7296-64-2Relevant academic research and scientific papers
Immobilization of β-galactosidase onto Sepharose and stabilization in room temperature ionic liquids
Singh, Natasha R.,Narinesingh, Dyer,Singh, Gurdial
, p. 19 - 27 (2010)
The hydrolysis of o-nitrophenyl-β-d-galactopyranoside (ONPG) by β-galactosidase immobilized on Sepharose CL-4B was investigated in five different ionic liquids (ILs), 1-butyl-3-methylimidazolium X-; [X = CF3SO3-, BF4-, PF6-, CH3SO4-and N(CN)2-]. Michaelis-Menten kinetic studies were conducted in phosphate buffer and in the five ionic liquids. For the immobilized enzyme in the ILs, the Km values were lower (0.36-1.2 mmol ONPG) while the Vmax values were higher (0.04-0.008 min- 1) compared to those in aqueous phosphate buffer suggesting a marked increase in the efficiency of the immobilized enzyme in the ionic liquid. For the free enzyme in the ionic liquids, the Km values, in general, were larger (0.45-4.96 mmol ONPG) than those of the immobilized enzyme in the ionic liquid. A postulated mechanism for the hydrolysis is suggested, involving interception of the intermediate oxonium ion species by the counter ion of the ionic liquid, thereby enabling the hydrolysis to occur at a faster rate.
Exopolysaccharide Produced by Probiotic Bacillus albus DM-15 Isolated From Ayurvedic Fermented Dasamoolarishta: Characterization, Antioxidant, and Anticancer Activities
Kalimuthu, Palanisamy,Ma, Yongkun,Mathivanan, Krishnamurthy,Rai, Amit Kumar,Saravanan, Kandasamy,Sathiyanarayanan, Ganesan,Sekar, Soundarapandian,Sudharsan, Kumaresan,Vinothkanna, Annadurai
, (2022/03/31)
An exopolysaccharide (EPS) was purified from the probiotic bacterium Bacillus albus DM-15, isolated from the Indian Ayurvedic traditional medicine Dasamoolarishta. Gas chromatography-mass spectrophotometry and nuclear magnetic resonance (NMR) analyses revealed the heteropolymeric nature of the purified EPS with monosaccharide units of glucose, galactose, xylose, and rhamnose. Size-exclusion chromatography had shown the molecular weight of the purified EPS as around 240 kDa. X-ray powder diffraction analysis confirmed the non-crystalline amorphous nature of the EPS. Furthermore, the purified EPS showed the maximum flocculation activity (72.80%) with kaolin clay and emulsification activity (67.04%) with xylene. In addition, the EPS exhibits significant antioxidant activities on DPPH (58.17 ± 0.054%), ABTS (70.47 ± 0.854%) and nitric oxide (58.92 ± 0.744%) radicals in a concentration-dependent way. Moreover, the EPS showed promising cytotoxic activity (20 ± 0.97 μg mL–1) against the lung carcinoma cells (A549), and subsequent cellular staining revealed apoptotic necrotic characters in damaged A549 cells. The EPS purified from the probiotic strain B. albus DM-15 can be further studied and exploited as a potential carbohydrate polymer in food, cosmetic, pharmaceutical, and biomedical applications.
Bioactive oleanane-type saponins from Hylomecon Japonica
Li, Fei,Ma, Chun-Liu,Qu, Ming-Hui,Wang, Guang-Shu,Wang, Yi-Xiao,Wu, Si-Tong,Yu, Bai-Hong
, (2021/07/19)
Six undescribed oleanane-type saponins, named as Hylomeconosides L-Q, were isolated from the whole herb of Hylomecon Japonica, their structures were determined by analysis of 1D and 2D-NMR (1H–1H COSY, HSQC, and HMBC) spectroscopic data, mass spectrometry (HRESI-MS) and chromatographic data (GC and LC). Their structures were identified as 3-O-β-D-galactopyranosyl-(1 → 2)-β-D-glucuronopyranosyl gypsogenin 28-O-β-D-galactopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-β-L-arabinopyranoside; 3-O-β-D-galactopyranosyl-(1 → 2)-β-D-glucuronopyranosyl gypsogenin 28-O-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-β-D-quinovopyranoside; 3-O-β-D-glucuronopyranosyl gypsogenin 28-O-β-D-xylopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-β-D-quinovopyranoside; 3-O-β-D-xylopyranosyl-(1 → 3)-β-D-glucuronopyranosyl gypsogenin 28-O-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-β-D-quinovopyranoside; 3-O-β-D-galactopyranosyl-(1 → 2)-[α-L-rhamnopyranosyl-(1 → 3)]-β-D-glucuronopyranosyl quillaic acid 28-O-β-D-xylopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-β-D-quinovopyranoside; 3-O-β-D-galactopyranosyl-(1 → 2)-[α-L-rhamnopyranosyl-(1 → 3)]-β-D-glucuronopyranosyl quillaic acid 28-O-β-D-xylopyranosyl-(1 → 3)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 2)-β-D-galactopyranoside. Hylomeconosides L-Q showed selective cytotoxicities against human cancer cell lines A549, AGS, HeLa, Huh 7, HT29 and K562. These results represent a contribution to the chemotaxonomy of the saponins of Hylomecon Japonica and their bioactivities.
