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In this study, the thermal stability of phospholipids (PLs) extracted from coffee beans was investigated. Chemical analysis was used to obtain information about the effect of heat treatment on the content of PLs in roasted coffee beans. Normal phase high-performance liquid chromatography (HPLC) combined with evaporative light scattering detector (ELSD) was applied to identify and quantify the classes of PLs. The results showed that only two PLs (phosphatidylinositol (PI), and phosphatidylcholine (PC)) were detected in coffee. One gram total lipid of green coffee contained 7.79 mg of PI, 9.6 mg of PC. As the duration of heat treatment was increased, there was a decrease in the content of PI and PC. With increases in temperature at various durations, the content of PI and PC was significantly decreased. Moreover, PI has been found to be more thermo sensitive than PC.

The suitability of online liquid chromatography-gas chromatography for the analysis of free sterols/stanols, steryl/stanyl fatty acid esters, and trans-steryl/stanyl ferulic acid esters in cereals is demonstrated. The silylated lipid extracts were fractionated via liquid chromatography on a normal phase, and the fractions containing the sterol classes were transferred online to the gas chromatograph for the analysis of their individual compositions. The study provides for the first time data on free sterols/stanols and intact steryl/stanyl esters in sweet corn, popcorn, and proso millet. Sweet corn revealed the highest contents of free sterols/stanols and steryl/stanyl fatty acid esters, and popcorn, in turn, the highest amounts of trans-steryl/stanyl ferulic acid esters. The distribution patterns of the proso millet samples revealed pronounced differences from those of sweet corn and popcorn as they particularly exhibited high proportions of free cholesterol and cholesteryl fatty acid esters. Furthermore, no trans-steryl/stanyl ferulic acid esters could be detected.

A scheme for industrial preparative chromatography purification of 10-deacetylpaclitaxel (10-DAP), the semi-synthesized precursor of anticancer drug paclitaxel was developed. 7-Xylosyl-10-deacetylpaclitaxel (10-DAXP) is the most abundant constitute in the needles of Taxus Chinensis, a specific yew species distributed in China. 10-DAXP has been recognized as a good material to convert into 10-DAP, the most ideal precursor of paclitaxel. The partially purified extract from yew needles which mainly contains 10-DAXP (> 60%) and other two minor 7-xylosyl-10-deacetyltaxanes including 7-xylosyl-10-deacetylcephalomannine (10-DAXC) and 7-xylosyl-10-deacetylpaclitaxel C (10-DAXP C), was used as the starting material. The total scheme can be divided into four steps. Firstly, the starting material was hydrolyzed by beta-xylosidase to remove the C-7 xylosyl group completely; and then the hydrolyzed products mainly containing 10-DAP were eluted on a column packed with resin to get crude 10-DAP (with the purity of 20.5%) with high yield (96.3%). The crude 10-DAP was purified by a column packed with normal phase, and then by a reversed-phase preparative chromatography with ODS as the solid phase. After these two steps, the purity of the aim product 10-DAP was 96% with the overall yield of 79.7%. This novel scheme was suitable for large-scale purification of 10-DAP from 10-DAXP.

γ-Oryzanol is an important phytochemical used in pharmaceutical, alimentary and cosmetic preparations. The present article, for the first time, discloses the performances of NP-HPLC in separating γ-oryzanol components and develops a validated method for its routine quantification. The analysis is performed on a cyanopropyl bonded column using the hexane/MTBE gradient elution and UV detection at 325 nm. The method allows: the separation of steryl ferulate, p-coumarate and caffeate esters, the separation of cis- from trans-ferulate isomers, the splitting of steroid moieties into saturated and unsaturated at the side chain. The optimised method provides excellent linear response (R(2)=0.99997), high precision (RSD

Qualitative and quantitative methods for the analysis of intact phytosteryl/phytostanyl esters in enriched dairy products with substantial amounts of protein and fat were established. Lipids were extracted after acid digestion in order to achieve a complete extraction of the esters. The extracted lipids were separated via liquid chromatography on a normal phase, and the fraction containing the phytosteryl/phytostanyl esters was subsequently transferred on-line and analyzed by means of capillary gas chromatography. The applicability of the method was demonstrated for the analysis of intact phytosteryl/phytostanyl fatty acid esters in enriched yogurt, cheese-based spread, and milk. The approach enables the determination of individual phytosteryl/phytostanyl esters as well as of their total contents and provides detailed information on the distributions of esterified phytosterols/phytostanols and fatty acids. The employed approach complements the existing GC-based methods for the analysis of phytosteryl/phytostanyl esters in low-fat and fat-based products and thus creates a base for authenticity assessments of these types of novel foods.

