National Organization for Drug Control and Research, Cairo University
Abstract
Stability-indicating reversed-phase high-performance liquid chromatography (RP-HPLC) and normal-phase high-performance thin-layer chromatography (NP-HPTLC) methods have been developed for the determination of palonosetron which is a potent antiemetic drug used with chemotherapy. Forced degradation studies were performed on palonosetron to study its stability behavior. The drug was subjected to acid, base, neutral hydrolysis, oxidation, thermal and photolytic conditions. Mass analysis has been performed to elucidate the oxidative degradants by Advion compact mass spectrometer. HPLC separation was achieved on PerfectChrom 100 C4 (250 × 4.6 mm, 5 μm particle size) column using buffer (20 mM dipotassium hydrogen orthophosphate, adjusted with phosphoric acid to pH 2.5):acetonitrile:methanol (60:30:10, v/v) as the mobile phase with isocratic mode at a flow rate of 1 mL/min using photodiode array detector (PAD) at 210 nm. The method showed adequate sensitivity concerning linearity, accuracy and precision over the range of 0.1–10 μg/mL. Limit of detection (LOD) and limit of quantification (LOQ) were determined to be 0.03 μg/mL and 0.09 μg/mL, respectively. HPTLC separation was carried out on aluminum plates pre-coated with silica gel 60 F254 using methanol:ammonia (10:0.5, v/v) as the mobile phase. CAMAG scanner was operated at 254 nm for the densitometric measurement in the absorbance mode. A polynomial relationship was constructed in concentration range of 0.1–2 μg/band, with LOD and LOQ 0.02 μg/band and 0.06 μg/band, respectively. The cited chromatographic methods were successfully applied to the determination of palonosetron in the presence of its degradation products and additives in the commercially available vials. Method validation was performed as per the ICH guidelines confirming methods robustness to be used in quality control laboratories. Statistical comparisons have been performed between the results of the cited chromatographic methods and those of the official one using Student’s ttest and F test values at 95% confidence interval level, revealing good accuracy and precision.
Authors: Japan Bioindustry Association, Advanced Industrial Science and Technology, Japan
Highlights
Deacetylation of glycopeptide with an esterase prevents base-induced side reactions, b-elimination, and epimerization
An esterase from B. subtilis was utilized for Deacetylation of sugar hydroxyl groups on glycopeptide synthesis
Deacetylation with an esterase and glycosylations with glycosyltransferases were accomplished in one-pot
Abstract
Glycopeptides are fragments of glycoproteins and are important in evaluating the biological roles of carbohydrates in glycoproteins. Fmoc solid-phase peptide synthesis using acetyl-protected glycosylated amino acids is a common strategy for the preparation of glycopeptides, but this approach normally requires chemical de-O-acetylation with a base that β-eliminates sugar residues and epimerizes the peptide backbone. Here we demonstrate a facile new chemoenzymatic synthetic strategy for glycopeptides, using an esterase for the de-O-acetylation of sugar residues and glycosyltransferases for successive sugar elongations at neutral pH.
ESI-MS spectra were collected using an Advion expression Compact Mass Spectrometer (CMS) in negative ion mode.
Learn Mass Spectrometry: For a limited time, access our free curriculum from Dr. Jack Henion, global leader and educator for Mass Spectrometry and LC/MS
Take advantage of this educational opportunity to learn from the master, Dr. Henion, Cornell Emeritus Professor, who will guide you through basic principles to more advanced techniques. This lecture series offers a university-level course, only offered to Advion customers and university students — until now.
This lecture package includes the following modules:
Introduction to Mass Spectrometry
Flow Injection Analysis, ESI and APCI Ionization Techniques
Direct Analysis Probe for Liquids and Solids (ASAP)
Plate Express TLC Plate Reader
Touch Express Open Port Sampling Interface (OPSI)
LC/MS Techniques
Other CMS Applications & Techniques
This course is available for a limited time to aid in at-home learning initiatives and coursework. Professors who aim to teach, undergraduates who desire to further their education, or Ph.D.’s in need of a refresher, our team at Advion is offering this package at no-charge.
Advion’s curriculum package offers viewers a wide range of essentials for teaching and learning mass spectrometry for chemists.
Benzo[d]thiazole is widely used in synthetic and medicinal chemistry, and it is a component of many compounds and drugs that have several different bioactivities. Herein, we describe an elegant pathway for synthesis of methyl 4- and 5-hydroxy-2-amino-benzo[d]thiazole-6-carboxylates as building blocks that can be substituted at four different positions on the bicycle and thus offer the possibility to thoroughly explore the chemical space around the molecule studied as a ligand for the chosen target. A series of 12 new compounds was prepared using the described methods and Williamson ether synthesis.
