Short-chain β-manno-oligosaccharides from copra meal: structural characterization, prebiotic potential and anti-glycation activity

Size-exclusion chromatography, HR-ESI-MS and FT-IR of copra meal hydrolyzed by ManB-1601 showed the presence of oligosaccharides (CM-β-MOS) having a degree of polymerisation (DP) between 2 and 4. Thermal decomposition studies of the purified CM-β-MOS (DP 2, 3 and 4) showed mass loss at high temperatures (135.8 °C to 600 °C). DP2, DP3 and DP4 CM-β-MOS were adjudged as un-substituted Manβ-4Man, Manβ-4Manβ-4Man and Manβ-4Manβ-4Manβ-4Man, respectively, using NMR (¹H and ¹³C) studies. During fermentation, purified CM-β-MOS supported the growth of Lactobacillus sp. and inhibited enteropathogens (Escherichia coli, Listeria monocytogenes and Salmonella typhi). Acetate was the predominant short-chain fatty acid produced by Lactobacillus sp. RT-PCR studies of L. plantarum WCFS1 fed with CM-β-MOS showed up-regulation (up to 6.7-fold) of the cellobiose utilization operon (pts23C and pbg6) and oligo-sucrose utilization loci (pts1BCA and agl2). Biochemical (free amino groups, carbonyl and fructosamine content), fluorescence (AGEs-specific and intrinsic) and molecular docking studies suggested the anti-glycation potential of CM-β-MOS.

Chemical composition, nutraceuticals characterization, NMR confirmation of squalene and antioxidant activities of Basella rubra L. seed oil

Basella rubra (Malabar spinach) is a commonly consumed green leafy vegetable in southern parts of India. The chemical composition, nutraceuticals characterization, squalene Nuclear Magnetic Resonance (NMR), in vitro antioxidant activities and cytotoxicity of B. rubra seed oil (33.08%) was investigated. Gas chromatography-mass spectrometry (GC/MS) analysis revealed the presence of palmitic (27.21 μmol%), oleic (33.83 μmol%) and linoleic acid (26.02 μmol%) with a total of 64.38 μmol% unsaturated fatty acids respectively. HPLC nutraceutical characterization showed a major constituent of gallic acid (11.23 mg%), γ-tocopherols (17.74 mg%), cycloartenylferulate (1.7 mg%), and squalene (1 g%). Squalene was further recovered (98%), purified (99.9%), and confirmed through 1H and 13C NMR. The in vitro antioxidant activities recorded by using 2,2-diphenyl-1-picrylhydrazyl (EC50 = 6 mg mL-1), ferric reducing antioxidant power (361.85 mM of Trolox Eq./100 g) and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (EC50 = 56.19 mg mL-1) scavenging activity. In vitro cytotoxicity assessed on 3T3-L1 showed good cell survival without any toxicity (upto 400 μg mL-1). B. rubra seed oil has proven nutraceuticals and antioxidant potentials with least toxicity which can be recommended for functional foods applications.

GH36 α-galactosidase from Lactobacillus plantarum WCFS1 synthesize Gal-α-1,6 linked prebiotic α-galactooligosaccharide by transglycosylation

α-Galactosidases are potent industrial glycoside hydrolases which are relatively less explored for their transglycosylation potential, especially from Lactobacillus genera. A GH36 α-galactosidase from Lactobacillus plantarum WCFS1 was cloned and over expressed in Hi-control Escherichia coli BL21(DE3). Ni-NTA affinity gel chromatography resulted in purified α-galactosidase (LpαG; specific activity 3077.35 U mg^-1) having a monomeric weight of ~80 kDa with 29.3% yield. Size exclusion chromatography of LpαG showed native molecular mass of ~240.5 kDa. LpαG displayed optimum activity at pH 6 and 37 °C. The K_m,V_max and k_cat/K_m of LpαG towards pNPαGal were found to be 0.93 mM and 714.3 μmol ml^-1 min^-1 and 12,075 s^-1 mM^-1, respectively. LpαG displayed maximum transglycosylation activity towards melibiose substrate (as both donor and acceptor) and synthesized majorly a trisaccharide with 0.26 mg ml^-1 yield. Nuclear magnetic resonance (NMR) characterization revealed that trisaccharide consist of only single species of α-linked galactooligosaccharide (manninotriose; α-d-Galp-(1 → 6)-α-d-Galp-(1 → 6)-d-Glcp) with α-(1 → 6) regioselectivity. Manninotriose displayed prebiotic property by supporting the growth of probiotic L. plantarum WCFS1 and Bifidobacteria adolescentis DSM 20083.

Solvent suppression in DNP enhanced solid state NMR

We show how DNP enhanced solid-state NMR spectra can be dramatically simplified by suppression of solvent signals. This is achieved by (i) exploiting the paramagnetic relaxation enhancement of solvent signals relative to materials substrates, or (ii) by using short cross-polarization contact times to transfer hyperpolarization to only directly bonded carbon-13 nuclei in frozen solutions. The methods are evaluated for organic microcrystals, surfaces and frozen solutions. We show how this allows for the acquisition of high-resolution DNP enhanced proton-proton correlation experiments to measure inter-nuclear proximities in an organic solid.

Three centered hydrogen bonds of the type CO⋯H(N)⋯X–C in diphenyloxamide derivatives involving halogens and a rotating CF3 group: NMR, QTAIM, NCI and NBO studies

The existence of three centered CO⋯H(N)⋯X–C hydrogen bonds (H-bonds) involving organic fluorine and other halogens in diphenyloxamide derivatives has been explored by NMR spectroscopy and quantum theoretical studies.

Pure shift NMR approach for fast and accurate extraction of heteronuclear couplings

An NMR experiment for the direct determination of heteronuclear couplings from the severely overlapped ¹H NMR spectrum.

Quick re-introduction of selective scalar interactions in a pure-shift NMR spectrum

A new 1D NMR experiment cited as ‘Quick G-SERF’, which re-introduces selective proton–proton scalar interactions in a pure shift spectrum during real time data acquisition, is reported.

A versatile ternary ionic complex for chiral discrimination of molecules with diverse functionalities using 1H NMR

A novel chiral solvating agent for enantiodiscrimination by NMR spectroscopy is introduced.

Niosomes: novel sustained release nonionic stable vesicular systems--an overview

Vesicular systems are novel means of delivering drug in controlled manner to enhance bioavailability and get therapeutic effect over a longer period of time. Niosomes are such hydrated vesicular systems containing nonionic surfactants along with cholesterol or other lipids delivering drug to targeted site which are non toxic, requiring less production cost, stable over a longer period of time in different conditions, so overcomes drawbacks of liposome. Present review describes history, all factors affecting niosome formulation, manufacturing conditions, characterization, stability, administration routes and also their comparison with liposome. This review also gives relevant information regarding various applications of niosomes in gene delivery, vaccine delivery, anticancer drug delivery, etc.