Discrimination of Scrophularia spp. according to geographic origin with HPLC-DAD combined with multivariate analysis

Discrimination of Scrophularia spp. according to the geographic origin was tried in the present study using HPLC-DAD combined with multivariate analysis techniques. Five active constituents, angoroside C, harpagoside, 8-O-(E-p-methoxycinnamoyl)harpagide, E-cinnamic acid and E-p-methoxycinnamic acid, in forty four Scrophularia samples were simultaneously determined using HPLC-DAD. A principal component analysis of the content measurements clustered the samples according to their geographic origins, Andong, Uisung and China. A partial least squares-discrimination analysis was subsequently developed for the effective classification of the samples. This model showed comparatively good prediction ability for samples from Andong or China. The proposed method shows an efficient strategy for quality control of Scrophularia spp.     

Simultaneous determination of four active constituents in the roots of Scrophularia buergeriana by HPLC-DAD and LC-ESI-MS

The chemical profile of four main bioactive constituents including harpagoside (HS), 8-O-(E-p-methoxycinnamoyl)harpagide (HG), E-cinnamic acid (CA), and E-p-methoxycinnamic acid (MCA), in the extract of Scrophularia buergeriana was studied using HPLC-diode array detector-electrospray-MS (HPLC-DAD-ESI-MS). The HPLC-DAD conditions were optimized for the simultaneous analysis of these four compounds. This method was validated in terms of specificity, linearity (r(2) >0.9998), precision (< 2.0% RSD), and recoveries (94.4-115.1%). The LOD of these compounds were ranged from 5.9 to 37.8 ng. In addition, the main compounds in S. buergeriana and S. ningpoensis were quantified using this validated method, which resulted in significant difference in the contents of these compounds between the species.     

Application of near infrared spectroscopy (NIR), X-ray fluorescence (XRF) and chemometrics to the differentiation of marmora samples from the Mediterranean basin

Abstract

Near-infrared (NIR) and X-ray fluorescence spectra were recorded for 15 different samples of marmora, from the Mediterranean Basin and of different colours. After appropriate pretreatment (SNV transform + second derivative), the results were subjected to principal component analysis (PCA) treatment with a view to differentiating them. The observed differences among the samples were chemically interpreted by highlighting the NIR wavelengths and minerals, respectively, contributing the most to the PCA models. Moreover, a mid-level data fusion protocol allowed integrating the information from the different techniques and, in particular, to correctly identify (based on the distance in the score space) three test samples of known type. Moreover, it should be stressed that positive results on the differentiation and identification of marmora were obtained using two completely non-invasive, non-destructive and relatively inexpensive techniques, which can also be used in situ.     

Improved multivariate calibration models for corn stover feedstock and dilute-acid pretreated corn stover

We have studied rapid calibration models to predict the composition of a variety of biomass feedstocks by correlating near-infrared (NIR) spectroscopic data to compositional data produced using traditional wet chemical analysis techniques. The rapid calibration models are developed using multivariate statistical analysis of the spectroscopic and wet chemical data. This work discusses the latest versions of the NIR calibration models for corn stover feedstock and dilute-acid pretreated corn stover. Measures of the calibration precision and uncertainty are presented. No statistically significant differences (p = 0.05) are seen between NIR calibration models built using different mathematical pretreatments. Finally, two common algorithms for building NIR calibration models are compared; no statistically significant differences (p = 0.05) are seen for the major constituents glucan, xylan, and lignin, but the algorithms did produce different predictions for total extractives. A single calibration model combining the corn stover feedstock and dilute-acid pretreated corn stover samples gave less satisfactory predictions than the separate models.     

Evaluation of in vivo analgesic activity of Scrophularia kotscyhana and isolation of bioactive compounds through activity-guided fractionation

The present study was undertaken to evaluate the in vivo analgesic activities of the extracts prepared from the aerial parts and roots of Scrophularia kotscyhana and to isolate the bioactive metabolites from the most active extract. Analgesic activities of all extracts and subextracts at the doses of 5, 10 and 30 mg/kg (i.p.) were examined using hot plate test in mice. Among the tested extracts, MeOH extract prepared from the aerial parts and the n-butanol subextract prepared thereof displayed the best analgesic activity at all doses. Phytochemical studies on n-butanol subextract led to the isolation of two new iridoid glycosides as an inseparable mixture, 8-O-acetyl-4′-O-(E)-(p-coumaroyl)-harpagide (1) and 8-O-acetyl-4′-O-(Z)-(p-coumaroyl)-harpagide (2) along with five known secondary metabolites, β-sitosterol 3-O-β-glucopyranoside (3), apigenin 7-O-β-glucopyranoside (4), apigenin 7-O-rutinoside (5), luteolin 7-O-β-glucopyranoside (6) and luteolin 7-O-rutinoside (7). The iridoid mixture (1 and 2), 3 and 4 elicited significant inhibition of pain at 5 mg/kg dose.     