We present a video-densitometric quantification method for benzocaine in lozenges. The quantification is based on a derivatisation reaction with 4-dimethylaminobenzaldehyde. Measurements were carried out using a 16-bit flatbed scanner. Benzocaine was separated to a distance of 50 mm in a vertical developing chamber without vapour saturation. We present an RP-18 phase separation on a cyanopropyl plate (Merck, Darmstadt, Germany) using water, CH3CN, dioxane, ethanol, and NH3 (25 %) (8 + 2 + 1 + 1 + 0.05, v/v) as the mobile phase. We also separated benzocaine in a normal phase system on silica gel 60 LiChrospere® plates (Merck, Darmstadt, Germany) with the mobile phase MTBE/cyclohexane (1 + 1, v/v). The calibration functions for benzocaine in both separations were linear in the range from 1 to 1,000 ng per spot. The range of linearity covers two magnitudes of power because the Kubelka–Munk expression was used for data transformation. In the cyanopropyl-system, the benzocaine amount was quantified as 242.5 ± 18.2 ng in a spot or 6.86 ± 0.52 mg in a single lozenge. The amount of 7.0 mg benzocaine per lozenge was labelled. The combined uncertainty of sample and calibration measurements was statistically calculated using a significance level of α = 0.05 to a total relative uncertainty of 7.49 %. The separation method is inexpensive, fast and reliable.

This paper describes the development of a normal-phase liquid chromatography ultraviolet‐diode array detection method for the simultaneous quantification of parthenin and coronopilin in the leaves and flowers of Parthenium hysterophorous. The compounds were analyzed on a Merck Si60 silica column (5 mm, 250 3 4 mm) using an isocratic 15:85 mixture of isopropyl alcohol and hexane. The calibration curves resulting from the reference compounds in the concentration range of 200‐2,000 ng exhibited acceptable linearity (r > 0.999). The method was developed to study the levels of parthenin and coronopilin in the leaves and flowers of P. hysterophorous collected during different seasons, and the method was validated by analyzing the spiked samples.

In this study of the recovery and purification of rapamycin from the culture broth of an actinomycetes strain MTCC 5681, we investigated various factors such as biomass separation, suitable solvents for extraction, normal phase and flash chromatographic conditions and selective precipitation to obtain rapamycin in substantially pure form of the product. Adsorption chromatography particularly with normal phase and flash chromatography, in combination with centrifugal decantation is found to be the most suitable for separation as well as purification of rapamycin. Centrifugal decantation technique is likely to emerge as an efficient, industrially scalable, high yielding and economical process for biomass separation. The purity of rapamycin obtained through the method described was 99.4% which has not been reported so far.

A new simple isocratic chiral liquid chromatographic method was developed for the enantiomeric purity of Ramelteon[( S )- N -[2-(1,6,7,8-tetrahydro-2 H -indeno[5,4-b]furan-8-yl) ethyl]-propionamide], a melatonin agonist in bulk drugs. The chromatographic separation was achieved on Chiralpak AD-H, 250 mm × 4.6 mm, 5 μm column using a mobile phase system consisting of n -hexane, ethanol and methanesulfonic acid in the ratio of 900:100:0.1 (v/v/v). The mobile phase was pumped on the column at the flow rate of 1 mL min −1 . Addition of methane sulfonic acid in the mobile phase enhanced chromatographic efficiency and resolution between the enantiomers. The resolution between the enantiomers was found to be more than four. The developed method was subsequently validated and proved to be accurate and precise. The experimentally established limit of detection and quantification of ( R )-enantiomer were found to be 25.5 and 77.2 ng ml −1 , respectively, for 20 μl injection volumes. The percentage recovery of ( R )-enantiomer was ranged from 98.5 to 101.9 in bulk drug samples of Ramelteon. The stability of Ramelteon sample in analytical solution was checked for about 48 h at room temperature and was found to be stable for about 48 h. The proposed method was found to be suitable and accurate for the quantitative determination of ( R )-enantiomer in drug substance.

In this study, the recently developed type of chiral stationary phase, R-naphthylethyl-derivatized cyclofructan 6 (RN-CF6) was used for direct enantioseparation of novel chiral analogs of spiroindoline phytoalexins with potential anticancer and antimicrobial activity using HPLC. The experiments were performed under normal phase elution. Effects of polar modifier, the structure of the analytes and temperature on the separation were investigated. The thermodynamic parameters were evaluated from van’t Hoff plots. Cyclofructan-based chiral stationary phase, RN-CF6, was able to separate all eighteen racemic mixtures of studied phytoalexins including cis- and trans-diastereoisomers.

A simple and rapid Supercritical Fluid Chromatography (SFC) method has been developed to isolate and characterize R-Isomer of Ezetimi be by using normal phase Chiral Cel OD-H with 250 mm × 30 mm, 5 microns column using a mobile phase system containing super critical fluid carbondi oxide (Co2) and the percentage of 2-Propanol as a mobile phase (85:15) and detection at 230 nm. The isolated R-Isomer is characterized by using UV-vis, FT-IR, ESI-MS, HPLC1H and 13C NMR. The purity of isolated R-Isomer is about 98%.