New alkali tolerant β-galactosidase from Paracoccus marcusii KGP – A promising biocatalyst for the synthesis of oligosaccharides derived from lactulose (OsLu), the new generation prebiotics
Kalathinathan, Pooja,Pulicherla, Krishnakanth,Sain, Avtar,Gomathinayagam, Sankaranarayanan,Jayaraj, Rama,Thangaraj, Suresh,Kodiveri Muthukaliannan, Gothandam
, (2021/08/03)
The enzyme β-galactosidase can synthesise novel prebiotics such as oligosaccharides derived from lactulose (OsLu) which can be added as a supplement in infant food formula. In this study, the intracellular β-galactosidase produced by the alkaliphilic bacterium Paracoccus marcusii was extracted and purified to homogeneity using hydrophobic and metal affinity chromatography. The purification resulted in 18 U/mg specific activity, with a yield of 8.86% and an 18-fold increase in purity. The purified enzyme was a monomer with an 86 kDa molecular weight as determined by SDS PAGE and Q-TOF-LC/MS. β-Galactosidase was highly active at 50 °C and pH 6–8. The enzyme displayed an alkali tolerant nature by maintaining more than 90% of its initial activity over a pH range of 5–9 after 3 h of incubation. Furthermore, the enzyme activity was enhanced by 37% in the presence of 5 M NaCl and 3 M KCl, indicating its halophilic nature. The effects of metal ions, solvents, and other chemicals on enzyme activity were also studied. The kinetic parameters KM and Vmax of β-galactosidase were 1 mM and 8.56 μmoles/ml/min and 72.72 mM and 11.81 μmoles/ml/min on using oNPG and lactose as substrates. P. marcusii β-galactosidase efficiently catalysed the transgalactosylation reaction and synthesised 57 g/L OsLu from 300 g/L lactulose at 40 °C. Thus, in this study we identified a new β-galactosidase from P. marcusii that can be used for the industrial production of prebiotic oligosaccharides.
A novel acylated flavonol tetraglycoside and rare oleanane saponins with a unique acetal-linked dicarboxylic acid substituent from the xero-halophyte Bassia indica
Othman, Ahmed,Amen, Yhiya,Shimizu, Kuniyoshi
, (2021/05/17)
In recent years, the scientific interest and particularly the economic significance of halophytic plants has been highly demanding due to the medicinal and nutraceutical potential of its bioactive compounds. A xero-halophyte Bassia indica is deemed to be
Supramolecular Interaction of Molecular Cage and β-Galactosidase: Application in Enzymatic Inhibition, Drug Delivery and Antimicrobial Activity
Mondal, Avijit,Bhat, Imtiyaz Ahmad,Karunakaran, Subbaraj,De, Mrinmoy
, p. 1955 - 1960 (2021/05/04)
Enzyme inhibitors play a crucial role in diagnosis of a wide spectrum of diseases related to bacterial infections. We report here the effect of a water-soluble self-assembled PdII8 molecular cage towards β-galactosidase enzyme activity. The molecular cage is composed of a tetrapyridyl donor (L) and cis-[(en)Pd(NO3)2] (en=ethane-1,2-diamine) acceptor and it has a hydrophobic internal cavity. We have observed that the acceptor moiety mainly possesses the ability to inactivate the β-galactosidase enzyme activity. Kinetic investigation revealed the mixed mode of inhibition. This inhibition strategy was extended to control the growth of methicillin-resistant Staphylococcus aureus. The internalization of the Pd(II) cage inside the bacteria was confirmed when bacterial solutions were incubated with curcumin loaded cage. The intrinsic green fluorescence of curcumin made the bacteria glow when put under an optical microscope. Furthermore, this curcumin loaded molecular cage shows an enhanced antibacterial activity. Thus, PdII8 molecular cage is quite attractive due to its dual role as enzyme inhibitor and drug carrier.
