Anti-glycating and anti-oxidant compounds from traditionally used anti-diabetic plant Geigeria alata(DC) Oliv. & Hiern.

Abstract

A new sesquiterpene lactone geigerianoloide (1) and four known flavonoids axillarin (2), quercetin (3), 3-methoxy-5,7,3',4'-tetrahydroxy-flavone (4) and hispidulin (5) were isolated from Geigeria alata (DC) Oliv. & Hiern. (Asteraceae). Structures were deduced using ¹H- and ¹³C- NMR spectroscopy, mass spectrometry, while the structure of compound 1 was also deduced using X-ray crystallography technique.

Geigeria alata is traditionally used for diabetes, therefore compounds were tested for anti-glycation activity, in which compounds 2 and 3 showed potent activities (IC₅₀ values of 246.97?±?0.83 and 262.37?±?0.22 µM, respectively) compared to IC₅₀ value 294.50?±?1.5 µM of rutin. Moreover, compound 4 exhibited a comparable activity to rutin (IC₅₀?=?293.28?±?1.34 µM). Compound 5 showed a weak activity.

Compounds 2, 3, and 4 exhibited potent DPPH radical scavenging activity (IC₅₀?=?0.1?±?0.00, 0.13?±?0.00 and 0.15?±?0.01 µM, respectively). Compounds 2, 3, and 4 demonstrated significant superoxide anion scavenging activity with IC₅₀ values of 0.14?±?0.001, 0.17?±?0.00, and 0.11?±?0.006 µM, respectively.     

MEKC determination of vanadium from mineral ore and crude petroleum oil samples using precapillary chelation with bis(salicylaldehyde)tetramethyl‐ethylenediimine

An analytical procedure has been developed for the separation of Cu(II), Ni(II), Co(II), Fe(II), Pd(II), Th(IV), V(IV), and determination of Fe(II), Co(II), Ni(II), and V(IV) by MEKC after chelation with bis(salicylaldehyde)tetramethylethylenediimine (H₂SA₂Ten). Uncoated fused silica capillary was used with an applied voltage of 30 kV with photo‐diode array detection at 228 nm. SDS was added as micellar medium at pH 8.2 with sodium tetraborate buffer (0.1 M). Linear calibrations were established within 0.015–1000 μg/mL of each element with LOD within 5–67 ng/mL. The method was applied for the determination of vanadium from crude oil and ore samples in the range 0.34–2.40 and 114.2–720.7 μg/g with RSD 1.7–3.8 and 0.98–2.30% (n = 3), respectively. Fe, Ni, and Co present in crude oil and ore samples were also determined with RSD 1.3–2.8, 1.1–4.1, and 1.2–3.5% (n = 3), respectively. The results were compared with that of supplier's specifications and atomic absorption spectrometry (AAS). Method was evaluated by standard addition technique.     

Structure determination of salisomide and salisoflavan,two new secondary metabolites from Salsola imbricata,by 1D and 2D NMR spectroscopy

Chromatographic analysis of the alcoholic extract from Salsola imbricata yielded two new secondary metabolites, salisomide (1) and salisoflavan (2). Their structures were established with the help of spectroscopic techniques including COSY, HMQC and HMBC NMR experiments. Copyright © 2008 John Wiley & Sons, Ltd.     

Two New Disulfated Triterpenoids from Zygophyllum fabago

From the aerial parts of Zygophyllum fabago, two new monosodium salts of sulfated derivatives of ursolic acid, along with two known quinovic acid glycosides were isolated. The structures of the new compounds were determined as (3β,4α)‐3,23,30‐trihydroxyurs‐20‐en‐28‐al 3,23‐di(sulfate) sodium salt (1 : 1) ( 1 ) and of (3β,4α)‐3,23,28‐trihydroxyurs‐20‐en‐30‐yl β‐D ‐glucopyranoside 3,23‐di(sulfate) sodium salt (1 : 1) ( 2 ) with the molecular formula C₃₀H₄₇NaO₁₀S₂ and C₃₆H₅₉NaO₁₅S₂, respectively. The structures of the known compounds were 3‐O‐(2‐O‐sulfo‐β‐D ‐quinovopyranosyl)quinovic acid 28‐β‐D ‐glucopyranosyl ester ( 3 ) and 3‐O‐(β‐D ‐glucopyranosyl)quinovic acid 28‐β‐D ‐glucopyranosyl ester ( 4 ) (quinovic acid=(3β)‐3‐hydroxyurs‐12‐ene‐27,28‐dioic acid). The structures of all these compounds were determined by using 1D‐ and 2D‐NMR spectroscopic techniques.     

Determination of major and trace elements in the indigenous medicinal plant Withania somnifera and their possible correlation with therapeutic activity

Withania somnifera (family Solanaceae) has been studied to determine major and trace elements and their possible correlation with therapeutic value of the plant. Nine trace elements were determined in Withania somnifera. This important medicinal plant was found to be rich in Fe, Cu, Ni, Mn, and Zn. These trace elements are well known for curing diseases. The plant contains nutrient elements, which are best sources for fodder.     

