Affinity protocols for the purification of urinary trypsin inhibitor (UTI) were developed. To imitate the substrate/inhibitor-binding domain (S1 domain) of trypsin and chymotrypsin, the key amino acid residues were composed to sorbents. The sorbents were then subjected to adsorption analysis with UTI. The purification process consisted of one step of affinity chromatography and another step of ultrafiltration. The purified enzyme was subjected to SDS-PAGE, trypsin inhibitor activity and peptide map fingerprinting analysis. As calculated, the theoretical maximum adsorption (Q(max)) of two affinity sorbents entitled as S-D-G and S-S-G were 31.7 and 30.1 mg/g, respectively; the desorption constants K(d) of the two sorbents were 8.9 and 18.6 μg/mL, respectively. After the separation of UTI with S-D-G and S-S-G, reducing SDS-PAGE analysis revealed that the protein was a single polypeptide with the mass of ~66 kDa, and the purified proteins were ~95 and 97% pure, respectively; the band on gel was further confirmed with peptide map fingerprinting analysis. Protein and bioactivity recoveries were 1.3 and 75.9% with S-D-G, 1.0 and 70.2% with S-S-G, respectively.
[Show abstract][Hide abstract] ABSTRACT: The development of simple, rapid and solvent-free methods for the analysis of essential oils is highly desirable. Microwave-assisted headspace solid-phase microextraction (MA-HS-SPME) is a new sampling and concentration technique for the extraction of volatile components in medicinal plants. The main advantages of this method are the reduction of extraction time and of organic solvent.
A highly porous Santa Barbara amorphous (SBA-15)/polyaniline material was prepared in order to produce a SPME fibre. The proposed fibre was evaluated for the extraction of the volatile component of Teucrium polium L.
A homemade MA-HS-SPME apparatus was used for the extraction of volatile components. Highly porous SBA-15/polyaniline materials were prepared for SPME. The prepared nanomaterial was immobilized onto a stainless steel wire for fabrication of the SPME fibre.
The SBA-15/polyaniline nanonporous fibre could adsorb volatile components of T. polium efficiently. In comparison with a HD method, the proposed technique could equally monitor almost all the components of the sample, but in an easier way that was rapid and required a much lower amount of sample.
The experimental results showed that the nanoporous fibre was suitable for the semi-quantitative study of the composition of essential oils in plant materials and monitoring the variations in the volatile components of the plants. Copyright
[Show abstract][Hide abstract] ABSTRACT: The Stockholm Convention (SC) on Persistent Organic Pollutants (POPs) is a global treaty under the United Nation Environmental Program with the aims to protect human health and the environment from hazardous, long-lasting chemicals through a series of activities to reduce and ultimately to eliminate their release.To assess the effectiveness of these activities undertaken worldwide, the Global Monitoring Plan was established in a bid to obtain comparable monitoring data on distribution of POPs, to identify changes in concentration over time, and to provide information on their regional and global environmental transport. Over 10 years after the adoption of the SC, new or improved techniques have been developed to strengthen the measurement capabilities of the parties to the SC.This article reviews the literature published in 2008–12 on the analysis of 22 POPs under the SC, covering recent development in sample preparation, separation, and detection in analysis of POPs.
[Show abstract][Hide abstract] ABSTRACT: An efficient affinity purification protocol for Bacillus monomeric sarcosine oxidase expressed in Escherichia coli BL21 (DE3) was developed. 4-Aminopyrrole-2-carboxylic acid was chosen as the affinity ligand, which was coupled with Sepharose CL 4B via spacers composed of epichlorohydrin and ethylenediamine. With the affinity medium, the purification process consisted of only one affinity chromatography step to capture monomeric sarcosine oxidase. The purified sarcosine oxidase was 94 and 96% pure analyzed on an HPLC Vydac C8 column and reducing SDS-PAGE. Meanwhile, the recoveries of typical sarcosine oxidase activity and protein were 90.8 and 37.5%, respectively, which were higher than other reported traditional protocols. Reducing SDS-PAGE analysis revealed that the enzyme was a single polypeptide with the mass of ～46 kDa. The desorption constant Kd and theoretical maximum absorption Qmax were 35 μg/mL and 52.7 mg/g, respectively, in absorption analysis. All results indicated that the method would be of great potential for purifying monomeric sarcosine oxidase on an industrial scale. This article is protected by copyright. All rights reserved.
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