1.Chemical structure of the arabinogalactan protein from gum ghatti and its interaction with bovine serum albumin.
Ghosh K1, Ray S1, Ghosh D1, Ray B2. Carbohydr Polym. 2015 Mar 6;117:370-6. doi: 10.1016/j.carbpol.2014.09.084. Epub 2014 Oct 7.
Exudate gums, because of their beneficial properties, have been significant items of international trade in various industries for centuries. This manuscript sets out to gain insight into the fine structural details of an arabinogalactan protein (AGP) of gum ghatti (Anogeissus latifolia gum). The presence of a highly branched 554 kDa AGP having 1,6-linked Galp, 1,2-linked Manp, 1,3-linked Araf and 1,4-linked GlcpA main chain, substituted at O-4,6 of 1,2-linked Manp, and O-3/O-3,4 of 1,6-linked Galp residues by Araf, Arap and Galp units was revealed by chemical, chromatographic, ESMS, and NMR analyses. In particular, ESMS analysis of per acetylated oligomeric fragments derived from AGP by Smith degradation followed by acetylation was described as a commanding tool for providing critical structural information on a spectrum of glycerol tagged oligosaccharides. In addition, formation of an electrostatically driven complex between the isolated AGP and bovine serum albumin resulting in changes in the microenvironment around the tryptophan residues of BSA was established.
2.Gum ghatti and Fe₃O₄ magnetic nanoparticles based nanocomposites for the effective adsorption of rhodamine B.
Mittal H1, Mishra SB. Carbohydr Polym. 2014 Jan 30;101:1255-64. doi: 10.1016/j.carbpol.2013.09.045. Epub 2013 Sep 22.
This article reports the development of a new nanocomposite using gum ghatti crosslinked with poly(acrylic acid-co-acrylamide) reinforced with iron oxide magnetic nanoparticles. The nanocomposite was characterized through BET, FT-IR, XRD, SEM-EDX, TGA and TEM and applied for the removal of RhB. Different optimized adsorption parameters were adsorbent dose (0.8 g/L) and pH (7.0). The adsorption isotherm data was used to study Langmuir, Freundlich and Dubinin-Kaganer-Radushkevich isotherm models. The value of correlation coefficient confirmed the applicability of Langmuir isotherm model with maximum adsorption efficiency of 654.87 mg/g. The adsorption kinetics data showed pseudo second order reaction. Thermodynamic studies showed that the adsorption process was endothermic and spontaneous. Moreover, the adsorbent was successfully utilized for successive three cycles for the adsorption-desorption of RhB.
3.A study on the adsorption of methylene blue onto gum ghatti/TiO2 nanoparticles-based hydrogel nanocomposite.
Mittal H1, Ray SS2. Int J Biol Macromol. 2016 Mar 17;88:66-80. doi: 10.1016/j.ijbiomac.2016.03.032. [Epub ahead of print]
The objective of this work was to study the isotherm and kinetic models for the adsorption of methylene blue (MB) onto a TiO2 nanoparticle (TiO2NP)-containing hydrogel nanocomposite (HNC) of polyacrylamide-grafted gum ghatti (PAAm-g-Gg). The grafting of PAAm onto Gg was conducted using N,N'-methylene-bis-acrylamide (MBA) as a crosslinker, and different weight percentages of TiO2NPs were incorporated into the hydrogel matrix during the grafting reaction. The graft co-polymerization and the formation of the HNC were confirmed using FTIR, XRD, BET, SEM, TEM and EDS analyses. The adsorption of MB was studied in batch mode and it was found to be highly dependent on solution pH, ionic strength temperature and adsorbent loading. The MB-adsorption process followed the pseudo-second-order rate model and Langmuir adsorption isotherm with a maximum adsorption capacity of 1305.5mgg-1. Thermodynamic studies revealed that the adsorption of MB onto the HNC surface was spontaneous, endothermic and through a process of physisorption.
4.Antibacterial activity of biogenic silver nanoparticles synthesized with gum ghatti and gum olibanum: a comparative study.
Kora AJ1, Sashidhar RB2. J Antibiot (Tokyo). 2015 Feb;68(2):88-97. doi: 10.1038/ja.2014.114. Epub 2014 Aug 20.
Presently, silver nanoparticles produced by biological methods have received considerable significance owing to the natural abundance of renewable, cost-effective and biodegradable materials, thus implementing the green chemistry principles. Compared with the nanoparticles synthesized using chemical methods, most biogenic silver nanoparticles are protein capped, which imparts stability and biocompatibility, and enhanced antibacterial activity. In this study, we compared the antibacterial effect of two biogenic silver nanoparticles produced with natural plant gums: gum ghatti and gum olibanum against Gram-negative and Gram-positive bacteria. Bacterial interaction with nanoparticles was probed both in planktonic and biofilm modes of growth; employing solid agar and liquid broth assays for inhibition zone, antibiofilm activity, inhibition of growth kinetics, leakage of intracellular contents, membrane permeabilization and reactive oxygen species production.