<i>Antigonon leptopus</i>: a potent biological source for extermination of fish bacterial pathogens <i>Providencia</i> and <i>Aeromonas</i>

<div><p>This study pertains to the phytochemical components and the biological properties of the weed, <i>Antigonon leptopus</i> Hook. & Arn. (AUT/PUS/064). Phytochemical screening of methanolic leaf extract of <i>A. leptopus</i> revealed the presence of saponin, phenolic compounds, tannins, flavonoids, alkaloids, fixed oils and amino acids. Accordingly, 12 phytochemical components were analysed and characterised by GC–MS. Antibacterial activity was evaluated against fish and clinical pathogens. Fish pathogens, <i>Providencia vermicola</i> (MTCC 5578) and <i>Aeromonas hydrophila</i> (MTCC 646) were more sensitive to the methanolic leaf extract than clinical pathogens. A useful information was obtained from the phytochemistry of <i>A. leptopus</i> leaves, which would pave way to further applications to treat fish diseases and for utility in the pharmaceutical field.</p></div

Isolation, structural elucidation and antiplasmodial activity of fucosterol compound from brown seaweed<i>, Sargassum linearifolium</i> against malarial parasite <i>Plasmodium falciparum</i>

<p>The brown seaweed, <i>Sargassum linearifolium</i> (Turner) C. Agardh, 1820 is commonly available along the south-east coast of India. Its compound fucosterol was isolated and confirmed through spectral characterisation and chemical transformation methods. The antiplasmodial effect of the isolated fucosterol was investigated against the 3D7 chloroquine sensitive <i>Plasmodium falciparum</i> strain, parasitaemia percentage was determined at 48 h and morphological change was studied through microscopic examination after Giemsa staining. A perceptible antiplasmodial effect was produced by fucosterol compound against the <i>P. falciparum</i> and positive control, chloroquine with the IC₅₀ values (μg/mL) of 7.48 and 12.81, respectively. Fucosterol showed higher antiplasmodial activity as compared to chloroquine. It is inferred that both the fucosterol and chloroquine could have inhibited the schizont stage of the parasite during the intra-erythrocyte asexual development. The findings underline the usefulness of the seaweed-based fucosterol and further studies are warranted.</p