Thiol–Ene “Click” Reaction Triggered by Neutral Ionic Liquid: The “Ambiphilic” Character of [hmim]Br in the Regioselective Nucleophilic Hydrothiolation

Thiol–ene “click” chemistry has emerged as a powerful strategy to construct carbon–heteroatom (C? S) bonds, which generally results in the formation of two regioisomers. To this end, the neutral ionic liquid [hmim]Br has been explored as a solvent cum catalyst for the synthesis of linear thioethers from activated and inactivated styrene derivatives or secondary benzyl alcohols and thiols without the requirement of using a metal complex, base, or free radical initiator. Furthermore, detailed mechanistic investigations using ¹H NMR spectroscopy and quadrupole time‐of‐flight electrospray ionization mass spectrometry (Q‐TOF ESI‐MS) revealed that the “ambiphilic” character of the ionic liquid promotes the nucleophilic addition of thiol to styrene through an anti‐Markovnikov pathway. The catalyst recyclability and the extension of the methodology for thiol–yne click chemistry are additional benefits. A competitive study among thiophenol, styrene, and phenyl acetylene revealed that the rate of reaction is in the order of thiol–yne>thiol–ene>dimerization of thiol in [hmim]Br.     

Rapid preparative isolation of erythrocentaurin from Enicostemma littorale by medium‐pressure liquid chromatography,its estimation by high‐pressure thin‐layer chromatography,and its α‐amylase inhibitory activity

Erythrocentaurin is a relatively simple natural product present among the members of Gentianaceae. A preparative method for the isolation of erythrocentaurin from the ethyl acetate fraction of Enicostemma littorale using medium‐pressure liquid chromatography has been reported. The method consisted of a simple step gradient from 10 to 20% ethyl acetate in n‐hexane. Using a 70 × 460 mm Si60 column, this method is capable of processing 20 g of material in <3 h (purity ≈ 97%). The recovery of erythrocentaurin was 87.77%. Estimation of erythrocentaurin in extracts and fractions based on high‐pressure thin‐layer chromatography was carried out on silica gel 60 F₂₅₄ plates with toluene/ethyl acetate/formic acid (80:18:2 v/v/v) as the mobile phase. The densitometric analysis was performed at 230 nm. A well‐separated compact band of erythrocentaurin appeared at R_f 0.54 ± 0.04. The analytical method showed good linearity in the concentration range of 200–1500 ng/band with a correlation coefficient of 0.99417. The limits of detection and quantification were found to be ≈60 and ≈180 ng/band, respectively. Erythrocentaurin exhibited a concentration‐dependent α‐amylase inhibition (IC₅₀ 1.67 ± 0.28 mg/mL). The outcome of the study should be considered for pharmacokinetic and biotransformation studies involving E. littorale.     

Efficient bifunctional gallium-68 chelators for positron emission tomography: tris(hydroxypyridinone) ligands

A new tripodal tris(hydroxypyridinone) bifunctional chelator for gallium allows easy production of (68)Ga-labelled proteins rapidly under mild conditions in high yields at exceptionally high specific activity and low concentration.     

Transfer of radioactivity from soil to vegetation in Rechna Doab, Pakistan

In Rechna Doab, samples of the most common vegetation, perennial grass Desmostachya bipinnata (dab), were collected along with soil samples from 29 sites. Natural radioactivity of 22?Ra, 232Th/22?Ac and ??K was measured by using high purity germanium-based gamma ray spectrometer. Activity concentration levels of 22?Ra, 232Th/22?Ac and ??K in soil were found to be 46.8 ± 6.2 (36.0-57.6), 61.4 ± 5.9 (48.2-73.2) and 644.8 ± 73.9 (537.7-868.4) Bq kg?1 (dry mass), respectively, and those in vegetation were 2.74 ± 1.70 (1.00-6.39), 2.24 ± 0.59 (1.56-2.61) and 172.72±113.37 (53.14-469.24) Bq kg?1 (dry mass), respectively. The measured values of the activity concentration in vegetation are comparable with some other international data. Calculated soil to vegetation transfer factors of 22?Ra, 22?Ac and ??K were 0.06 ± 0.03 (0.02-0.14), 0.04 ± 0.01 (0.03-0.04) and 0.26 ± 0.16 (0.09-0.69). The mean outdoor absorbed dose rate in air for the area under study was determined as 8.22 nGy h?1 and the mean indoor absorbed dose rate in air was 11.52 nGy h?1. The total annual effective dose to the general public from the vegetation was found to be (0.02-0.16) mSv, which is below the recommended limit value of 1 mSv y?1 for the general public. The dab vegetation under study was found to be radiologically safe for the population and environment.