Currently, acrylamide concentration in processed food products have become a very serious health issue. The World Health Organization (WHO) and the Scientific Committee for Food (SCF) of the European Union also confirmed this concern. In laboratory scale, it was found that acrylamide causes tumors in animals. This study is aimed to determine the concentration of acrylamide in processed food products available in open market. In order to determine the acrylamide concentration, three bakery items and three fried chips from three different brands were analyzed. High-performance liquid chromatography (HPLC) technique was employed for the analysis. The overall distribution of crylamide concentration was found to be maximum in kurkure followed by lays and minimum in banana Chips. Key words : Processed food, high-performance liquid chromatography, acrylamide, health hazard.

PSR B0919+06 generally radiates radio pulses in a normal phase range. It has been known for its occasional perplexing abnormal emission events wherein individual pulses come to an earlier phase range for a few tens of periods and then returns to its usual phase. Heretofore, only a few such events have been available for study. We observed PSR B0919+06 for about 30 hours using the Jiamusi 66-m telescope at Jiamusi Deep Space Station at S-band, and detected 92 abnormal emission events. We identify four types of events based on the abrupted or gradual phase-shifting of individual pulses. The abnormal emission events are seen to occur randomly some every 1000 to 3000 periods, and they affect the leading edge of the mean profile by up to 2\% in amplitude. The abnormal emission events are probably related to gradual changes of emission processing in the pulsar magnetosphere., 9 pages, 13 figures. MNRAS Published

Following a methodology similar to \cite{Alishahiha:2015rta}, we derive a holographic complexity for two dimensional holographic superconductors (gauge/string superconductors) with backreactions. Applying a perturbation method proposed by Kanno in Ref. \cite{kanno}, we study behaviors of the complexity for a dual quantum system near critical points. We show that when a system moves from the normal phase ($T>T_c$) to the superconductor phase ($T, Comment: 6 pages

A superconductor in a magnetic field has surface currents that prevent the magnetic field from penetrating its interior. These currents carry kinetic energy and mechanical momentum. When the temperature is raised and the system becomes normal the currents disappear. Where do the kinetic energy and mechanical momentum of the currents go, and how? Here we propose that the answer to this question reveals a key necessary condition for materials to be superconductors, that is not part of conventional BCS-London theory: superconducting materials need to have hole carriers., Comment: Does not meet the Physical Review Letters criteria of impact, innovation, and interest according to Editor Dr. Hebboul

Astringency perception, as an essential parameter for high-quality red wine, is principally elicited by condensed tannins in diversified chemical structures. The influence of DP size of condensed tannins on astringency perception remains unclear for decades. In the present study, the astringency intensity of purified and identified grape oligomeric tannins (DP ranged from 1 to 5) was firstly explored. A novel non-solid phase strategy was used to rapidly exclude the galloylated PAs from the non-galloylated PAs and fractionate the latter according to their DP size. Then, a series of PAs with individual DP size and galloylation were purified. Furthermore, purified compounds were identified by both normal phase HPLC-FLD and reverse phase UHPLC-ESI-Q-TOF. Finally, the contribution of the astringency perception of the individual purified tannins was examined with a salivary protein binding ability test. The results were observed by HPLC-FLD and quantified by changes in PA concentration remaining in the filtrate. In summary, a new approach without a solid stationary phase was developed to isolate PAs according to their DP size. And a positive relationship between the DP of PAs and salivary protein affinity was revealed.

International audience; The study describes bioactive compounds as inhibitors of acetylcholinesterase (AChE), from the stem bark extract of Montrouziera cauliflora, selected among 19 dichloromethane extracts from Clusiaceae species. Our work focused on the development of an original normal phase HPLC microfractionation strategy to rapidly assess highly active zones from this crude active non-polar plant extract. Two different microfraction collection methods were evaluated for the assessment of the AChE inhibition. Two guttiferones and a tocotrienol were directly isolated among five compounds identified off-line by NMR after upscaling the fractionation and their AChE inhibition was evaluated. The strengths and weaknesses of the two microfractionation collection methods for HPLC-AChE activity-based profiling are discussed.

A Plackett-Burman design was used for screening 12 variables that could affect the mass spectrometry signals of phosphatidylcholines (PtdCho) and proposing optimal fragmentation conditions to study the fragmentation mechanisms of PtdCho standards. Under optimal conditions, three well-established methods for extracting phospholipids from biological samples, specifically liquid-liquid extraction (LLE), normal phase liquid chromatography (NPLC) and high performance thin layer chromatography (HPTLC), were compared in terms of the number of regiospecifically characterized PtdCho by means of liquid chromatography three-stage mass spectrometry (LCMS 3 ). The same number of PtdCho species (35) were characterized by LCMS3 in the LLE and NPLC fractions, whereas only 15 in the HPTLC fraction.

