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Rajarathnam E. Reddy - One of the best experts on this subject based on the ideXlab platform.
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transformation of vitamin b6 to Deoxypyridinoline a useful biochemical marker for diagnosis of bone diseases
Tetrahedron, 2000Co-Authors: Maciej Adamczyk, Srinivasa Rao Akireddy, Rajarathnam E. ReddyAbstract:Abstract A versatile chiral synthesis of the cross-link (+)-Deoxypyridinoline (Dpd, 2) was achieved starting from vitamin B6 (7). The key steps in the synthesis of (+)-2 are transformation of B6 (7) to the chloride (3d) and construction of three α-amino acid chains by utilizing (R)-(−)-Schollkopf's reagent (4), Wittig reagent (R)-(−)-5, and iodide (S)-(−)-6. (+)-Dpd (2) is a degradation product of bone collagen and has been found to be a useful marker for diagnosis of osteoporosis and other metabolic bone diseases.
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Synthesis of isotopically labeled (+)-Deoxypyridinoline
Journal of Labelled Compounds and Radiopharmaceuticals, 2000Co-Authors: Maciej Adamczyk, Donald D. Johnson, Rajarathnam E. Reddy, Sushil D. RegeAbstract:An efficient synthesis of isotopically labeled (+)-Deoxypyridinoline (3) was achieved via quaternization of (S,S)(−)-4 with (S)-(−)-iodide (5) and subsequent hydrolysis. The required (S)-(−)-iodide (5) was prepared from a commercially available (S)-5-(tert-butoxy)-4-[tert-butoxycarbonyl)amino]-5-oxopentanoic acid (6) in seven steps and good overall yield. Copyright © 2000 John Wiley & Sons, Ltd.
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Transformation of Vitamin B6 to (+)-Deoxypyridinoline, a useful Biochemical Marker for Diagnosis of Bone Diseases
Tetrahedron, 2000Co-Authors: Maciej Adamczyk, Srinivasa Rao Akireddy, Rajarathnam E. ReddyAbstract:Abstract A versatile chiral synthesis of the cross-link (+)-Deoxypyridinoline (Dpd, 2) was achieved starting from vitamin B6 (7). The key steps in the synthesis of (+)-2 are transformation of B6 (7) to the chloride (3d) and construction of three α-amino acid chains by utilizing (R)-(−)-Schollkopf's reagent (4), Wittig reagent (R)-(−)-5, and iodide (S)-(−)-6. (+)-Dpd (2) is a degradation product of bone collagen and has been found to be a useful marker for diagnosis of osteoporosis and other metabolic bone diseases.
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an efficient one pot synthesis of Deoxypyridinoline
Tetrahedron Letters, 1999Co-Authors: Maciej Adamczyk, Donald D. Johnson, Rajarathnam E. ReddyAbstract:Abstract An efficient one-pot synthesis of (+)-Deoxypyridinoline (Dpd, 1 ), the cross-link of bone collagen, was achieved from tert -butyl-( S )-(−)-[(2- tert -butoxycarbonyl)amino]-6-aminohexanoate ( 2 ) and tert -butyl-( S )-(−)-6-bromo-2-[bis( tert -butoxycarbonyl)amino]-5-oxohexanoate ( 3 ) in 42% yield.
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versatile synthesis of Deoxypyridinoline a biochemical marker for diagnosis of osteoporosis
Tetrahedron-asymmetry, 1999Co-Authors: Maciej Adamczyk, Srinivasa Rao Akireddy, Rajarathnam E. ReddyAbstract:Abstract A versatile chiral synthesis of the bone collagen cross-link, (+)-Deoxypyridinoline (Dpd, 1 ) was described starting from a 3-hydroxypyridine derivative ( 2 ) via sequential introduction of three amino acid chains followed by hydrolysis. The key synthon 2 , was prepared from vitamin B 6 ( 6 ).
Maciej Adamczyk - One of the best experts on this subject based on the ideXlab platform.
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transformation of vitamin b6 to Deoxypyridinoline a useful biochemical marker for diagnosis of bone diseases
Tetrahedron, 2000Co-Authors: Maciej Adamczyk, Srinivasa Rao Akireddy, Rajarathnam E. ReddyAbstract:Abstract A versatile chiral synthesis of the cross-link (+)-Deoxypyridinoline (Dpd, 2) was achieved starting from vitamin B6 (7). The key steps in the synthesis of (+)-2 are transformation of B6 (7) to the chloride (3d) and construction of three α-amino acid chains by utilizing (R)-(−)-Schollkopf's reagent (4), Wittig reagent (R)-(−)-5, and iodide (S)-(−)-6. (+)-Dpd (2) is a degradation product of bone collagen and has been found to be a useful marker for diagnosis of osteoporosis and other metabolic bone diseases.
