This blog has been set up for editors, reviewers, authors and readers of Elsevier's Analytical Chemistry Journals - all of which can be seen below. It will be updated from Monday to Friday with general news and announcements concerning the titles listed on this page. It should be noted that the views or claims made in the news items and feeds are not necessarily those of the Publisher.
World Congress on Biosensors 2014
Biosensors 2014
Tuesday 18 December 2012
Just Published: Journal of Pharmaceutical and Biomedical Analysis
A new issue of this journal has just
been published. To see abstracts of the papers it contains (with links through
to the full papers) click here:
5 March 2013 Publication year:
2013 Source:Journal of Pharmaceutical and Biomedical Analysis, Volume
75
In this study, an efficient strategy based on bioassay-guided
fractionation, high-performance liquid chromatography/electrospray ionization
quadrupole time-of-flight mass spectrometry (HPLC-ESI-Q/TOF-MS) and high-speed
counter-current chromatography (HSCCC) was established to screen and purify
bioactive compounds from Chinese herbal medicines (CHMs). This screening system
was efficient and successfully applied to reveal anti-prostate cancer candidates
from Puerariae thomsonii Flos. As a result, an active fraction with strong in
vitro anti-prostate cancer activity was obtained, and the main compounds in the
fraction were purified by HSCCC, giving 82mg of tectoridin, 36mg of
tectorigenin-7-O-[β-d-xylopyranosyl-(1→6)-β-d-glucopyranoside and 64mg of
tectorigenin. Among them, tectorigenin, possessing the highest anti-prostate
cancer activity with IC50 value of 0.08μM, has priority to be lead compound. The
results of this work demonstrated that the developed method was efficient and
could be employed for the rapid screening, identification and purification of
active components from CHMs.
Graphical abstract
Highlights
► An efficient strategy
based on bioassay-guided fractionation, HPLC-ESI-Q/TOF-MS and HSCCC was
established to screen and purify bioactive compounds from CHMs. ► The screening
system succeeded in discovering anti-prostate cancer candidates from Puerariae
thomsonii Flos. ► Tectoridin,
tectorigenin-7-O-[β-d-xylopyranosyl-(1→6)-β-d-glucopyranoside and tectorigenin
were prepared from Puerariae thomsonii Flos by HSCCC for the first time. ►
Tectorigenin possessed potent inhibition effect on growth of RM-1 prostate
cancer cells with IC50 value of 0.08μM.
5 March 2013 Publication year:
2013 Source:Journal of Pharmaceutical and Biomedical Analysis, Volume
75
Dimethyl sulfate (DMS) is frequently used in pharmaceutical
manufacturing processes as an alkylating agent. Trace levels of DMS in drug
substances should be carefully monitored since the compound can become an
impurity which is genotoxic in nature. Derivatization of DMS with dibenzazepine
leads to formation of the N-methyl derivative, which can be retained on a
reversed phase column and subsequently separated from other potential
impurities. Such derivatization occurs relatively slowly. However, it can be
substantially speed up if ionic liquids are used as reaction media. In this
paper we report the use of 1-butyl-1-methylpyrrolidinium
bis(trifluoromethylsulfonyl)imide (IL1) and 1-butyl-4-methylpyridinium
tetrafluoroborate (IL2) as reaction media for the derivatization of DMS with
dibenzazepine. It was determined that the stoichiometry between the substrate
and DMS may be 1:1 or 2:1, in relation with the nature of the reaction media. An
(+)ESI-MS/MS approach was used for quantitation of the derivatized product.
Alternatively, DMS derivatization may be carried out with pyridine in
acetonitrile (ACN). The N-methylpyridinium derivative was separated by
hydrophilic interaction liquid chromatography (HILIC) and detected through
(+)ESI-MS (in the SIM mode). In both cases, a limit of quantitation (LOQ) of
0.05μg/ml DMS was achievable, with a linearity range up to 10μg/ml. Both
analytical alternatives were applied to assay DMS in 4-(2-methoxyethyl)phenol,
which is used as a starting material in the synthesis of metoprolol.
Graphical abstract
Highlights
► LC/MS–MS analysis at
sub-ppm level of dimethyl sulfate in starting materials for APIs is proposed. ►
Derivatization of DMS with dibenzazepine or pyridine was achieved. ►
Derivatization kinetics was studied in acetonitrile and ionic liquids
(pseudo-first-order). ► Derivatization with dibenzazepine in ionic liquids is
much faster than in acetonitrile. ► RPLC (for N-methyl-dibenzazepine) and HILIC
(for N-methyl-pyridine) separation modes were used.