While studying superfluid 3He of 2.4 MPa in 97.5 %-porosity aerogel with NMR/MRI techniques, we find that the TC is reduced when more than adequate amount of 4He, which covers the surface of silica strands, is introduced. For a sample, whose TC is reduced to as low as 0.9 mK, we find that the spin diffusion coefficient in the normal phase is increased by a factor of 1.56 both in high temperature region, where 3He-3He scattering dominates, and in low temperature region, where 3He-aerogel scattering dominates. This enhancement is attributed to a modification of Landau parameter \(F_{0}^{a}\) from −0.757 to −0.62, which is a change towards less ferromagnetic direction. The modification of microscopic quantity could be explained if small amount of 4He has homogeneously mixed into liquid 3He in the aerogel.

An international collaborative study was conducted on an HPLC method with fluorescent detection (FLD) for the determination of flavanols and procyanidins in materials containing chocolate and cocoa. The sum of the oligomeric fractions with degree of polymerization 1–10 was the determined content value. Sample materials included dark and milk chocolates, cocoa powder, cocoa liquors, and cocoa extracts. The content ranged from approximately 2 to 500 mg/g (defatted basis). Thirteen laboratories representing commercial, industrial, and academic institutions in six countries participated in the study. Fourteen samples were sent as blind duplicates to the collaborators. Results from 12 laboratories yielded repeatability relative standard deviation (RSDr) values that were below 10% for all materials analyzed, ranging from 4.17 to 9.61%. The reproducibility relative standard deviation (RSDR) values ranged from 5.03 to 12.9% for samples containing 8.07 to 484.7 mg/g. In one sample containing a low content of flavanols and procyanidins (approximately 2 mg/g), the RSDR was 17.68%. Based on these results, the method is recommended for Official First Action for the determination of flavanols and procyanidins in chocolate, cocoa liquors, powder(s), and cocoa extracts.

A high-performance counter-current chromatography (HPCCC) method was applied for the first time for the preparative separation and purification of three rare compounds which occur as minor constituents in the fruits of Peucedanum alsaticum L.: 5-substituted coumarin notoptol and two dihydropyranochromones: divaricatol and ledebouriellol. A scale-up process from analytical to preparative in a very short time was developed. In order to purify a range of rare and minor compounds with different polarity two separate experiments were performed, one in reverse phase, the other in normal phase, using the same crude extract. A two-phase solvent system composed of n-hexane/ethyl acetate/methanol/water (1:1:1:1) was developed. The components purified and collected were analyzed by high-performance liquid chromatography. The method yielded 0.7 mg of notoptol, 1.46 mg of ledebouriellol at purity of 99.5%, and 10 mg of mixtures of divaricatol, alsaticol and alsaticocoumarin, where divaricatol present 22% by peak area. These amounts were obtained from 1 g of the crude extract in a single run. This is the first time when minor notoptol, ledebouriellol, and divaricatol were isolated in a single run using HPCCC method and first time when these were identified in plant from Peucedanum genus.

Simultaneous quantification of Lamivudine and Zidovudine in tablets by HPTLC method was developed and validated. The chromatograms were developed using a mobile phase of toluene:ethyl acetate:methanol (4:4:2, v/v/v) on pre-coated plate of silica gel GF aluminum TLC plate and quantified by densitometric absorbance mode at 276 nm. The Rf values were 0.41±0.03 and 0.60±0.04 for Lamivudine and Zidovudine, respectively. The linearity of the method was found to be within the concentration range of 50â250 ng/spot for Lamivudine and for Zidovudine, it was 100â500 ng/spot. The lower limits of detection and quantification were 2.23 ng/spot and 7.90 ng/spot for Lamivudine and 2.90 ng/spot and 8.85 ng/spot for Zidovudine. The method was also validated for precision, specificity and recovery. This developed method was used to analyze fixed-dose tablets (Duovir, Cipla Ltd) samples of Lamivudine and Zidovudine. Keywords: Normal-phase HPTLC, Lamivudine, Zidovudine, Methanol

The rapidly developing interest in nanofluidics, which is used to examine liquids on an order that ranges from an attoliter to a femtoliter, correlates with the recent interest in decreased sample amounts, such as in the field of single-cell analysis. For general nanofluidic analysis, the fact that a pressure-driven flow does not limit the choice of solvents (aqueous or organic) is an important aspect. In this paper, an automated injection system using a pressure-driven flow for several hundred nanometer-sized channels (extended nanochannels) is described. By automatically, and independently, switching four pressure lines using solenoid valves controlled by a sequencer with a time resolution of 10 ms, 550 aL sample band in minimum was reproducibly injected under normal phase conditions. The reproducibility of the band injection was improved by one order when compared with the previous injection method, which enables determination of time zero for injection. These facts are essential for the further band analysis in nanochannels, where diffusion is dominant. This injection system using pressure-driven flow can be used with any kind of solvent, which should make it a significant tool for nanofluidic applications, such as immunoassay, DNA analysis, and chromatography.