Analysis of Methylcitric Acid by Enantioselective Multidimensional Gas Chromatography-Mass Spectrometry

Methylcitric acid (2-hydroxybutane-1,2,3-tricarboxylic acid–MCA) is a structural analogue of citric acid, but due to an additional methyl group it is a chiral molecule with two stereogenic centers and thus four stereoisomers are conceivable. MCA occurs naturally as prominent metabolite in body fluids of patients with inherited metabolic diseases such as propionic acidemia, methylmalonic aciduria, or holocarboxylase synthetase deficiency. Therefore methylcitric acid is considered to be an important diagnostic marker for these diseases. MCA is most likely produced from accumulated propionyl-CoA in these diseases by the enzyme si-citrate synthase from the citric acid cycle; however, there are other enzymes known which could catalyze the same reaction with different stereoselectivity, such as re-citrate synthase or the more specific enzyme methylcitrate synthase, found in microorganisms. Almost all methods dealing with MCA in the literature are non-enantioselective. For that reason there is no information about occurrence of MCA enantiomers in healthy people, patients with propionic acidemia, methylmalonic aciduria, or holocarboxylase synthetase deficiency and about value of enantiomeric distribution for diagnosis and long-term treatment. The enantioselective analysis of MCA as corresponding trimethyl ester was achieved by enantioselective multidimensional gas chromatography coupled with mass spectrometry using heptakis-(2,3-di-O-methyl-6-O-tert-butyl-dimethylsilyl)-β-cyclodextrin as chiral stationary phase. The described method allows a reliable screening of MCA in complex matrices like urine without time consuming sample preparation and with mass selective detection. During this investigation urine samples from various patients and healthy controls were analyzed. As concluded, MCA is a good diagnostic marker and can be easily measured by the method presented. Only the two stereoisomers (2S,3R) and (2S,3S) were detectable in patients and healthy controls. The varying ratios of these stereoisomers cannot presently be correlated with the health status of patients, although there are some indications that this might be possible. However, the quantitative levels of MCA, determined as the ratio of MCA absolute peak area divided by 1,000 to the creatinine contents of urine samples in this investigation, showed a dependence on the state of health and MCA would thus also be a possible marker for long-term treatment. Such a substance is of major interest nowadays since there are different studies searching for such a long-term marker in propionic acidemia or methylmalonic aciduria.     

Synthesis and characterization of double hydrophilic block copolymers containing semi-rigid and flexible segments

3-Methyl-(E)-stilbene (3MSti) and 4-(diethylamino)-(E)-stilbene (DEASti) monomers are synthesized and polymerized separately with maleic anhydride (MAn) in a strictly alternating fashion using reversible addition-fragmentation chain transfer (RAFT) polymerization techniques. The optimal RAFT chain transfer agents (CTAs) for each copolymerization affect the reaction kinetics and CTA compatibilities. Psuedo-first order polymerization kinetics are demonstrated for the synthesis of poly((3-methyl-(E)-stilbene)-alt-maleic anhydride) (3MSti-alt-MAn) with a thiocarbonylthio CTA (methyl 2-(dodecylthiocarbonothioylthio)−2-methylpropionate, TTCMe). In contrast, a dithioester CTA (cumyl dithiobenzoate, CDB) controls the synthesis of poly((4-(diethylamino)-(E)-stilbene)-alt-maleic anhydride) (DEASti-alt-MAn) with pseudo-first order polymerization kinetics. DEASti-alt-MAn is chain extended with 4-acryloylmorpholine (ACMO) to synthesize diblock copolymers and subsequently converted to a double hydrophilic polyampholyte block copolymers (poly((4-(diethylamino)-(E)-stilbene)-alt-maleic acid))-b-acryloylmorpholine) (DEASti-alt-MA)-b-ACMO) via acid hydrolysis. The isoelectric point and dissociation behavior of these maleic acid-containing copolymers are determined using ζ-potential and acid–base titrations, respectively. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 219–227     

Composition of the essential oil of Geocaryum cynapioides (Guss.) L. Engstrand

Volatile constituents from two fresh samples of the subendemic Geocaryum cynapioides (Guss.) L. Engstrand (Apiaceae) obtained by hydrodistillation were analyzed by GC and GC-MS. Forty four and one hundred-twenty three constituents identified in the oils accounted for 98.7 % and 98.4 % of the total oils, respectively. The major component of both oils was (E)-β-farnesene (73.3 % and 57.7 %) while the other major contributors were: (E,E)-α-farnesene (4.8 % and 14.6 %) and trans-sesquisabinene hydrate (12.2 % and 3.0 %). The constituents endo-fenchyl acetate, and three sesquiterpene lactones belonging to the selinane (callitrisin) and guaiane (grilactone and jalcaguaianolide) series, with a rather restricted natural occurrence, were present in only one of the samples (4.7 %, trace amount, 0.1 %, 0.5 %, respectively) and completely absent from the other distinguishing so the two samples. A chemotaxonomic discussion of the results is presented.     