5 March 2013 Publication year:
2013 Source:Journal of Pharmaceutical and Biomedical Analysis, Volume
75
This paper presents the development of a new method for the simple and
reliable quantification of the free drug amount in liposomal preparations of
prednisolone phosphate (PP). In this method the free drug is distinguished from
the encapsulated drug by means of hydrolysis of the free PP into prednisolone
(P) by alkaline phosphatase (AP). During method development reaction progress
curves were recorded to determine the required AP concentration and the
corresponding incubation time to achieve hydrolysis of all free PP. Reaction
progress curves also showed that small changes in the amount of weighted AP and
the incubation periods used do not cause a change in outcome. Further, several
organic solvents were tested as precipitation solvent and the use of
tetrahydrofuran (THF) yielded clean chromatograms, rapid AP deactivation and
complete liposome rupture avoiding under- and overestimations of the
encapsulated and free drug concentrations. Method accuracy was evaluated during
a cross-validation involving dialysis. Intra- and interday precision were
evaluated by determining the standard deviation (SD) and relative standard
deviation (RSD) after applying the new method on one day (n =4) and on different
days (n =3). The accuracy of the developed method is comparable to the accuracy
determined by dialysis, while clearly the method using AP is more precise. In
conclusion, comprehensive method development yielded an accurate and precise
method, which can replace traditional methods like dialysis and solid phase
extraction (SPE). With little effort the method can be upgraded and become part
of the liposome certification prior to human use. The overall principle behind
the method offers possibilities for many drug carrier systems.
Highlights
► A method for the quantification of the free drug
amount in liposomal preparations of prednisolone phosphate was developed. ► The
free drug is distinguished from the encapsulated drug by means of enzymatic
hydrolysis. ► In this way difficulties accompanying traditional separation
techniques were circumvented. ► Thismethod is reliable, accessible,
inexpensive,fast and suitable for small sample volumes and a large number of
samples. ► The principle behind this method offers also possibilities for the
free drug determination of many drug carrier systems.
5 March 2013 Publication year:
2013 Source:Journal of Pharmaceutical and Biomedical Analysis, Volume
75
Nine polysaccharide-based chiral stationary phases (CSPs) were used to
define a separation strategy that combines normal-phase (NP), reversed-phase
(RP) and polar organic solvent chromatography (POSC) modes. After limiting
ourselves to two CSPs per mode, in total, five CSPs, Chiralpak AD (NP),
Chiralcel OD (RP and POSC), Lux Cellulose-1 (NP), Lux Cellulose-2 (POSC) and Lux
Cellulose-3 (RP), showed the broadest enantioselectivity and most
complementarity. Six sequences of the three modes were considered to decide
which sequence is the most successful for screening a set of 56 pharmaceutical
compounds. Starting the strategy with the NP mode, followed by RP and finally
POSC was found preferable from both the number of cumulative separations and of
baseline separations. Two approaches were considered for strategy fine tuning
using an additional set of eight racemic mixtures. In both approaches, seven of
the eight compounds were baseline resolved, on one of the examined columns at
either screening or optimization conditions of a mode. One approach was finally
preferred because of its lower workload.
Highlights
► 56 compounds and nine CSPs were used to update
strategies in three common HPLC modes. ► An HPLC chiral method development
strategy that combines NPLC, RPLC and POSC modes was defined. ► Success rate:
all compounds were separated with the updated strategy in less experiments. ►
The updated strategy was fine tuned.
5 March 2013 Publication year:
2013 Source:Journal of Pharmaceutical and Biomedical Analysis, Volume
75
A microflow chemiluminescence (CL) sensor for determination of dibutyl
phthalate (DBP) based on magnetic molecularly imprinted polymer (MMIP) as
recognition element was fabricated. Briefly, a hydrophilic molecularly imprinted
polymer layer was produced at the surface of Fe3O4@SiO2 magnetic nanoparticles
(MNPs) via combination of molecular imprinting and reversible stimuli responsive
hydrogel. In this protocol, the initial step involved co-precipitation of
Fe2+ and Fe3+ in an ammonia solution. Silica was then
coated on the Fe3O4 nanoparticles using a sol–gel method to obtain silica shell
magnetic nanoparticles. The MMIP was synthesized using methacrylic acid (MAA) as
functional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linker
and 2, 2-azobisisobutyronitrile (AIBN) as initiator in chloroform. Then the
synthesized MMIP and magnetic non-molecular imprinted polymers (MNIP) were
employed as recognition by packing into lab-made straight shape tubes, connected
in CL analyzer for establishing the novel sensor with a single channel syringe
pump. And a mixer for hydrolyzing of DBP was followed. Based on this experiment
principle, DBP was determined indirectly. And the MMIP showed satisfactory
recognition capacity to DBP, resulting to the wide linear range of
3.84×10−8 to 2.08×10−5 M and the low detection limit of
2.09×10−9 M (3σ) for DBP. The relative standard deviation (RSD) for
DBP (3.20×10−6 M) was 1.40% (n =11). Besides improving sensitivity
and selectivity, the sensor was reusable. The proposed DBP–MMIP–CL sensor has
been successfully applied to determine DBP in drink samples.
