scholarly journals Accurate Identification of Degraded Products of Aflatoxin B1 Under UV Irradiation Based on UPLC-Q-TOF-MS/MS and NMR Analysis

2021 ◽  
Vol 9 ◽  
Author(s):  
Yan-Duo Wang ◽  
Cheng-Gang Song ◽  
Jian Yang ◽  
Tao Zhou ◽  
Yu-Yang Zhao ◽  
...  
Keyword(s):  
Uv Irradiation ◽  
Integrated Approach ◽  
Structural Features ◽  
Nmr Analysis ◽  
Purification And Characterization ◽  
Accurate Identification ◽  
Mycotoxin Degradation ◽  
Biological Tests ◽  
Tof Ms

Analysis, purification, and characterization of AFB1 degraded products are vital steps for elucidation of the photocatalytic mechanism. In this report, the UPLC-Q-TOF-MS/MS technique was first coupled with purification and NMR spectral approaches to analyze and characterize degraded products of AFB1 photocatalyzed under UV irradiation. A total of seventeen degraded products were characterized based on the UPLC-Q-TOF-MS/MS analysis, in which seven ones (1–7) including four (stereo) isomers (1,2, 5, and 6) were purified and elucidated by NMR experiments. According to the structural features of AFB1 and degraded products (1–7), the possible photocatalytic mechanisms were suggested. Furthermore, AFB1 and degraded products (1–7) were evaluated against different cell lines. The results indicated that the UPLC-Q-TOF-MS/MS technique combined with purification, NMR spectral experiments, and biological tests was an applicable integrated approach for analysis, characterization, and toxic evaluation of degraded products of AFB1, which could be used to evaluate other mycotoxin degradation processes.

PURIFICATION AND CHARACTERIZATION OF DONKEY CHORIONIC GONADOTROPHIN

1980 ◽  
Vol 85 (3) ◽  
pp. 449-455 ◽  
Author(s):  
B. B. AGGARWAL ◽  
SUSAN W. FARMER ◽  
HAROLD PAPKOFF ◽  
FRANCESCA STEWART ◽  
W. R. ALLEN
Keyword(s):  
Amino Acid ◽  
Leydig Cell ◽  
Seminiferous Tubule ◽  
Chorionic Gonadotrophin ◽  
Purification And Characterization ◽  
Rat Testis ◽  
Amino Terminal ◽  
Biological Tests

Serum of the pregnant donkey, like that of the mare, contains a gonadotrophin of chorionic origin. The chorionic gonadotrophin of the donkey (dCG) has been isolated in purified form from the serum of pregnant donkeys using methodology previously employed for the purification of pregnant mare chorionic gonadotrophin (eCG). Unlike eCG, dCG is predominantly an LH in biological tests. In the in-vitro rat Leydig cell assay, dCG was as active as eCG, but in the in-vitro rat seminiferous tubule assay for FSH and in the augmentation assay, dCG was considerably less potent than eCG (1–10%). Specific rat testis radioreceptor assays for LH and FSH also showed dCG to be at least nine times more potent in LH than in FSH activity. Chemically, dCG was found to be similar to eCG in fractionation behaviour and glycoprotein nature. However, dCG had significantly less carbohydrate (31%) than had eCG (45%) and several differences were noted in a comparison of amino-acid compositions. A single amino-terminal residue, phenylalanine, was detected in dCG. Immunologically, dCG cross-reacted in homologous radioimmunoassays for eCG, equine LH and equine FSH, but its inhibition curves were all non-parallel with those of the respective equine gonadotrophin standards.

scholarly journals Purification and Identification of Novel Antioxidant Peptides Isolated from Geoffroea decorticans Seeds with Anticoagulant Activity

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1153
Author(s):  
Juliana Cotabarren ◽  
Brenda Ozón ◽  
Santiago Claver ◽  
Javier Garcia-Pardo ◽  
Walter David Obregón
Keyword(s):  
Anticoagulant Activity ◽  
Structural Features ◽  
Deciduous Tree ◽  
Antioxidant Peptides ◽  
Purification And Characterization ◽  
Molecular Weights ◽  
Ic50 Value ◽  
Dose Dependent ◽  
Direct Applicability

Geoffroea decorticans is a xerophilous deciduous tree present in most arid forests of southern South America, which is commonly used in traditional medicine. The seeds of this tree have been previously investigated for their singular chemical composition, but their protein content has been poorly investigated. Herein, we report the isolation, purification, and characterization of a set of thermostable peptides derived from Geoffroea decorticans seeds (GdAPs) with strong antioxidant and anticoagulant activities. The most potent antioxidant peptides showed a half maximal inhibitory concentration (IC50) of 35.5 ± 0.3 µg/mL determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH). They also caused a dose-dependent prolongation of the aPTT clotting time with an IC50 value of ~82 µg/mL. Interestingly, MALDI-TOF/MS analysis showed the presence of three major peptides with low molecular weights of 2257.199 Da, 2717.165 Da, and 5422.002 Da. The derived amino-acid sequence of GdAPs revealed their unique structural features, exhibiting homology with various proteins present in the genome of Arachis hypogaea. All in all, our data suggest a direct applicability of GdAPs for pharmaceutical purposes.

