Screening Of Phytochemical, Antioxidant Activity And Anti-Bacterial Activity Of Marine Seaweeds

Objective: Phytochemical is naturally present in the seaweeds which biologically play a significant role. The intention of this study was designed to screen the phytochemical constituents and antimicrobial potential of selected seaweed collected from Rameshwaram and Tuticorin Southern coast of India.Methods: The present study investigated the presence of phytochemical constituents and also total phenol, total carbohydrate and total protein quantity of the brown seaweed. Dictyopteris delicatula, Padina gymnospora, Acanthophora spicifera, Portieria hornemannii and Ulva faciata were extracted with solvents having different polarities like methanol, ethanol, chloroform and water and screened for the phytochemical constituents, total phenol, total carbohydrate, total protein and DPPH with standard procedure. The antibacterial activities of the seaweeds were examined by agar well diffusion method.Results: Among the five seaweeds, U. faciata showed the maximum number of active constituents in the methanol extract likewise P. gymnospora was found to have a number of diligent compounds in ethanol extract. A. spicifera showed minimum compounds in ethanol as well as chloroform extract. Moreover A. spicifera, P. hornemannii have shown the superior quantity of protein and carbohydrate when compared to other species. The scavenging activity of methanol extracts at 5 mg/ml concentration P. hornemannii shows 18.2% and A. spicifera possess 17.1%. In the antibacterial activity, methanol extracts of all the seaweed showed a potential inhibitory activity against B. cereus and P. aeruginosa compared to other pathogens.Conclusion: The crude extract of seaweed manifest preferable antimicrobial and antioxidant activities, hence in the future, it would be good if it is further taken for treatment of human diseases or as new antimicrobial agents to replace synthetic antimicrobial agents.

An overview of odoriferous marine seaweeds of the Dictyopteris genus: insights into their chemical diversity, biological potential and ecological roles

ABSTRACT Since the middle of the twentieth century the marine algae have attracted attention as a source of new drugs. Dictyopteris is an important group of marine seaweeds and is widely distributed in tropical, subtropical and temperate regions. This genus is known by its characteristic "ocean smell". Some species show a distinct phytochemistry, with specific secondary metabolites, including C11-hydrocarbons, sulfur compounds and quinone derivatives, not usually found in marine seaweeds and described for the first time in the literature. Furthermore, several terpenes, steroids and halogenated compounds have been described. This chemical diversity gives it interesting biological properties, including cytotoxic, antimicrobial, antioxidant, anti-inflammatory and anti-herbivory activities. These findings highlight the importance to continue investigations on this genus and the need to compile the data available so far, since the species are quite heterogeneous, notably in relation to the chemical constitution. This paper reviews the literature on the Dictyopteris genus, focusing on its secondary metabolites and biological activities, in order to build the base for further studies.

The antioxidant and anticoagulant activities of polysaccharides isolated from the brown algae Dictyopteris polypodioides growing on the Lebanese coast.

In this study, we attempt to isolate the polysaccharides from the brown seaweed Dictyopteris polypodioides (Dp) growing on the Lebanese coast. The percentages of the main polysaccharide alginic acid were 4.6% in May and 6.25% in July. The extracted yields of Fucoidan, Laminaran and Mannuronan (FLM) and Mannuronan (M) alone were respectively 0.75% and 0.38% in May and 1.15% and 0.67% in July. We performed the infrared spectroscopy in order to reveal the functional groups of alginate and mannuronan. Moreover, a non-destructive technique ¹ H NMR was used to determine the structure of alginate and the distribution of guluronic (G) and mannuronic acid (M) in the chain, allowing us therefore to calculate the ratio M/G. The latter was 0.96 showing a strong ability of alginate to capture heavy metals. The analysis of trace elements showed great amounts of K, Si, Na and Mg in both seasons. Moreover, Dictyopteris appears to be rich in fatty acids (10 items) with palmitic and oleic acids as main fatty acids. Furthermore, the anticoagulant activity of polysaccharides was investigated by activated partial thromboplastin time (APTT) clotting assay and the antioxidant activity was studied by electrolysis method. It has been shown that the FLM and M fractions of Dictyopteris polypodioides have a significant antioxidant and anticoagulant activities. Further investigations are imperative in order to develop new molecules based on these polysaccharides to be used as drugs or for healthcare in general.