Part No: P150Issued year: 2016File size: 0.39mbFile type: pdf
Interest in peptide-based therapeutics has risen dramatically over the last decade. More specifically, significant energy has been dedicated to cyclic peptides, their synthesis, their biological activity, and their biological stability as potential alternatives to their linear counterparts. However, synthesizing a cyclic peptide creates significant challenges not encountered in linear peptide synthesis.
Herein we present a synthesis of oxytocin describing optimization for fully automated, on-resin disulfide bond formation utilizing Branches™, a unique feature enabling visualization and specific programing for cyclic and branched peptide synthesis. We will highlight the transferability of this optimized synthesis to larger scale syntheses and conclude with the fully automated synthesis of cyclized oxytocin incorporating an isotopically labeled Leu residue, enabling use as an internal standard in MS experiments.
Part No: TN113Issued year: 2006File size: 0.09mbFile type: pdf
ISOLUTE Confirm HCX columns are based on cation exchange and C8 mixed mode chemistries. Basic drugs are therefore retained by two primary retention mechanisms - ionic and non-polar. This allows a more rigorous interference elution regime to be used, leading to a very clean final extract, as many non-polar interferences which are retained by a non-polar interaction alone, can be eluted selectively, prior to elution of the drug.
Part No: P024Issued year: 2008File size: 1.9mbFile type: pdf
It is well known that traditional liquid-liquid extraction (LLE) provides very clean extracts prior to LC/MS analysis. Supported liquid extraction is analogous to traditional LLE, however, analyte partitioning takes place using an inert support material, rather than two immiscible liquids. This provides excellent extraction efficiencies while alleviating many of the tedious liquid handling issues associated with LLE.
Part No: TN116Issued year: 2006File size: 0.07mbFile type: pdf
The extraction of basic drugs from biological fluids using a purely non-polar retention mechanism (e.g. C4, C8 or C18) can lead to extracts that contain a large amount of non-polar co-extracted material that can interfere with subsequent analysis. Conversely, extraction mechanisms based on ion exchange interactions can be non-robust due to the variable ionic strength of the sample matrix.
Part No: TN129Issued year: 2005File size: 0.07mbFile type: pdf
The use of ISOLUTE HCX mixed-mode sorbents is widely accepted for providing high purity extracts of basic drugs from biological fluids. The ISOLUTE HCX-Q sorbent utilizes a combination of weak cation exchange and C8 non-polar retention mechanisms.
Part No: Issued year: 2014File size: 1.02mbFile type: pdf
Testing for drugs of abuse in oral fluids can strongly benefit the criminal justice field as a less invasive and cost-effective approach for drug detection when compared to blood or urine sampling. Oral fluid analysis has facilitated laboratory analysis for many drugs of abuse and is a constantly evolving analysis procedure which benefits from increasingly sensitive methods of detection. The Laser Diode Thermal Desorption (LDTD) source combined with Mass spectrometry is presented as a new screening tool for drug analysis in Oral Fluids. Analysis speed of LDTD provides accurate results in seconds in combination with exceptional specificity of MS instruments make a powerful platform for the screening of different drugs of abuse and new emerging drugs. Different extraction procedures are available; however those methods depend on specific drug conditions: basic or acid drugs / hydrophilic or hydrophobic. A new extraction approach, Supported Liquid Extraction (SLE+) is evaluated as generic extraction procedure.
Part No: UI400Issued year: 2018File size: 0.11mbFile type: pdf
The tasks carried out during the Preventive Maintenance (PM)
visit shall include servicing the listed components and a final
check, which is based on factory acceptance and qualification
tests. These two procedures constitute a Gilson Preventive
Part No: AN056Issued year: 2012File size: 0.2mbFile type: pdf
Quinolines are an important class of broad-spectrum antibiotics1 that were traditionally obtained by refluxing an aniline and diethyl ethoxymethylemalonate (Scheme 1) for several hours often in low yield.2 Heating the reaction mixture by microwaves to temperatures above the boiling points, with or without solvents, improves the yields and shortens the reaction time dramatically.3-6
Part No: AN106Issued year: 2015File size: 0.3mbFile type: pdf
The term “Green Chemistry” has become a major part of the
science community’s lexicon. In this application note we will
look at two areas for flash chromatography:
1. Replacing chlorinated solvents with those considered more
2. Reducing solvent use and waste generation with more
thoughtfully applied chromatography principles.
Part No: P158Issued year: 2017File size: 0.27mbFile type: pdf
As reversed-phase flash chromatography gains traction in
medicinal chemistry labs the need to monitor its cost and
safety are becoming more important. Commonly used
reversed-phase solvents typically include water with an
organic solvent such as methanol or acetonitrile – each
have advantages and disadvantages.
Part No: AN801Issued year: 2003File size: 0.27mbFile type: pdf
The heat flow parameter can be used to monitor the progress of a reaction, and can be useful
in determining reaction rates. A heat flow probe study was executed on the Advantage
Series™ 3400 process chemistry workstation for the hydrolysis of acetic anhydride in water
at temperatures from 25 to 55 °C. The observed rate constant for the hydrolysis was determined
from the heat flow measurements. An Eyring plot was produced and the enthalpy and
entropy of activation were determined. Finally, the heat of reaction was measured based on
the total amount of heat that was observed during the hydrolysis.
Part No: AN036Issued year: 2001File size: 0.55mbFile type: pdf
Activated carbon is an adsorbent media used to remove colored compounds from solution. Using this media in the Biotage FLASH-AC cartridge as a packed bed improves adsorbent performance. Increasing the temperature of the solvent modifies adsorption and alters performance of the decolorization process. Elevated temperatures increase product solubility, therefore requiring less solvent than at room temperature. The increased concentration of product in a hot solution also simplifies crystallization.
Part No: AN040Issued year: 2003File size: 0.4mbFile type: pdf
Research in CNS drugs is primarily centered on nitrogen heterocycle chemistry. Basic amines are difficult to purify using traditional silica chromatography because of strong interactions between acidic silica and the molecules’ basic amine groups. These interactions cause band spreading and poor compound recovery. Solutions employed to counteract this phenomena include adding a competing amine (e.g. triethyl amine or ammonium hydroxide) to the flash chromatography solvent system or using reversed-phase HPLC with a buffered solvent system.
Part No: AN118-HOR.V.2Issued year: 2017File size: 1.33mbFile type: pdf
Hexane extractable material (HEM), also known as Oil & Grease extraction is a simple water quality measurement. The measurement can be used to assess pollution for compliance or as a measure of influent contamination to protect a waste treatment plant from levels that might cause malfunction.
Part No: P172Issued year: 2017File size: 0.49mbFile type: pdf
We investigate the use of reversed-phase high performance flash chromatography (HPFC) to quickly purify large quantities of crude synthetic peptides.
(6th Solid Phase Peptide Synthesis Symposium & 12th Australian Peptide Conference, Queensland, Australia, Oct. 2017)
Part No: Issued year: 2018File size: 0.66mbFile type: pdf
This poster presents a high sensitivity method for extraction and analysis of estrogens in human plasma. Sample preparation utilizes Biotage ISOLUTE SLE+ plates, providing high analyte recovery and low matrix effects.
MSACL 2018, Palm Spings, CA