This paper considers the following collective significance of the shared, clinical characteristics of the major mental disorders (MMDs), their co-morbidities, overlaps and pharmacological responses with the following conclusions: 1) These disorders have a common, initial, neurodevelopmental origin. 2) They can occur probabilistically on susceptible individuals, on account of pre-existing, extreme, temperamental variances-signifying underlying structural variance. 3) Each of these syndromes can be considered the expression of disturbances in the overall, common, operating mode of brain function which normally ensures the synchrony, coordination, elegance and subtlety in the expression of all the brain’s higher faculties. 4) Lastly, this function is a complex, emergent phenomenon based on the individual’s temperamental/structural underlying makeup, switching intermittently from a normal phase to a pathologically, ordered one-the latter phase expressing itself with symptoms made up of expressing either/or, antithetical substitutes for each of the MMDs-similar to the fluctuations found in patient’s with Parkinson’s disease.

Fish oil is considered a healthy food due to the presence of large amounts of polyunsaturated fatty acids (PUFAs), especially in the form of n-3 fatty acids 5,8,11,14,17-eicosapentaenoic acid (20:5n-3; EPA) and 4,7,10,13,16,19-docosahexaenoic acid (22:6n-3; DHA). However, fish oil is known to contain many other PUFAs, some of which are uncommon and whose bioactivity is scarcely investigated. In this study, we isolated the rare PUFA 6,9,12,15-hexadecatetraenoic fatty acid (16:4n-1) which bears a double bond on the terminal carbon from fish oil in form of its methyl ester. We used high-speed counter-current chromatography (HSCCC) for the fractionation of 500 mg-portions of fatty acid methyl esters prepared from a fish oil capsule and investigated the fractions by GC/MS. Twenty-eight 13-mL fractions were collected and fatty acid methyl esters were detected in fractions 11–23. The elution was carried out in normal phase mode, providing the long-chained saturated and monoenoic fatty acids first. More than 100 fatty acids ranging from 10:0 to 26:0 could be identified in the HSCCC fractions, and most of them were polyunsaturated. The reproducibility of the HSCCC method was shown by repeated injection of the fish oil and the fractions containing 6,9,12,15-hexadecatetraenoic fatty acid (16:4n-1). The late eluting 16:4n-1 methyl ester was isolated in pure form and its structure was verified.

Earlier, a set of pharmaceuticals with different chemical structures has been used to evaluate the enantioselectivity of four recently commercialized polysaccharide-based chiral stationary phases, Lux ® Cellulose-1/Sepapak ® 1, Lux ® Cellulose-2/Sepapak ® 2, Lux ® Amylose-2/Sepapak ® 3 and Lux Cellulose-4/Sepapak ® 4 and of three Daicel columns, Chiralpak ® AD-H, Chiralcel ® OD-H and Chiralcel ® OJ-H, using the screening conditions of an existing generic separation strategy in normal-phase liquid chromatography (NPLC). In this study, the applicability of the optimization steps of the existing separation strategy was examined using 44 drugs (70 optimization cases) representing the three possible resolution situations that occur after screening. Optimizations are demonstrated by modifying parameters such as polar modifier percentages, temperatures, flow rates and additives concentration. Changing the percentage of polar modifier was found to have the largest influence on the resolution. The resolution, peak shape and the analysis time were nicely improved for 49/70 cases (70%) after the application of the original optimization steps. The introduction of some modifications to the original optimization increased this number from 49 to 62 cases, i.e. from 70% to 88.6%. Finally, an updated generic separation strategy in NPLC was proposed.

Four recently commercialized polysaccharide-based chiral stationary phases, Sepapak(®) 1, Sepapak(®) 2, Sepapak(®) 3, and Sepapak(®) 4, now called Lux(®) Cellulose-1, Lux(®) Cellulose-2, Lux(®) Amylose-2 and Lux(®) Cellulose-4, respectively, were examined for their enantioselectivity on a set of 61 racemic compounds by applying the screening conditions of a previously developed chiral screening strategy in normal phase liquid chromatography (NPLC) [N. Matthijs et al., J. Chromatogr. A 1041 (2004) 119-133]. The enantioselectivity on these phases was compared to that on the initial set of polysaccharide-based phases, Chiralpak(®) AD-H, Chiralcel(®) OD-H, and Chiralcel(®) OJ-H, used in the earlier defined strategy. The results showed that 53 compounds out of 61 (86.9%) were resolved on the initial set of chiral stationary phases (CSPs) using two mobile phases per compound, either heptane-ethanol-diethylamine (DEA) or heptane-isopropanol-DEA for testing basic compounds and heptane-ethanol-trifluoroacetic acid (TFA) or heptane-isopropanol-TFA for acidic, bifunctional and neutral compounds. The recently commercialized set of columns gave 54 separations in total (88.5%). Our results indicated that ethanol (EtOH) as polar modifier provides a higher success rate and better resolutions than isopropanol (IPA) on both sets of stationary phases. However, the usefulness of the mobile phase with IPA as polar modifier cannot be neglected for complementarity reasons. It was found that the screening is improved by the introduction of the recently commercialized polysaccharides based CSPs since they provided enantioseparation for compounds that were not resolved by the traditional CSPs. The combination between the initial and the recently commercialized CSPs showed enantioresolution for 55 compounds out of 61 (90%), among which 47 were baseline resolved.