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Synthesis of isotopically labeled (+)-Deoxypyridinoline
Journal of Labelled Compounds and Radiopharmaceuticals, 2000Co-Authors: Maciej Adamczyk, Donald D. Johnson, Rajarathnam E. Reddy, Sushil D. RegeAbstract:An efficient synthesis of isotopically labeled (+)-Deoxypyridinoline (3) was achieved via quaternization of (S,S)(−)-4 with (S)-(−)-iodide (5) and subsequent hydrolysis. The required (S)-(−)-iodide (5) was prepared from a commercially available (S)-5-(tert-butoxy)-4-[tert-butoxycarbonyl)amino]-5-oxopentanoic acid (6) in seven steps and good overall yield. Copyright © 2000 John Wiley & Sons, Ltd.
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Transformation of Vitamin B6 to (+)-Deoxypyridinoline, a useful Biochemical Marker for Diagnosis of Bone Diseases
Tetrahedron, 2000Co-Authors: Maciej Adamczyk, Srinivasa Rao Akireddy, Rajarathnam E. ReddyAbstract:Abstract A versatile chiral synthesis of the cross-link (+)-Deoxypyridinoline (Dpd, 2) was achieved starting from vitamin B6 (7). The key steps in the synthesis of (+)-2 are transformation of B6 (7) to the chloride (3d) and construction of three α-amino acid chains by utilizing (R)-(−)-Schollkopf's reagent (4), Wittig reagent (R)-(−)-5, and iodide (S)-(−)-6. (+)-Dpd (2) is a degradation product of bone collagen and has been found to be a useful marker for diagnosis of osteoporosis and other metabolic bone diseases.
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an efficient one pot synthesis of Deoxypyridinoline
Tetrahedron Letters, 1999Co-Authors: Maciej Adamczyk, Donald D. Johnson, Rajarathnam E. ReddyAbstract:Abstract An efficient one-pot synthesis of (+)-Deoxypyridinoline (Dpd, 1 ), the cross-link of bone collagen, was achieved from tert -butyl-( S )-(−)-[(2- tert -butoxycarbonyl)amino]-6-aminohexanoate ( 2 ) and tert -butyl-( S )-(−)-6-bromo-2-[bis( tert -butoxycarbonyl)amino]-5-oxohexanoate ( 3 ) in 42% yield.
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versatile synthesis of Deoxypyridinoline a biochemical marker for diagnosis of osteoporosis
Tetrahedron-asymmetry, 1999Co-Authors: Maciej Adamczyk, Srinivasa Rao Akireddy, Rajarathnam E. ReddyAbstract:Abstract A versatile chiral synthesis of the bone collagen cross-link, (+)-Deoxypyridinoline (Dpd, 1 ) was described starting from a 3-hydroxypyridine derivative ( 2 ) via sequential introduction of three amino acid chains followed by hydrolysis. The key synthon 2 , was prepared from vitamin B 6 ( 6 ).
Markus J Seibel - One of the best experts on this subject based on the ideXlab platform.
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urinary free Deoxypyridinoline by chemiluminescence immunoassay analytical and clinical evaluation
Clinical Chemistry, 1998Co-Authors: Thomas G. Rosano, R Peaston, Henry G. Bone, Henning W. Woitge, Roger M. Francis, Markus J SeibelAbstract:We evaluated an automated chemiluminescence immunoassay (CLIA) developed for the measurement of urinary free Deoxypyridinoline (DPD). The new DPD method by CLIA is based on the competition of DPD with particle-bound pyridinoline for a limited amount of monoclonal mouse anti-DPD antibody. Total imprecision (CV) was 3.2–9.0% at 30–270 nmol/L. Regression analysis of urinary DPD concentration (second morning-void) measured by CLIA ( y ) and enzyme immunoassay (EIA) for adult volunteers (n = 449) with and without bone disease revealed a best fit equation of: y = 1.08 ± 0.03 x − 1.15 ± 0.98 nmol/L ( r = 0.964, S y‖x = 14 nmol/L). CLIA and EIA methods were correlated with HPLC measurement of urinary free DPD ( r = 0.846 and 0.871, respectively). For healthy adults, the creatinine-normalized excretion of DPD (mean ± SD) measured by CLIA for 61 men (4.1 ± 1.2 μmol DPD/mol creatinine) and 76 premenopausal women (5.3 ± 1.8 μmol DPD/mol creatinine) did not differ significantly ( P >0.05) from DPD excretion measured by EIA, and both immunoassays showed a significant gender difference ( P <0.001) in reference intervals. In a clinical trial, DPD excretion (μmol DPD/mol creatinine) measured by CLIA differed substantially from the reference population for 54 untreated pagetic (12.7 ± 8.0 SD), 255 untreated osteoporotic (7.5 ± 4.1), 21 osteomalacic (12.4 ± 8.5), 17 primary hyperparathyroid (9.4 ± 4.4), and 14 secondary hyperparathyroid (9.2 ± 5.1) patients. Clinical sensitivities of the CLIA and EIA methods range from 38% to 80% in bone disorders and limit the use of the DPD measurement in disease detection. DPD excretion after pamidronate treatment in a subgroup of the pagetic patients fell dramatically as assessed by CLIA or EIA. We conclude that the automated CLIA method for DPD is a convenient and reliable method that may aid in the evaluation and management of bone disease and is applicable to high volume testing in the routine clinical laboratory.
