A rapid and sensitive liquid chromatography/tandem mass spectrometry method for determination of docetaxel in human plasma

A novel, rapid and sensitive isocratic liquid chromatography/tandem mass spectrometry (LC/MS/MS) method was developed for quantification of docetaxel in human plasma with paclitaxel as internal standard. The high sensitivity and specificity of MS/MS detection enabled the use of a small volume of plasma (0.05 mL) and a simple liquid-liquid extraction procedure. Furthermore, a very short run-time (3 min) fulfilled the need for monitoring plasma levels of docetaxel from large-scale clinical studies. The calibration curve for docetaxel was linear over the range 5-1000 ng/mL with coefficients of correlation >0.999 using only 0.05 mL plasma. The intra- and inter-day precisions (CV) of analysis were <7%, and accuracy ranged from 96 to 110%. The applicability of the method was demonstrated in a pharmacokinetic study of a 1-h infusion of docetaxel with dosages of 75 mg/m(2). Possible conjugated metabolites of docetaxel were not detected in patients' samples.     

Unlabeled trees: Distribution of the maximum degree

Pick a tree uniformly at random from among all unlabeled trees on n vertices, and let X_n be the maximum of the degrees of its vertices. For any fixed integer d, as n→∞, where μ_n = c₁ log n, where {μ_n} : = μ_n – ?μ? denotes the fractional part of μ_n and where c_o, c₁, and η_∞ are knnown constants, givenb approximately by c₀ = 3.262 …, c₁ = 0.9227 …, and η_∞ = 0.3383…. © 1994 John Wiley & Sons, Inc.     

Identification of a serine protease inhibitor homologue in Bird's Nest by an integrated proteomics approach.

For centuries, the edible nests of Collocalia spp. ("Bird's Nests") have been used as a Chinese delicacy that had been claimed to be an effective health-giving tonic. However, clinical studies indicated that in Singapore, Bird's Nest is the most common cause of food-induced anaphylaxis in children, which could lead to potentially life-threatening allergenic reactions. The purpose of this study was to characterize the major allergens in Bird's Nest by using the combined technologies of two-dimensional gel electrophoresis (2-DE), immunochemistry, N-terminal protein sequencing, and mass spectrometry. Results from the immunostaining of the Western blots of the Bird's Nest 2-DE separated proteins with the sera from allergic patients indicated the presence of a major allergen of 66 kDa. Initial searches of the matrix assisted laser desorption/ionization--time of flight--mass spectrometry (MALDI-TOF-MS) tryptic peptide masses of the allergen in the SWISS-PROT and NCBI nonredundant databases revealed that this protein was novel. Based on the partial protein sequence information obtained from N-terminal microsequencing and nanoelectrospray-tandem MS, the 66 kDa immunoreactive allergen was found to be homologous to ovoinhibitor, a Kazal-type serine protease inhibitor, which is one of the dominant allergens found in chicken egg white.     

Separation of kaempferols in Impatients balsamina flowers by capillary electrophoresis with electrochemical detection

Capillary electrophoresis with wall-jet amperometric detection was used to detect kaempferol and its derivatives kaempferol-3-glucoside, kaempferol-3-glucosylrhamnoside and kaempferol-3-(p-coumaroyl)glucoside. The influence of buffer pH on separation was investigated and optimized. With a phosphate buffer at pH 7.5, nearly complete separation of the four kaempferols was achieved according to their different electrophoretic mobilities. The detection potential was also evaluated and optimized. At detection potential of +0.80 V vs. saturated calomel electrode, an amperometric response with high sensitivity and stability was obtained for these four compounds. Detection limit estimated for all the kaempferols examined was less than 1.4 fmol, based on S/N=3. The use of this method for the separation and detection of these compounds present in balsam flowers (Impatiens balsamina) is reported.     

An efficient lactamization of fimbrolides to novel 1,5-dihydropyrrol-2-ones

A new versatile method for the conversion of fimbrolides to the corresponding novel dihydropyrrol-2-ones is described. This new efficient lactamization protocol has the advantage of higher yields and can be used for the synthesis of a series of new dihydropyrrol-2-ones with interesting anti-bacterial properties.     

Polymerization behavior of 1,2,2,6,6-pentamethyl-4-piperidinyl m-isopropenyl-α,α-dimethylbenzyl carbamate

Copolymers of 1,2,2,6,6-pentamethyl-4-piperidinyl m-isopropenyl-α,α-dimethylbenzyl carbamate (CB) with styrene (S) and with methyl methacrylate (MMA) were synthesized using AIBN as initiator. S–CB copolymers made from feed ranging from 0.45–0.94 mole fractions S and MMA-CB copolymers made from feed of 0.34–0.88 mole fractions MMA were used to determine the monomer reactivity ratios r₁ and r₂. The structure of S–CB copolymers was inferred to be mainly of a random nature and in the MMA–CB copolymerization system there is a stronger tendency to form alternating copolymers. © 1993 John Wiley & Sons, Inc.     