Skeletal elements of crinoid echinoderms: High-resolution structural and microanalytical results

1983 ◽  
Vol 41 ◽  
pp. 194-195
Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor
Keyword(s):  
High Resolution ◽  
Marine Invertebrates ◽  
Sea Urchins ◽  
Structural Features ◽  
Sea Stars ◽  
High Resolution Tem ◽  
Relationship Of ◽  
The Relationship ◽  
Insight Into

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.

Ultrastructural identification of three types of sensory setae on copepod antennae

1995 ◽  
Vol 53 ◽  
pp. 956-957
Author(s):  
T. M. Weatherby ◽  
P.H. Lenz
Keyword(s):  
Phase Locking ◽  
Membrane Surface ◽  
Reaction Times ◽  
High Sensitivity ◽  
Structural Features ◽  
Calanoid Copepods ◽  
Marine Food Webs ◽  
Dendritic Membrane ◽  
Ultrastructural Characterization

Crustaceans, as well as other arthropods, are covered with sensory setae and hairs, including mechanoand chemosensory sensillae with a ciliary origin. Calanoid copepods are small planktonic crustaceans forming a major link in marine food webs. In conjunction with behavioral and physiological studies of the antennae of calanoids, we undertook the ultrastructural characterization of sensory setae on the antennae of Pleuromamma xiphias.Distal mechanoreceptive setae exhibit exceptional behavioral and physiological performance characteristics: high sensitivity (<10 nm displacements), fast reaction times (<1 msec latency) and phase locking to high frequencies (1-2 kHz). Unusual structural features of the mechanoreceptors are likely to be related to their physiological sensitivity. These features include a large number (up to 3000) of microtubules in each sensory cell dendrite, arising from or anchored to electron dense rods associated with the ciliary basal body microtubule doublets. The microtubules are arranged in a regular array, with bridges between and within rows. These bundles of microtubules extend far into each mechanoreceptive seta and terminate in a staggered fashion along the dendritic membrane, contacting a large membrane surface area and providing a large potential site of mechanotransduction.

Quantitative nano-characterization of heterogeneous catalysts

1995 ◽  
Vol 53 ◽  
pp. 398-399
Author(s):  
P.A. Crozier ◽  
M. Pan
Keyword(s):  
Heterogeneous Catalysts ◽  
Low Dose ◽  
Imaging Techniques ◽  
Structural Features ◽  
Catalyst Characterization ◽  
New Developments ◽  
Double Phase ◽  
Phase Systems ◽  
Dose Imaging

Heterogeneous catalysts can be of varying complexity ranging from single or double phase systems to complicated mixtures of metals and oxides with additives to help promote chemical reactions, extend the life of the catalysts, prevent poisoning etc. Although catalysis occurs on the surface of most systems, detailed descriptions of the microstructure and chemistry of catalysts can be helpful for developing an understanding of the mechanism by which a catalyst facilitates a reaction. Recent years have seen continued development and improvement of various TEM, STEM and AEM techniques for yielding information on the structure and chemistry of catalysts on the nanometer scale. Here we review some quantitative approaches to catalyst characterization that have resulted from new developments in instrumentation.HREM has been used to examine structural features of catalysts often by employing profile imaging techniques to study atomic details on the surface. Digital recording techniques employing slow-scan CCD cameras have facilitated the use of low-dose imaging in zeolite structure analysis and electron crystallography. Fig. la shows a low-dose image from SSZ-33 zeolite revealing the presence of a stacking fault.

Purification and characterization of phosphoglucomutase from peas

1994 ◽  
Vol 92 (3) ◽  
pp. 479-486 ◽  
Author(s):  
Cynthia M. Galloway ◽  
W. Mack Dugger
Keyword(s):  
Purification And Characterization

Purification and Characterization of Tissue-Type Plasminogen Activator in Maxillary Mucosa with Chronic Inflammation

1985 ◽  
Vol 54 (02) ◽  
pp. 485-489 ◽  
Author(s):  
Yukiyoshi Hamaguchi ◽  
Masuichi Ohi ◽  
Yasuo Sakakura ◽  
Yasuro Miyoshi
Keyword(s):  
Plasminogen Activator ◽  
Chronic Inflammation ◽  
Gel Filtration ◽  
Potassium Acetate ◽  
Tissue Type ◽  
Purification And Characterization ◽  
Tissue Type Plasminogen Activator ◽  
Urokinase Inhibitor ◽  
Type Plasminogen Activator

SummaryTissue-type plasminogen activator (TPA) was purified from maxillary mucosa with chronic inflammation and compared with urokinase. Purification procedure consisted of the extraction from delipidated mucosa with 0.3M potassium acetate buffer (pH 4.2), 66% saturation of ammonium sulfate, zinc chelate-Sepharose, concanavalin A-Sepharose and Sephadex G-100 gel filtration chromatographies.The molecular weight of the TPA was approximately 58,000 ± 3,000. Its activity was enhanced in the presence of fibrin and was quenched by placental urokinase inhibitor, but not quenched by anti-urokinase antibody. The TPA made no precipitin line against anti-urokinase antibody, while urokinase did.All these findings indicate that the TPA in maxillary mucosa with chronic inflammation is immunologically dissimilar to urokinase and in its affinity for fibrin.

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