A total of eight novel steroidal glycosides based on spirostan, furostan, pseudofurostan, and cholestane from the leaves of cestrum newellii
Iguchi, Tomoki,Mimaki, Yoshihiro,Takahashi, Naoki
, (2020/10/20)
Previously, various steroidal glycosides were reported from plants of Cestrum species. However, phytochemical investigation has not been conducted on Cestrum newellii. A systematic phytochemical investigation of the leaves of C. newellii resulted in the isolation of eight novel steroidal glycosides (1-8), which were classified into three spirostanol glycosides (1-3), two furostanol glycosides (4 and 5), two pseudofurostanol glycosides (6 and 7), and one cholestane glycoside (8). In addition, three known cholestane glycosides (9-11) were isolated and identified. The structures of the new compounds were determined based on spectroscopic data and chemical transformations. Compounds 1 and 2 are spirostanol glycosides having hydroxy groups at C-2, C-3, C-12, and C-24 of the aglycone moiety. Although C. newellii is known to be a poisonous plant, the 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyl-2H-tetrazoliumbromide assay exhibited that none of the isolated compoundswere cytotoxic to HL-60 human promyelocytic leukemia cells.
Triterpene saponins from Silene gallica collected in North-Eastern Algeria
Bechkri, Sara,Alabdul Magid, Abdulmagid,Sayagh, Charlotte,Berrehal, Djemaa,Harakat, Dominique,Voutquenne-Nazabadioko, Laurence,Kabouche, Zahia,Kabouche, Ahmed
, (2020/01/25)
Eleven previously undescribed triterpene saponins, named silenegallisaponin A-K (1–11), were isolated from the aerial parts of Silene gallica L. Their structures were elucidated by analysis of 1D and 2D-NMR spectroscopic data and mass spectrometry (HR-ESI-MS). The saponins comprised caulophyllogenin, echinocystic acid, or quillaic acid substituted at C-3 by a β-D-glucuronic acid or β-D-galactopyranosyl-(1 → 3)-β-D-glucuronopyranoside and at C-28 by a β-D-fucopyranose substituted at C-2 by a β-D-glucose and at C-3 by a β-D-glucose or a β-D-quinovose.
Structure elucidation of a novel oligosaccharide (Medalose) from camel milk
Gangwar, Lata,Singh, Rinku,Deepak, Desh
, p. 157 - 161 (2017/10/13)
Free oligosaccharides are the third most abundant solid component in milk after lactose and lipids. The study of milk oligosaccharides indicate that nutrients are not only benefits the infant's gut but also perform a number of other functions which include stimulation of growth, receptor analogues to inhibit binding of pathogens and substances that promote postnatal brain development. Surveys reveal that camel milk oligosaccharides possess varied biological activities that help in the treatment of diabetes, asthma, anaemia, piles and also a food supplement to milking mothers. In this research, camel milk was selected for its oligosaccharide contents, which was then processed by Kobata and Ginsburg method followed by the HPLC and CC techniques. Structure elucidation of isolated compound was done by the chemical degradation, chemical transformation and comparison of chemical shift of NMR data of natural and acetylated oligosaccharide structure reporter group theory, the 1H, 13C NMR, 2D-NMR (COSY, TOCSY and HSQC) techniques, and mass spectrometry. The structure was elucidated as under: MEDALOSE[Figure presented]
Online Monitoring of Enzymatic Reactions Using Time-Resolved Desorption Electrospray Ionization Mass Spectrometry
Cheng, Si,Wu, Qiuhua,Xiao, He,Chen, Hao
, p. 2338 - 2344 (2017/08/09)
Electrospray ionization mass spectrometry (ESI-MS) is powerful for determining enzymatic reaction kinetics because of its soft ionization nature. However, it is limited to use ESI-favored solvents containing volatile buffers (e.g., ammonium acetate). In addition, lack of a quenching step for online ESI-MS reaction monitoring might introduce inaccuracy, due to the possible acceleration of reaction in the sprayed microdroplets. To overcome these issues, this study presents a new approach for online measuring enzymatic reaction kinetics using desorption electrospray ionization mass spectrometry (DESI-MS). By using DESI-MS, enzymatic reaction products in a buffered aqueous media (e.g., a solution containing Tris buffer or high concentration of inorganic salts) could be directly detected. Furthermore, by adjusting the pH and solvent composition of the DESI spray, reaction can be online quenched to avoid the postionization reaction event, leading to fast and accurate measurement of kinetic constants. Reaction time control can be obtained simply by adjusting the injection flow rates of enzyme and substrate solutions. Enzymatic reactions examined in this study include hydrolysis of 2-nitrophenyl-β-D-galactopyranoside by β-galactosidase and hydrolysis of acetylcholine by acetylcholinesterase. Derived Michaelis-Menten constants Km for these two reactions were determined to be 214 μM and 172 μM, respectively, which are in good agreement with the values of 300 μM and 230 μM reported in literature, validating the DESI-MS approach. Furthermore, this time-resolved DESI-MS also allowed us to determine Km and turnover number kcat for trypsin digestion of angiotensin II (Km and kcat are determined to be 6.4 mM and 1.3 s-1, respectively).