Gas chromatography—mass spectrometry analysis of termite defence secretions in the subfamilyNasutitermitinae

Summary Mono- and diterpenoid components of severalNasutitermitinae soldier secretions have been characterised by gas chromatographymass spectrometry. Patterns in monoterpene distribution are useful, but not sufficient for chemotaxonomic purposes without determination of the diterpene distribution. Diterpenoids are structurally complex and can have tetracyclic, tricyclic and bicyclic skeletal structures with various degrees of oxygenation. The relative retention indices for several identified diterpenoid compounds have been determined on OV-1 and OV-17 columns. The amount and distribution of the terpenoid components are useful aids to chemotaxonomy forNasutitermitinae termites.

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Gaschromatographisch-massenspektrometrische Analyse der Verteidigungs-Sekrete der Termiten-Subfamilie Nasutitermitinae

Zusammenfassung Mono- und Diterpenderivate in den Sekreten verschiedenerNasutitermitinae-Soldaten wurden mit Hilfe der Gaschromatographie-Massenspektro-metrie charakterisiert. Verteilungsmuster der Monoterpene sind nützlich, aber für chemotaxonomische Zwecke ohne Bestimmung der Diterpen-Verteilung nicht ausreichend. Diterpenabkömmlinge sind in struktureller Hinsicht komplex und haben tetracyklische, tricyklische und bicyklische Strukturen mit wechselndem Sauerstoffgehalt. Die relativen Retentionsindices für einzelne identifizierte Diterpenabkömmlinge wurden auf OV-1- und OV-17-Säulen bestimmt. Menge und Verteilung der Terpenabkömmlinge sind nützliche Hilfsmittel für die Chemotaxonomie der genannten Termiten.

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Presented at the 8th International Microchemical Symposium, Graz, August 25–30, 1980.     

Further study on the prediction of isothermal induction time by dynamic differential scanning calorimetry

To test the applicability of dynamic DSC for predicting isothermal oxidation induction time, further study was carried out on butadiene rubber samples. Similar to the natural rubber samples, various Arrhenius plots of the butadiene rubber samples could be superimposed to form a single plot using a shift factor dependent on the oxidation peak temperature obtained from a dynamic DSC test. The superimposed plot can then be used to predict the oxidation induction times of other butadiene rubber samples from dynamic DSC test results.     

Miscibility and specific interactions in polyacrylonitrile/ poly(p‐vinylphenol) blends

A rare miscible polyacrylonitrile (PAN) blend system is reported. PAN is miscible with poly(p‐vinylphenol) (PVPh) as shown by thermal and spectroscopic studies. A single glass transition temperature was found in each blend. Infrared spectroscopic studies showed that the hydroxyl band of PVPh and the cyano band of PAN shifted to lower frequencies upon blending, showing the existence of specific interactions between the two polymers. The involvement of cyano groups in specific interactions was further evidenced by the development of a high‐binding‐energy N1s peak in each blend from X‐ray photoelectron spectroscopic studies.     

Coriandrum sativum L.: A Review on Ethnopharmacology,Phytochemistry, and Cardiovascular Benefits

Coriandrum sativum (C. sativum), belonging to the Apiaceae (Umbelliferae) family, is widely recognized for its uses in culinary and traditional medicine. C. sativum contains various phytochemicals such as polyphenols, vitamins, and many phytosterols, which account for its properties including anticancer, anti-inflammatory, antidiabetic, and analgesic effects. The cardiovascular benefits of C. sativum have not been summarized before, hence this review aims to further evaluate and discuss its effectiveness in cardiovascular diseases, according to the recent literature. An electronic search for literature was carried out using the following databases: PubMed, Scopus, Google Scholar, preprint platforms, and the Cochrane Database of Systematic Reviews. Articles were gathered from the inception of the database until August 2021. Moreover, the traditional uses and phytochemistry of coriander were surveyed in the original resources and summarized. As a result, most of the studies that cover cardiovascular benefits and fulfilled the eligibility criteria were in vivo, while only a few were in vitro and clinical studies. In conclusion, C. sativum can be deemed a functional food due to its wide range of cardiovascular benefits such as antihypertensive, anti-atherogenic, antiarrhythmic, hypolipidemic as well as cardioprotective effects.