Graphical abstract
Highlights
► Fe3O4@SiO2 was used as
support for easier to control. ► Microscale Syringe Pump was used for saving
reagent. ► A mixer for hydrolyzing was used for
chemiluminescence.
5 March 2013 Publication year:
2013 Source:Journal of Pharmaceutical and Biomedical Analysis, Volume
75
In this work, a dispersive liquid–liquid microextraction (DLLME)
procedure combined with ultra-high performance liquid chromatography with
diode-array detection was developed to determine 25 antibiotics in mineral and
run-off waters. Optimum DLLME conditions (5mL of water at pH=7.6, 20% (w/v)
NaCl, 685μL of CHCl3 as extractant solvent, and 1250μL of ACN as disperser
solvent) allowed the repeatable, accurate and selective determination of 11
sulfonamides (sulfanilamide, sulfacetamide, sulfadiazine, sulfathiazole,
sulfadimidin, sulfamethoxypyridazine, sulfadoxine, sulfamethoxazole,
sulfisoxazole, sulfadimethoxine and sulfaquinoxaline) and 14 quinolones
(pipemidic acid, marbofloxacin, fleroxacin, levofloxacin, pefloxacin,
ciprofloxacin, lomefloxacin, danofloxacin, enrofloxacin, sarafloxacin,
difloxacin, moxifloxacin, oxolinic acid and flumequine). The method was
validated by means of the obtention of calibration curves of the whole method as
well as a recovery study at two levels of concentration. The LODs of the method
were in the range 0.35–10.5μg/L with recoveries between 78% and 117%.
Graphical abstract
Highlights
► A DLLME–UHPLC-DAD
method was developed to determine antibiotics in water. ► A total of 25
compounds (11 sulfonamides and 14 quinolones) was analyzed. ► Relative
recoveries values of the method were between 74% and 117%. ► The procedure is
simple, fast and reliable to determine the selected antibiotics.
5 March 2013 Publication year:
2013 Source:Journal of Pharmaceutical and Biomedical Analysis, Volume
75
Oral squamous cell carcinoma (OSCC) is an aggressive cancer and its
occurrence is closely related to betel nut chewing in Taiwan. However, there are
few prognostic and diagnostic biomarkers for this disease especially for its
association with betel nut chewing. Recent progresses in quantitative proteomics
have offered opportunities to discover plasma proteins as biomarkers for
tracking the progression and for understanding the molecular mechanisms of OSCC.
In present study, plasma samples from OSCC patients with at least 5-year history
of betel nut chewing and healthy donors were analyzed by fluorescence
2D-DIGE-based proteomic analysis. Totally, 38 proteins have been firmly
identified representing 13 unique gene products. These proteins mainly function
in inflammatory responses (such as fibrinogen gamma chain) and transport
(Apolipoprotein A–I). Additionally, the current quantitative proteomic approach
has identified numerous OSCC biomarkers including fibrinogen (alpha/beta/gamma)
chain, haptoglobin, leucine-rich alpha-2-glycoprotein and ribosomal protein S6
kinase alpha-3 (RSK2) which have not been reported and may be associated with
the progression and development of the disease. In summary, this study reports a
comprehensive patient-based proteomic approach for the identification of
potential plasma biomarkers in OSCC. The potential of utilizing these markers
for screening and treating OSCC warrants further investigations.
Graphical abstract
Highlights
► Oral squamous cell
carcinoma (OSCC) is an aggressive cancer closely related to betel nut chewing. ►
Quantitative proteomics have offered opportunities to discover plasma OSCC
protein biomarkers. ► This study identified numerous unreported OSCC markers
such as RSK2. ► The utilization of these markers for screening and treating OSCC
warrants further investigations.
5 March 2013 Publication year:
2013 Source:Journal of Pharmaceutical and Biomedical Analysis, Volume
75
Psoralea corylifolia L. (Fabaceae) is a traditional Chinese medicine
with many beneficial effects in medical therapies. Bakuchiol was the main active
ingredient of Psoralea corylifolia L. In this study, a novel method of
pre-column derivatization with dansyl chloride followed by analysis of ultra
high-performance liquid chromatographic–tandem mass spectrometry (UHPLC–MS/MS)
was established and validated for quantification of bakuchiol in rat plasma. The
linearity of this approach was confirmed to be within the concentration range of
0.5–1000ng/mL and the lower limit of quantification was at 0.5ng/mL. The total
analysis time was 1.5min for each pretreated sample. Also, the precision,
accuracy, stability, recovery and matrix effect of this method were proved to
meet the requirements for bioanalysis. The intravenous and oral pharmacokinetic
profiles of bakuchiol were obtained by utilizing this approach. The oral
bioavailability of bakuchiol in rats (3.2%) was identified.
