02241nas a2200193 4500008004100000245026500041210006900306260000800375300001200383490000600395520137300401100002701774700002001801700002001821700001701841700002201858700002601880856014101906 2020 eng d00aSimultaneous identification and estimation of glycyrrhizin, glabridin, and 18β‐glycyrrhetinic acid in de‐glycyrrhized Ayurvedic lipid‐based formulation of Glycyrrhiza glabra using dual wavelength reverse phase‐high‐performance liquid chromatography 0 aSimultaneous identification and estimation of glycyrrhizin glabr cAUG a460-4710 v33 a

Plant‐based Ayurvedic formulations such as medicated oils, confectioneries, etc. are developed with a rationale of selecting specific compounds for targeted action and minimal side effects. It is imperative to develop an analytical method to simultaneously identify and quantify the targeted compounds for good resolution with low retention time. The present assay using reverse phase‐high‐performance liquid chromatography is optimized to resolve glycyrrhizin, glabridin, and 18β‐glycyrrhetinic acid simultaneously at retention times of 6.6, 8.1, and 10.2 min, respectively, using acidified mobile phase from Glycyrrhiza glabra utilized in Ayurvedic lipid (cow's ghee and sesame oil) based formulations. Raw material, its decoction, and residues formed during preparation steps were extracted in methanol while lipid formulations were extracted using a binary solvent system of methanol and n‐hexane. The separation was performed on Hypersil gold column maintained at 40°C using 0.2% ortho‐phosphoric acid with pH 3.5 in water and acetonitrile as binary gradient mobile phase. The compounds were detected at wavelengths 230 (glabridin) and 254 (glycyrrhizin and 18β‐glycyrrhetinic acid) nm. The method revealed de‐glycyrrhized finished products containing glabridin and 18β‐glycyrrhetinic acid having medicinal value.

1 aKumbhalkar, Bhagyashri1 aWalunj, Tanhaji1 aChavan, Sandeep1 aGupta, Vidya1 aDeshmukh, Vineeta1 aSardeshmukh, Sadanand uhttps://library.ncl.res.in/content/simultaneous-identification-and-estimation-glycyrrhizin-glabridin-and-18%CE%B2%E2%80%90glycyrrhetinic02559nas a2200265 4500008004100000022001400041245014200055210006900197260000900266300001100275490000800286520163300294653002301927653002201950653003401972653002102006653002602027100002002053700002102073700001902094700002202113700001702135700002002152856012102172 2024 eng d a0006-291X00aStructure of epoxide hydrolase 2 from Mangifera indica throws light on the substrate specificity determinants of plant epoxide hydrolases0 aStructure of epoxide hydrolase 2 from Mangifera indica throws li cNOV  a1504440 v7333 a

Epoxide hydrolases (EHs) are a group of ubiquitous enzymes that catalyze hydrolysis of chemically reactive epoxides to yield corresponding dihydrodiols. Despite extensive studies on EHs from different clades, generic rules governing their substrate specificity determinants have remained elusive. Here, we present structural, biochemical and molecular dynamics simulation studies on MiEH2, a plant epoxide hydrolase from Mangifera indica. Comparative structure-function analysis of nine homologs of MiEH2, which include a few AlphaFold structural models, show that the two conserved tyrosines (MiEH2Y152 and MiEH2Y232) from the lid domain dissect substrate binding tunnel into two halves, forming substrate-binding-pocket one (BP1) and two (BP2). This compartmentalization offers diverse binding modes to their substrates, as exemplified by the binding of smaller aromatic substrates, such as styrene oxide (SO). Docking and molecular dynamics simulations reveal that the linear epoxy fatty acid substrates predominantly occupy BP1, while the aromatic substrates can bind to either BP1 or BP2. Furthermore, SO preferentially binds to BP2, by stacking against catalytically important histidine (MiEH2H297) with the conserved lid tyrosines engaging its epoxide oxygen. Residue (MiEH2L263) next to the catalytic aspartate (MiEH2D262) modulates substrate binding modes. Thus, the divergent binding modes correlate with the differential affinities of the EHs for their substrates. Furthermore, long-range dynamical coupling between the lid and core domains critically influences substrate enantioselectivity in plant EHs.

10aEnantioselectivity10aEpoxide hydrolase10amolecular dynamics simulation10aRegioselectivity10aX-ray crystallography1 aBhoite, Ashwini1 aGaur, Neeraj, K.1 aPalange, Megha1 aKontham, Ravindar1 aGupta, Vidya1 aKulkarni, Kiran uhttps://library.ncl.res.in/content/structure-epoxide-hydrolase-2-mangifera-indica-throws-light-substrate-specificity