Indian Council of Agricultural Research


Sulfated N-acetylglucosamino-glucuronopyranosyl-arabinopyranan from seafood Amphioctopus neglectus attenuates angiotensin-II prompted cardiac hypertrophy

Angiotensin converting enzyme (ACE) is amultifunctional enzymeinvolved in translation of angiotensin-I (AngI) to vasoconstrictor angiotensin-II (AngII). A sulfated N-acetylglucosamino-glucuronopyranosyl-arabinopyranan characterized as poly-[(2-methoxy-?-arabinopyranosyl)-(1 ? 3)-(?-glucurono)-(1 ? 4)-(2-acetamido-2- deoxy-3,6-di-O-sulfonato-?-glucopyranose)] was purified and reported first time from the edible portion of Amphioctopus neglectus and evaluated for various pharmacological properties. The polysaccharide exhibited potential ACE attenuation property (IC50 0.11 mg mL?1), whereas molecular docking simulations displayed its efficient binding at the ACE active site with lesser inhibitory constant (Ki) of 17.36 nM and binding energy (?10.59 kcal mol?1). The in-vitro analysis showed that the studied polysacharide attenuated AngII prompted cardiac hypertrophy at 50 ?g mL?1 in the cardiomyoblast cells, whereas 48% reduction in cellular surface area with extended viability could be correlated with anti-hypertrophic properties of the studied polysaccharide. The sulfated N-acetylglucosamino-glucuronopyranosyl-arabinopyranan purified fromA. neglectus could function as a prospective functional lead against the pathophysiological conditions leading to hypertension.


Moving away from traditional antibiotic treatment: can macrocyclic lactones from marine macroalga-associated heterotrophy be the alternatives?

Intertidal red algae Hypnea valentiae associated Bacillus amyloliquefaciens MTCC 12716 revealed potential inhibitory effects on the growth of drug-resistant pathogens. In the genome of B. amyloliquefaciens MTCC 12716, biosynthetic gene clusters encoding antibacterial metabolites were predicted, which might be expressed and contributed to the broad-spectrum anti-infective activity. Three homologue members of the 24-membered macrocyclic lactone family, named as bacvalactones 1–3 bearing 13-O-ethyl (1); 15-O-furanyl-13-O-isobutyl-7-O-propyl-propanoate (2); and 15-O-furanyl-13-O-isobutyl-7-O-propyl-propanoate-7,24-dimethyl (3) functionalities, were acquired through bioactivity-guided purification. The macrocyclic lactones displayed bactericidal activity against opportunistic pathogens causing nosocomial infections, for instance, methicillin–resistant Staphylococcus aureus (MRSA), vancomycin–resistant Enterococcus faecalis (VREfs), and multidrug-resistant strains of Pseudomonas aeruginosa and Klebsiella pneumonia with MIC ??3.0 ?g/mL, whereas standard antibiotics ampicillin and chloramphenicol were active only at concentrations of ??6.25 mg/mL. The biosynthetic pathway of macrocyclic lactones that are generated by trans-AT polyketide synthases through stepwise extension of an acetyl starter unit by eleven sequential Claisen condensations with malonyl-CoA was established, and the structures were correlated with the gene organization of the mln operon, which encompasses nine genes mln A-I (approximately 47 kb in size). The best binding poses for each compounds (1–3) with Staphylococcus aureus peptide deformylase (SaPDF) unveiled docking scores (??9.70 kcal/mol) greater than that of natural peptide deformylase inhibitors, macrolactin N and actinonin (9.14 and 6.96 kcal/mol, respectively), which supported their potential in vitro bioactivities. Thus, the present work demonstrated the potential of macrocyclic lactone for biotechnological and pharmaceutical applications against emerging multidrug-resistant pathogens.