Graphical abstract
Highlights
A novel method of pre-column derivatization with
dansyl chloride followed by analysis of ultra high-performance liquid
chromatographic–tandem mass spectrometry (UHPLC–MS/MS) was established and
validated for quantification of bakuchiol in rat plasma. The intravenous and
oral pharmacokinetic profiles of bakuchiol were obtained by utilizing the
established method. ► An UHPLC–MS/MS method with
pre-column derivatization was built for bakuchiol. ► The method demonstrated
high sensitivity, wide linear range and short runtime. ► The method was used to
explore the pharmacokinetic profile of bakuchiol in rats. ► The oral
bioavailability of bakuchiol (3.2%) was reported for the first
time.
5 March 2013 Publication year:
2013 Source:Journal of Pharmaceutical and Biomedical Analysis, Volume
75
Over the last two decades, a growing number of scientific evidences
highlighted the potential therapeutic value of several structures of
aminoglycoside antibiotics (including gentamicin and G418) for the treatment of
various genetic diseases caused by nonsense mutations. These findings resulted
in a fast evolvement of synthetic derivatives of aminoglycosides which were
shown to be more target specific and less toxic than the clinically used
antibiotics. The emerging progress in drug design and development has
necessitated the urge to develop a fast, easy and accurate procedure for the
determination of these potential therapeutic agents in various biologically
derived matrices. Here we describe the preparation of a generic polyclonal
antibody that was used for the development of homologous and heterologous
immunoassays for the detection of a wide range of natural and synthetic
aminoglycoside derivatives, highlighted today as potential therapeutic agents
for the treatment of various genetic diseases. A common two-ring scaffold, NB82,
present in the majority of compounds exhibiting potent biological activity, was
used as a generic immunization hapten for the immunization of two rabbits. By
using a series of chemical steps, NB82 was selectively conjugated via the N-1
position through glutaric acid linker to a carrier protein. Sensitivity (I 50)
values for the recognition of three representative compounds NB82, NB84 and
NB124 were determined to be 10±3ngmL−1, 0.5±0.04μgmL−1 and
1±0.12μgmL−1, respectively. Limits of detection were determined to be
1±0.3ngmL−1 for NB82, 20±7ngmL−1 for NB84 and
15±8ngmL−1 for NB124. The developed assays were further exploited for
the in vivo monitoring of the therapeutic compounds in mice serum. Serum
experimentations exhibited similar detection limits as observed for the PBS
calibration experiments, demonstrating no interference with assays sensitivity,
with rather high recovery ratios ranging from 92 to 107% in whole blood samples.
Graphical abstract
Highlights
► A broad-specific ELISA
for the detection of aminoglycosides with 6′-OH was developed. ► These 6′-OH
aminoglycosides are best candidates for the treatment of genetic diseases. ► A
two-ring scaffold was selectively conjugated to a carrier protein at N-1
position. ► A generic antibody allowed highly sensitive monitoring of
therapeutic agents in vivo. ► The assay will aid in further development of
therapeutic compounds in clinic.
5 March 2013 Publication year:
2013 Source:Journal of Pharmaceutical and Biomedical Analysis, Volume
75
The metabolites and pharmacokinetics of ganoderic acid C2 (GAC2), a
bioactive triterpenoid in Ganoderma lucidum in rat plasma were investigated by
high-performance liquid chromatography coupled with electrospray ionization
tandem mass spectrometry (HPLC–ESI-MS/MS). Totally, ten minor phase I
metabolites of GAC2 were characterized after oral administration of GAC2, on the
basis of their mass fragmentation pathways or direct comparison with authentic
compounds by high-performance liquid chromatography coupled with diode array
detection and electrospray ion trap tandem mass spectrometry
(HPLC–DAD–ESI-MS n ), and liquid chromatography coupled with
electrospray ionization hybrid ion trap and time-of-flight mass spectrometry
(LC–ESI-IT-TOF/MS) methods. Moreover, a rapid and specific method for
quantification of GAC2 in rat plasma after oral administration was developed by
using a liquid–liquid extraction procedure and HPLC–ESI-MS/MS analysis. It is
the first time to report the metabolites and pharmacokinetics of GAC2.
Graphical abstract
Highlights
Proposed metabolic pathways of ganoderic acid C2
(M0) in rats. ► Ten minor phase I metabolites were
characterized. ► A rapid quantification method was developed by LC–MS/MS. ► The
metabolites and pharmacokinetic of GAC2 were reported firstly.
No comments:
Post a Comment