There is considerable current interest in coenzyme Q10 (CoQ10) from a medical perspective. CoQ10 has been shown to alleviate the side effects of statin drugs, for instance, and so there is a push to find naturally high producers of the compound. Sporidiobolus johnsonii (S. johnsonii) has been reported to produce CoQ10 in studies that used only standards on thin-layer chromatography (TLC) and also suggested the production of coenzyme Q9 (CoQ9). This work set out to verify CoQ9/CoQ10 production in S. johnsonii and quantify as appropriate. We show that S. johnsonii produces CoQ10 but found no evidence for CoQ9 biosynthesis. The specific production of CoQ10 was noted at 10 mg/g dry cell weight (DCW) in media supplemented with 4-hydroxybenzoic acid (HBA). This makes S. johnsonii a naturally high CoQ10 producer. New methods for extraction and purification of CoQ10 are also discussed, and identification of a closely eluting side product under normal phase isolation is reported.

The free energy of adsorption (S°), and the surface area of adsorption (AS) on silica and alumina surfaces of 17 carboxamide fungicides was determined by thin-layer chromatography (TLC) using silica and alumina stationary phases. The relationships between the measured physicochemical parameters of analytes and the relationships between these parameters and 29 computed physicochemical characteristics were calculated by linear regression analysis and the Fisher's test. It was found that the adsorption characteristics of stationary phases are significantly different while the similar parameters of carboxamide derivatives showed marked similarities. It was further established that in the majority of cases the computed and measured physicochemical parameters are not correlated. This finding indicates that the free energy of adsorption and the surface area of adsorption can be used as new independent variables in both Quantitative Structure Activity Relationship (QSAR) and Quantitative Structure Retention Relat...

This paper presents the development and validation of an improved method for the simultaneous analysis of lamivudine (LVD), stavudine (STV) and nevirapine (NVP) using high-performance thin-layer chromatography (HPTLC) with densitometric detection. Separation was performed on silica gel 60F(254) plates. The mobile phase is comprised of ethylacetate, methanol, toluene and concentrated ammonia (38.7:19.4:38.7:3.2, v:v:v:v). Detection wavelength was 254 nm. The R(f) values were 0.24±0.03, 0.38±0.04 and 0.69±0.04 (n=8) for LVD, STV and NVP, respectively. An F-test indicated that calibration graphs were adequately linear at the evaluated concentration ranges. The pooled %RSD for repeatability of the percentage amount recovered for LVD, STV and NVP were found to be 0.62, 0.54, and 0.79, and the pooled %RSD for time-different intermediate precision were 1.66, 1.27 and 1.21. The percentage recoveries for the trueness were 99.2%±1.5 for LVD, 98.6%±1.5 for STV and 99.3%±1.7 for NVP (n=3). Most factors evaluated in the robustness test were found to have an insignificant effect on the selected responses at 95% confidence level. This method was successfully used to analyze fixed-dose tablets samples of LVD, STV and NVP.

Honey is a rich conventional natural resource of sweetness and energy for human beings. A protocol for the determination of two important monosaccharide sugars (fructose and glucose) in honey was established in the current study by using normal phase partition liquid chromatography and 1–5% combined working standard of glucose, fructose and sucrose.

Aim: The study aims to develop a simple, rapid and economical normal phase thin layer chromatography (TLC) method for identification and quantification of 5,7-dichloroquinolin-8-ol and 5-chloroquinolin-8-ol, two active ingredients of halquinol, an antimicrobial agent. Materials and Methods: The analysis was performed on silica gel 60 TLC plates pre-washed with disodium ethylenedinitrilotetraacetic acid disodium salt (Na 2 EDTA) solution with methanol-ethyl acetate-iso-propyl alcohol-ammonia solution [8:20:1:0.6 (v/v)] as the mobile phase. Detection and quantification was performed densitometrically at 247 nm. Results: Responses of both 5,7-dichloroquinolin-8-ol and 5-chloroquinolin-8-ol were linear functions of concentration in the range of 300-800 ng. The intraday precision and intermediate precision of the method for 5,7-dichloroquinolin-8-ol and 5-chloroquinolin-8-ol was determined and it was found to be precise. Conclusion: The TLC method developed for simultaneous quantitative determination of 5,7-dichloroquinolin-8-ol and 5-chloroquinolin-8-ol was found to be simple and economical. Therefore, it can be used in routine quality control analysis of halquinol in bulk drug powder and halquinol bolus.