E,E-α-Farnesene rich essential oil of Saraca asoca (Roxb.) Wilde flower

Saraca asoca (Roxb.) Wilde (Fabaceae) commonly known as ‘Ashoka’ is a highly valued medicinal plant categorised ‘vulnerable’ by International Union for Conservation of Nature. The hydro-distilled essential oil from the flowers of S. asoca was investigated using gas chromatography equipped with a flame ionisation detector (GC-FID) and gas chromatography coupled with a mass spectrometry (GC/MS). Twenty-eight compounds representing 95.8% of the total oil were identified. The major constituents of the essential oil were E,E-α-farnesene (41.2%), hexadecanoic acid (15.3%), methyl salicylate (9.5%) and Z-lanceol (6.6%). The oil was found to be rich in sesquiterpene hydrocarbon-type constituents.     

Sesquiterpenoids from Costus Root Oil (Saussurea lappa CLARKE)

Apart from the well-known constituents (+)-β-selinene ( 2 ), (?)-β-elemene ( 4 ), (+)-β-costol ( 7 ), (?)-caryophyllene ( 17 ), and (?)-elemol ( 19 ) the following sesquiterpenoids have been isolated for the first time from costus root oil (Saussurea lappa CLARKE ): (?)-α-selinene ( 1 ), (+)-selina-4, 11-diene ( 3 ), (?)-α-trans-bergamotene ( 5 ), (?)-α-costol ( 6 ), (+)-γ-costol ( 8 ), (?)-elema-1,3,11 (13)-trien-12-ol ( 9 ), (?)-α-costal ( 11 ), (+)-γ-costal ( 12 ), (+)-γ-costal ( 13 ), (?)-elema-1,3,11 (13)-trien-12-al (elemenal, 14 ), (?)-(E)-trans-bergamota-2, 12-dien-14-al ( 15 ), (?)-ar-curcumene ( 16 ), and (?)-caryophyllene oxide ( 18 ). Compounds 6 , 8 , 9 , and 13 are new sesquiterpenoids. IR. and NMR. spectra of 12 sesquiterpenoids are reproduced.     

The synthesis and characterization of ( E,E )-dioxime and its transition metal complexes containing 12-membered macrocycles linked to ferrocenyl-methyl groups

13,14-bis(Hydroxyimino)-4,7-bis(ferrocenylmethyl)-2,3,4,5,6,7,8,9-octahydrobenzo[k]-4, 7-diaza-1,10-dithiacyclododecine[13,14-g]-quinoxaline (H₂L) has been prepared from (E,E)-dichloroglyoxime and 12,13-diamino-4,7-bis(ferrocenylmethyl)-2,3,4,5,6,7,8,9-octahydrobenzo[k]-4,7-diaza-1,10-dithiacyclododecine which was synthesized from 12,13-dinitro-4,7-bis(ferrocenylmethyl)-2,3,4,5,6,7,8,9-octahydrobenzo[k]4,7-diaza-1,10-dithia cyclododecine. Mononuclear nickel(II) and copper(II) complexes of H₂L have a metal-ligand ratio of 1?:?2 and the ligand coordinates through two nitrogen atoms, as do most (E,E)-dioximes. The homotrinuclear [Cu(L)₂Cu₂(dipy)₂](NO₃)₂ compound coordinates to the other two copper(II) ions through deprotonated oximate oxygens and two 2,2′-dipyridyl as an end-cap ligand to yield the trinuclear structure. The ligand and its complexes have been characterized on the basis of ¹H, ¹³C NMR, IR and MS spectroscopy and elemental analyses.     