A new species of white-spotted moray eel from deep waters of Arabian Sea, India

A new species of white-spotted moray eel Gymnothorax smithi sp. nov. is described based on three specimens collected from the southeastern Arabian Sea, India. This is the first deep water report of a moray eel from Indian waters from 200 m depth. This new species is distinguishable from its congeners by the following combination of characters: greyish brown body overlain with white spots of irregular shape, dorsal-fin origin anterior to gill opening, anus positioned slightly behind the mid-point of the body, serrated teeth and a unique vertebral count 3–5 /57/130–132. [Zoobank URL:]


Length-weight relationship, feeding traits and nutritional value of mahi mahi in the south-eastern Arabian Sea

The fork length of the specimens of C. hippurus collected along Karnataka coast ranged from 30- 123 cm and fishes having length range from 33-73 cm represented 79% of the total fish sampled. The estimated b values of C. hippurus for both males and females were less than 3 which indicated negative allometric growth; the fish grows faster in length than weight. The most dominant item recorded in the gut of C. hippurus was pelagic and mesopelagic teleosts. Cephalopods (squids, cuttlefish and octopus) were the second important food constituent while crustaceans consisting of crabs and shrimps formed very less quantity.


Biological observations on the Bengal guitarfish from the Eastern Arabian Sea, India

Biological data for the little known Bengal guitarfish Rhinobatos  annandalei Norman, 1926  (Rhinopristiformes: Rhinobatidae) are presented based on specimens collected from bycatch of commercial shrimp trawlers, gill netters and bag or dol netters operating in the Arabian Sea at depths of 2-70 m off the north-west coast of India. Five hundred ninety three specimens measuring 30.0 to 95.0 cm total length (TL) and weighing between 64.0 to 3300 g total weight (TW) were collected for the study. The length-weight relationships (LWR) were significantly different between the sexes (p<0.001) and the LWR for the combined sexes was derived as TW= 0.000604 TL3.408256 (r2= 0.997). The co-efficients ‘a’ and ‘b’ of the LWR were estimated as 0.000621, 3.410115 (r2= 0.999) for females and 0.000766, 3.333872 (r2= 0.999) for males. The length at maturity (TL50) for females and males was estimated to be 61.0 and 63.3 cm TL, respectively. In a single female, the number of embryos ranged from 2 to 11 and the size at birth was estimated between 25.0 to 30.0 cm TL. The overall sex ratio favoured females at the rate of 1.6:1. An analysis of the stomach contents (%IRI) revealed that R. annandalei  mainly fed on Solenocera spp. (18.7% IRI), along with P. sculptilis (0.5% IRI), P. stylifera (0.4% IRI), Loligo spp. (0.4% IRI) and sciaenids (0.3% IRI). Since, the species is poorly studied and assessed as ‘Data Deficient’ in the IUCN red list criterion, it is anticipated that the biological results from the present study, will update information on the species thereby enabling more effective management decisions.


Production and characterisation of monoclonal antibodies against immunoglobulins of Cirrhinus mrigala

Serum immunoglobulins (Ig) of mrigal Cirrhinus mrigala (Hamilton 1822) immunised with bovine serum albumin (BSA), were purified by affinity chromatography using BSA-CL agarose column. The purified mrigal Ig (m-Ig) was characterised under reducing condition by Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) which revealed two bands of 85 and 26 kDa corresponding to heavy and light chain, respectively. Following fusion of splenocytes from Balb/c mice immunised with purified m-Ig with myeloma cells, three hybridomas showing reactivity with m-Ig were cloned by limiting dilution. The monoclonal antibodies (MAbs) generated by these clones were designated as 3B2-E12, 3B2-F9 and 4C3-B2 and characterised by western blotting and isotyping. Western blot analysis of the supernatant from the three clones with purified m-Ig indicated that, all the three MAbs were specific to heavy chain. Isotyping revealed that 3B2-E12 MAb was of IgG1 isotype whereas the other two MAbs were of IgG2a isotype. Cross reactivity of anti-mrigal Ig MAb (3B2-E12) was observed with serum Ig of Catla catla and Labeo rohita indicating semi-conserved nature of Ig in Indian major carps.


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