours.

Nutritional Composition and Topoisomerase Inhibitor Activity of Ethnomedicinal Marine Mollusk Nerita albicilla

DNA topoisomerases (topo) I and II are molecular targets of several potent anticancer agents. Thus, inhibitors of these enzymes are potential candidates for anticancer development. Traditionally, Nerita albicilla had been used in Kei Island, Southern Maluku, Indonesia to treat liver disease including cancer. The paper reports on the chemical composition of Nerita albicilla and its topo I inhibitor of hexane, ethyl acetate and methanol extracts. Topoisomerase-I inhibitor activity was determined using the method reported by TopoGEN. The proximate analysis described that Nerita albicilla dried powder contained 12.45% ± 0.05% moisture; 9.17% ± 0.03% ash; 62.05% ± 0.10% protein; 5.58% ± 0.08% fat; 6.60% ± 0.02% crude fiber and 4.15% ± 0.24% carbohydrate (by difference). Furthermore, the protein consisted of 11 essential amino acids and six non-essential amino acids. It contained significant amount of branched-chain amino acids (BCAA) valine, leucine, isoleucine (a total of 187.8 mg g -1 protein) and lower content of aromatic amino acids phenylalanine, tyrosine and histidine (a total of 111.26 mg g -1 protein). The protein score was 92.2. The yield of hexane, ethyl acetate and methanol extracts of Nerita albicilla were 2.05% ± 0.05%, 1.56% ± 0.06% and 6.99% ± 0.14%, respectively. All extracts showed topoisomerase-I inhibitor activities. Minimum inhibitory concentration (MIC) of methanol extract was 2.50 µg mL -1 . Chemical screening of the extracts showed that they contained steroidal and alkaloid compounds. The investigation revealed that Nerita albicilla contains active compounds that could be potential for nutraceutical or pharmaceutical development.