Quality Evaluation of Ephedrae herba by near Infrared Spectroscopy

ABSTRACT

A novel method was developed for the quality control of Ephedrae herba by near-infrared (NIR) spectroscopy. First, qualitative models established by discriminant analysis and support vector machine were used for the preliminary screening of unqualified samples of E. herba. Then quantitative models of ephedrine and the total alkali (ephedrine and pseudoephedrine) were established by partial least squares regression and particle swarm optimization based least square support vector machine. The contents of test samples were predicted by the established NIR quantitative models. As a result, the accuracies of unqualified identification were 98.9% by discriminant analysis and 100% by support vector machine. The performance of the particle swarm optimization based least square support vector machine models were better than the partial least squares regression models. The correlation coefficients were both more than 0.98 and relative standard errors of calibrations were less than 9% in the calibration sets of particle swarm optimization based least square support vector machine models. As for the test sets, the correlation coefficients were both more than 0.93 and the relative standard errors of prediction were less than 13%, indicating satisfactory predicted results. All of these results demonstrated that NIR spectroscopy may be a powerful tool for the quality control of E. herba.     

Chemical constituents from the leaves of <Emphasis Type="Italic">Cinnamomum reticulatum</Emphasis>

Reticuol, a novel Cinnamomum sesquiterpenoid, has been isolated from Cinnamomum reticulatum Hay (Lauraceae), together with eight known compounds, p-hydroxybenzoic acid, isoanwulignan, 2,6-dimethyl1,7-octadiene-3,6-diol, a-tocopheryl quinone, kaempferol-3-O-(2″,4″-di-E-p-coumaroyl)-α-L-rhamnopyranoside, kaempferol-3-O-(3″,4″-di-E-p-coumaroyl)-α-L-rhamnopyranoside, pheophorbide a, and aristophyll C. The structure of reticuol was determined on the basis of spectroscopic analysis.     

Investigation of the Addition of Benzenethiol to p-Chlorophenylphenylacetylene

The addition of benzenethiol to p-chlorophenylphenylacetylene results in the formation of a mixture of two pairs of diastereomeric (E)- and (Z)-1-p-chlorophenyl-2-phenyl-1-phenylthioethylenes (1 and 2) and (E)- and (Z)-1-p-chlorophenyl-2-phenyl-2-phenylthioethylenes (3 and 4). The configurations of these compounds have been established by ¹ H NMR studies, by their preparation from benzyl p-chlorophenyl ketone and p-chloro-benzylphenyl ketone, and by the oxidation of the thioethylenes 1, 2, 3, and 4 to the corresponding sulphonylethylenes 5, 6, 7, and 8, respectively.     

Preparative isolation and purification of anthocyanins from purple sweet potato by high-speed counter-current chromatography

High-speed counter-current chromatography (HSCCC) was applied to the preparative isolation and purification of peonidin 3-O-(6-O-(E)-caffeoyl-2-O-β-D -glucopyranosyl-β-D -glucopyranoside)-5-O-β-D -glucoside ( 1 ), cyanidin 3-O-(6-O-p-coumaroyl)-β-D -glucopyranoside ( 2 ), peonidin 3-O-(2-O-(6-O-(E)-caffeoyl-β-D -glucopyranosyl)-6-O-(E)-caffeoyl-β-D -glucopyranoside)-5-O-β-D -glucopyranoside ( 3 ), peonidin 3-O-(2-O-(6-O-(E)-feruloyl-β-D -glucopyranosyl)-6-O-(E)-caffeoyl-β-D -glucopyranoside)-5-O-β-D -glucopyranoside ( 4 ) from purple sweet potato. Separation of crude extracts (200 mg) from the roots of purple sweet potato using methyl tert-butyl ether/n-butanol/acetonitrile/water/trifluoroacetic acid (1:4:1:5:0.01, v/v) as the two-phase solvent system yielded 1 (15 mg), 2 (7 mg), 3 (10 mg), and 4 (12 mg). The purities of 1 – 4 were 95.5%, 95.0%, 97.8%, and 96.3%, respectively, as determined by HPLC. Compound 2 was isolated from purple sweet potato for the first time. The chemical structures of these components were identified by ¹H NMR, ¹³C NMR and ESI-MSⁿ.     

近红外光谱法快速测定涂料固化剂中游离甲苯二异氰酸酯含量

用气相色谱分析值为参照,采用近红外透射光谱（NIR）技术采集相应样品的NIR光谱,研究了涂料固化剂中游离甲苯二异氰酸酯（TDI）含量的快速测定分析方法。 并从120个固化剂样品中挑选出109个代表性的样品建模,选择7320~7250 cm-1和8485~8370 cm-1波段区间,用偏最小二乘法(PLS)和完全交互验证方式建立TDI含量的预测模型。 结果表明,固化剂中游离甲苯二异氰酸酯含量和近红外光谱之间存在较好的相关性,其预测模型的校正集均方差（RMSEC）为0.0815,验证集均方差（RMSEP）为0.0715,模型性能良好。 近红外光谱法可快速准确测定游离甲苯二异氰酸酯（TDI）含量,用于固化剂样品快速分析。     