Due to unavailability of a vaccine and a specific cure to dengue, the focus nowadays is to develop an effective vector control method against the female Aedes aegypti mosquito. This study aims to determine the larvicidal fractions from Piper nigrum ethanolic extracts (PnPcmE) and to elucidate the identity of the bioactive compounds that comprise these larvicidal fractions. Larvicidal assay was performed by subjecting 3rd to 4th A. aegypti instar larvae to PnPcmE of P. nigrum. The PnPcmE exhibited potential larvicidal activity having an LC50 of 7.1246 ± 0.1304 ppm (mean ± Std error). Normal phase vacuum liquid chromatography of the PnPcmE was employed which resulted in five fractions, two of which showed larvicidal activity. The most active of the PnPcmE fractions is PnPcmE-1A, with an LC50 and LC90 of 1.7101 ± 0.0491 ppm and 3.7078 ppm, respectively. Subsequent purification of PnPcmE-1A allowed the identification of the larvicidal compound as oleic acid.

E-mail: yhkim@kbsi.re.krReceived August 7, 2013, Accepted August 28, 2013Key Words : High mannose oligosaccharides, Amide-80, 2-AB, LC-MALDIThe addition of carbohydrates to proteins is one of theimportant post-translational modifications of proteins. Glyco-proteins in many biological processes play a key role inimmune defense, cell growth and cell–cell adhesion.

In this study, a comprehensive 2-D chromatography was constructed, consisting of normal phase LC (NPLC) with a CN column as the first dimension, and supercritical fluid chromatography (SFC), with a Merck Chromolith Flash C(18) column as the second dimension, which were connected by a 10-port, dual-position valve controlled automatically by a self-designed software. Such platform was applied into the analysis of the fruiting bodies of Ganoderma lucidum, a traditional Chinese medicine, and within 2 h analysis, the obtained peak capacity of the 2-D-NPLC-SFC system was about 350, obviously higher than that of each dimension. These results demonstrate that 2-D-NPLC-SFC is not only of good orthogonality, but also of high throughput for the analysis of complex samples.

We compute the momentum distribution of a homogeneous Fermi gas at unitarity in the normal phase within the framework of the non-self-consistent T-matrix approximation with particle-hole fluctuation. From the large-momentum behavior of momentum distribution, we obtain the contact for the unitary Fermi gas. We also compare our results with experimental data and other theoretical predictions.

Ginsenoside-Ro which belongs to the oleanane-type saponins has anti-inflammatory, anti-platelet, anticomplementary and immunomodulatory activities. The present paper described the preparation of ginsenoside-Ro from panax ginseng with high recovery and efficiency by combination of normal-phase medium-pressure liquid chromatography (NP-MPLC) and high-performance counter-current chromatography (HPCCC). The crude sample was preliminarily chromatographed by NP-MPLC to enrich ginsenoside-Ro to the purity of 70.2% with 95.0% recovery. Then, the enriched sample was further purified by HPCCC with a solvent system composed of ethyl acetate–isopropanol–0.1% formic acid (3:1:5, v/v), where 61 mg ginsenoside-Ro was obtained from 100 mg enriched sample with 96.0% purity and 83.4% recovery. The overall recovery of ginsenoside-Ro was 79.2%, whose structure was identified by liquid chromatography–electrospray ionization mass spectrometry (LC–ESI-MS) finally.

Two types of chiral stationary phases for HPLC based on pi-acidic or pi-basic perphenylcarbamoylated beta-CDs were synthesized. The relative structural features of the two effective chiral selectors are discussed and compared in both normal-phase and RP modes. In addition, the nature and concentration of alcoholic modifiers were varied for optimal separation in normal phase and the structural variation of the analytes was also examined. The results showed that hydrogen bonding, steric effect and pi-acidic-pi-basic interaction contributed greatly to enantioseparation. Upon comparison, some of the differences in the separation behavior of the two types of chiral stationary phases might be due to the pi-acidic or pi-basic phenylcarbamate groups.

Comprehensive two-dimensional HPLC (2DLC) has been used very successfully in proteomics applications for over a decade. Increasingly we are seeing online, comprehensive 2DLC used for non-proteomic applications. This article gives an overview of the state of the art of this technique, with emphasis on current trends in theory and practice that are exciting and hold the most promise for advancing the performance of 2DLC. Specifically, the recently commercialized small, superficially porous packing materials are very well suited to use in the second dimension of online 2DLC where analysis speed is critical and largely dictates the performance of the 2DLC system. Further, the recent development of optimization schemes and associated software that support the use of different second-dimension elution modes in a single 2DLC analysis will improve the flexibility and effectiveness of 2DLC separations. Excluding separations of peptides, proteins, and polymers, 2DLC systems utilizing reversed-phase separation in one dimension, and either normal phase or reversed-phase in the other dimension continue to be the most popular. Although these systems have been applied mostly to complex biological materials, we are beginning to see applications in the analysis of pharmaceutical materials for ingredient purity and degradation profiling. The general lack of robust, easy-to-use commercially available software is arguably the greatest impediment to wider application of 2DLC methods. This situation is improving slowly, however, and at least two commercially available software packages have been described in the peer-reviewed literature. This is an exciting time in the development of online 2DLC.