Martin-Luther-University Halle-Wittenberg, Free University of Berlin
Abstract
Cannabis products have been used in various fields of everyday life for many centuries, and applications in folk medicine and textile production have been well-known for many centuries. For traditional textile production, hemp fibers were extracted from the stems by water retting in stagnant or slow-moving waters.
During this procedure, parts of the plant material‚ among them phytocannabinoids‚ are released into the water. Cannabinol (CBN) is an important degradation product of the predominant phytocannabinoids found in Cannabis species. Thus, it is an excellent indicator for present as well as ancient hemp water retting.
In this study, we developed and validated a simple and fast method for the determination of CBN in sediment samples using high-performance thin-layer chromatography (HPTLC) combined with electrospray ionization mass spectrometry (ESI-MS), thereby testing different extraction and cleanup procedures‚ as well as various sorbents and solvents for planar chromatography.
This method shows a satisfactory overall analytical performance with an average recovery rate of 73%. Our protocol enabled qualitative and quantitative analyses of CBN in samples of a bottom sediment core‚ having been obtained from a small lake in Northern India, where intense local retting of hemp was suggested in the past. The findings correlate with existing records of Cannabis-type pollen. Thus, the method we propose is a helpful tool to track ancient hemp retting activities.
The Advion TLC/CMS system with the expression® Compact Mass Spectrometer (CMS) and Plate Express® TLC Plate Reader was utilized for the elution of compounds from the HPTLC plates.
The recent outbreak of severe lung injury is allegedly tied to the presence of Vitamin E Acetate (VEA) in vaping-related products after VEA was found in lung fluid samples of patients with vaping-related lung illness (EVALI). Calling for regulatory control, Washington, Colorado and Ohio have already banned the use of VEA in e-juices at the state level.
The Advion Interchim Scientific expression® Compact Mass Spectrometer (CMS) with the Atmospheric Solids Analysis Probe (ASAP®) provides a highly sensitive screening method for the presence of VEA.
In this Lab Manager webinar, Dr. Daniel Eikel, Advion Director of Product Applications and Customer Service reviews the use of the Advion expression Compact Mass Spectrometer (CMS) for food and beverage analysis.
As an attendee, you will learn more about:
How leading technologies and techniques affect food science researchers
How to establish workflows that optimize the efficiency of your food science lab
New and novel applications in the field of food and beverage science
The discovery of chemical reactions is an inherently unpredictable and time-consuming process. An attractive alternative is to predict reactivity, although relevant approaches, such as computer-aided reaction design, are still in their infancy. Reaction prediction based on high-level quantum chemical methods is complex, even for simple molecules. Although machine learning is powerful for data analysis, its applications in chemistry are still being developed6. Inspired by strategies based on chemists’ intuition, we propose that a reaction system controlled by a machine learning algorithm may be able to explore the space of chemical reactions quickly, especially if trained by an expert. Here we present an organic synthesis robot that can perform chemical reactions and analysis faster than they can be performed manually, as well as predict the reactivity of possible reagent combinations after conducting a small number of experiments, thus effectively navigating chemical reaction space. By using machine learning for decision making, enabled by binary encoding of the chemical inputs, the reactions can be assessed in real time using nuclear magnetic resonance and infrared spectroscopy.
Constructive machine learning aims to create examples from its learned domain which are likely to exhibit similar properties. Here, a recurrent neural network was trained with the chemical structures of known cell‐migration modulators. This machine learning model was used to generate new molecules that mimic the training compounds. Two top‐scoring designs were synthesized, and tested for functional activity in a phenotypic spheroid cell migration assay. These computationally generated small molecules significantly increased the migration of medulloblastoma cells. The results further corroborate the applicability of constructive machine learning to the de novo design of druglike molecules with desired properties.
Analysis was performed by TLC/MS using the Advion expression Compact Mass Spectrometer (CMS) and Plate Express TLC Plate Reader.
USDA Cornell University, Federal University of Viçosa
Abstract
This study assessed and compared the effects of the intra-amniotic administration of various concentrations of soluble extracts from chia seed (Salvia hispanica L.) on the Fe and Zn status, brush border membrane functionality, intestinal morphology, and intestinal bacterial populations, in vivo. The hypothesis was that chia seed soluble extracts will affect the intestinal morphology, functionality and intestinal bacterial populations…This study demonstrated that the intra-amniotic administration of chia seed soluble extracts increased (p < 0.05) the villus surface area, villus length, villus width and the number of goblet cells. Further, we observed an increase (p < 0.05) in zinc transporter 1 (ZnT1) and duodenal cytochrome b (Dcytb) proteins gene expression. Our results suggest that the dietary consumption of chia seeds may improve intestinal health and functionality and may indirectly improve iron and zinc intestinal absorption.
Analysis was performed by LC/MS using the Advion expression Compact Mass Spectrometer (CMS).