A Near-Infrared Dye That Undergoes Multiple Interconversions through Acid–Base Equilibrium and Reversible Redox Processes

A near-infrared (NIR) polymethine dye ( 1 ), consisting of a cyclohepta[1,2-b;4,3-b′]dithiophene and two phenol moieties, was synthesized. This dye exhibited pH-responsive changes in its photophysical properties due to a two-step acid–base equilibrium that produced a protonated cation ( 1H⁺ ) and an anion ( 1⁻ ). While 1H⁺ showed an intense fluorescence in the red region of the visible spectrum, 1⁻ exhibited a strong absorption in the NIR region. The tropylium ion character in 1H⁺ induces high pK_a1 and pK_a2 values for 1 . Moreover, a stable radical ( 1^. ) was prepared, which showed a NIR absorption band with a maximum at circa 1600 nm. The cyclic voltammogram of 1^. revealed a two-step reversible redox process that produced 1⁻ and the cation 1⁺ , which is different from 1H⁺ . These redox processes accompany drastic electrochromic changes in the vis–NIR region. Overall, 1 is susceptible to multiple interconversions between five forms, due to the multifaceted character of the cycloheptadithiophene skeleton.     

Characterization ofC-glycosylflavones fromDissotis rotundifolia by liquid chromatography — UV diode array detection — tandem mass spectrometry

Summary By high-performance liquid chromatography (HPLC) coupled with UV diode-array detection (DAD) and thermospray mass spectrometry (TSP-MS), four main constituents of a polar, whole plant extract fromDissotis rotundifolia T. were characterized. The fourC-glycosylflavones, isoorientin, orientin, vitexin and isovitexin were detected in the methanolic and hydroalcoholic extract of the plant as well as in the commercial drug preparation ‘Sirop de Dissotis’. Although the UV data and TSP mass spectra allowed rapid characterisation of all fourC-glycosylflavones, exact attribution of the peaks to their structures could not be achieved as neither the UV spectra nor the TSP mass spectra enabled differentiation of one position isomer from the other. Therefore a successful attempt was made to distinguish the 6-C from the 8-C-glycosylflavones by thermospray tandem mass spectrometry (TSP-MS-MS). The collision induced dissociation (CID) spectra of the particular ion [M+H-120]⁺ gave fragments which permitted differentiation of position isomers. To confirm the accuracy of on-line results, reference compounds were included in the HPLC study.     

An optical, EPR and electrical conductivity study of blue barium titanate, BaTiO3−δ

The electronic UV–VIS–NIR absorption spectra of single crystalline BaTiO_3−δ (BTO) are studied in the temperature range of 102–1173 K in pure oxygen and at conditions of moderate and strong reduction of the material. The strongly reduced crystals are of deep blue colour. The optical spectra of blue BTO are characterised by a strong absorption in the NIR region at around 7000 cm⁻¹, which is attributed to polaronic defects associated with the formation of Ti³⁺ in the material. This assumption is supported by fits of the spectra using polaronic line shape functions appropriate for disordered systems and also by the electrical conductivity of blue BTO which, in agreement with results from the optical spectra, exhibits an activation energy of 0.20 eV. The EPR spectra of moderately reduced BTO powders show an anisotropic g-factor, which is compatible with the optical spectrum. The temperature dependence of the band gap energy of BTO was found to be given as dE_g/dT = −7.21 × 10⁻⁴ eV/K.     

Intramolecular charge transfer complexes. 16. Copolymers of N,N-dimethyl-p-aminobenzyl methacrylate with acryloyl- and methacryloyl-β-hydroxyethyl-3,5-dinitrobenzoate

A new electronodonor monomer, N,N-dimethyl-p-aminobenzyl methacrylate (DMABM), was synthesized and radical copolymerized with two electronoacceptor monomers, acryloyl- (DNBA) and methacryloyl-(DNBM) β-hydroxyethyl-3,5-dinitrobenzoate, in order to obtain intramolecular charge-transfer-complex copolymers. Also, the small-molecular models of poly(DMABM), poly(DNBA), and poly(DNBM), the respective acetates, were synthesized and used to measure the values of ionization potential I_p of the donor and the electronic affinity E_a of the acceptor. They are I_p = 7.15 eV and E_a = 1.41 eV. The lower value of I_p as compared with that of carbazole derivatives is taken as evidence of a nonterminal mechanism of copolymerization. Also, from the ¹H-NMR and electronic spectra, the intramolecular complexation is discussed in terms of total transfer of the electron from donor to acceptor structural units.