A simple, precise, and accurate method is developed and validated for the analysis of pseudophedrine hydrochloride, dextromethorphan hydrobromide, chlorpheniramine maleate, and paracetamol in tablet formulations. The method has shown adequate separation of the four ingredients from each other. Separation was achieved on a silica column (5 μm, 125 × 4.6 mm inner diameter) using a mobile phase consisting of methanol/ammonium dihydrogen phosphate buffer (90:10, v/v) at a flow rate of 1.0 ml/min and UV detection at 220 nm. This new method is validated in accordance with USP requirements for new methods for assay determination, which include accuracy, precision, selectivity, linearity and range, robustness and ruggedness. The current method demonstrates good linearity over the range of 0.15-0.45 mg/ml of pseudophedrine hydrochloride with r (2) of 0.996, and in the range of 0.075-0.225 mg/ml of dextromethorphan hydrobromide with r (2) of 0.992, and in the range of 0.01-0.03 mg/ml of chlorpheniramine maleate with r (2) of 0.994, and in the range of 0.25-0.75 mg/ml of paracetamol with r (2) of 0.991. The average recovery of the method is 99.7%, 98.6%, 98.1%, and 99.2% for pseudophedrine hydrochloride, dextromethorphan hydrobromide, chlorpheniramine maleate, and paracetamol, respectively. The degree of reproducibility of the results obtained as a result of small deliberate variations in the method parameters and by changing analytical operator has proven that the method is robust and rugged.

The stratum corneum owns a barrier function, which can be altered by a modification of its lipid composition. In this work, a new simple method was developed in normal phase liquid chromatography to separate the three major lipid classes of the stratum Corneum, fatty acids, ceramides, and cholesterol. A quantitative investigation was carried out, comparing an internal normalisation and an external standardisation with two universal detectors: an evaporating light scattering detector and a charged aerosol detector, the Corona. The study points out the fact that the external standardisation is suitable for a quantitative study of the different lipid classes, using a representative standard for each class. Moreover, the use of the Corona is more adapted for further investigation, due to a better repeatability, accuracy, and precision. A test made on a lipid extract from the forearm of volunteers shows that the present method is appropriate for biological extract analysis.

The liquid chromatographic retention in normal phase mode was quantitatively analyzed in silico using chromatographic retention of sleeping medicines measured in acidic, basic, and neutral organic solvent mixtures. Hydrogen bonding is the major contribution in the retention that was supported by a high correlation coefficient between log k and hydrogen bonding energy values calculated using a molecular mechanics program.

(1 R,2 R)-(+)-1,2-Diphenylethylenediamine was copolymerized with terephthaloyl chloride and toluene 2,4-diisocyanate at different fed ratios to give two polymeric chiral selectors. The selectors were immobilized onto 3-aminopropyl silica gel to afford corresponding chiral stationary phases. The enantioseparation evaluation reveals the shorter-chain polymeric selector possesses better enantioseparation ability. In normal phase mode, tert-butanol is advantageous for enantioseparation when it is used as one of the mobile phase compositions. The influence of other aspects including selector structure, sample loading and temperature on the enantioseparation ability of these chiral stationary phases was also studied.

Tuberculosis has been a scourge of humans over many millennia, but questions remain regarding its evolution and epidemiology. Fossil biomarkers, such as DNA and long-chain mycolic acids, can be detected in ancient skeletal and other materials. The phthiocerol dimycocerosate waxes are also robust biomarkers for tuberculosis and sensitive methods are available for the detection of their mycocerosic acid components. The presence of mycocerosic acids was investigated in 49 individuals from the 1837-1936 Coimbra Identified Skeletal Collection (Portugal), half with documentary data indicating tuberculosis as a cause of death. Samples were hydrolysed, acidic components converted to pentafluorobenzyl esters, the non-hydroxylated long-chain esters isolated, and this fraction separated into multimethyl-branched and other esters by normal phase high performance liquid chromatography. Negative ion chemical ionisation gas chromatography mass spectrometry was used to detect diagnostic C29, C30 and C32 mycocerosic acids. Mycocerosic acids were detected in archaeological material for the first time, illustrating that they are valuable biomarkers for the diagnosis of ancient tuberculosis. A 72% correlation with the Coimbra burial record supported TB as the major cause of death. In addition, 30% of the skeletons, positive for mycocerosates, showed the presence of related long-chain mycolipenic acids.