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Urinary free Deoxypyridinoline by chemiluminescence immunoassay: analytical and clinical evaluation
Clinical chemistry, 1998Co-Authors: Thomas G. Rosano, R Peaston, Henry G. Bone, Henning W. Woitge, Roger M. Francis, Markus J SeibelAbstract:We evaluated an automated chemiluminescence immunoassay (CLIA) developed for the measurement of urinary free Deoxypyridinoline (DPD). The new DPD method by CLIA is based on the competition of DPD with particle-bound pyridinoline for a limited amount of monoclonal mouse anti-DPD antibody. Total imprecision (CV) was 3.2–9.0% at 30–270 nmol/L. Regression analysis of urinary DPD concentration (second morning-void) measured by CLIA ( y ) and enzyme immunoassay (EIA) for adult volunteers (n = 449) with and without bone disease revealed a best fit equation of: y = 1.08 ± 0.03 x − 1.15 ± 0.98 nmol/L ( r = 0.964, S y‖x = 14 nmol/L). CLIA and EIA methods were correlated with HPLC measurement of urinary free DPD ( r = 0.846 and 0.871, respectively). For healthy adults, the creatinine-normalized excretion of DPD (mean ± SD) measured by CLIA for 61 men (4.1 ± 1.2 μmol DPD/mol creatinine) and 76 premenopausal women (5.3 ± 1.8 μmol DPD/mol creatinine) did not differ significantly ( P >0.05) from DPD excretion measured by EIA, and both immunoassays showed a significant gender difference ( P
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urinary pyridinium crosslinks of collagen specific markers of bone resorption in metabolic bone disease
Trends in Endocrinology and Metabolism, 1992Co-Authors: Markus J Seibel, Simon P. Robins, John P BilezikianAbstract:The hydroxypyridinium compounds pyridinoline and Deoxypyridinoline are specific constituents of mature skeletal collagens. They are released into the circulation and excreted in the urine. Their measurement in urine is a sensitive index of the extent of ongoing bone resorption. Currently, quantification of collagen crosslinks in urine is achieved by chromatographic techniques, but more convenient immunoassays will make these measurements more widely available in the near future. Clinical applications of hydroxypyridinium markers include numerous metabolic bone disorders such as osteoporosis, primary hyperparathyroidism, Paget's disease of bone, and metastatic bone disease. Urinary pyridinium crosslinks of collagen also show great promise as markers of therapeutic efficacy in bone disorders associated with accelerated bone resorption.
G Neil Kent - One of the best experts on this subject based on the ideXlab platform.
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Age-related changes in collagen, pyridinoline, and Deoxypyridinoline in normal human thoracic intervertebral discs.
The journals of gerontology. Series A Biological sciences and medical sciences, 2003Co-Authors: Celia I Tan, G Neil Kent, Andrew G Randall, Stephen J Edmondston, Kevin P SingerAbstract:Human thoracic discs were analyzed for collagen and collagen cross-links to determine the distribution due to segmental, age, and gender influences. Thoracic discs from 26 cadaveric spines (1 to 90 years old) were graded macroscopically, then separated into anular and nuclear samples. Only grade I (i.e., normal) disc samples were selected (n=209). Pyridinoline and Deoxypyridinoline cross-links were initially separated by column chromatography and analyzed by reverse-phase high-pressure liquid chromatography. The collagen content was lower and the extent of pyridinoline and Deoxypyridinoline were significantly higher in the nucleus compared with the anulus (p
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Age-Related Changes in Collagen, Pyridinoline, and Deoxypyridinoline in Normal Human Thoracic Intervertebral Discs
Journals of Gerontology Series A-biological Sciences and Medical Sciences, 2003Co-Authors: Celia I Tan, G Neil Kent, Andrew G Randall, Stephen J Edmondston, Kevin P SingerAbstract:Human thoracic discs were analyzed for collagen and collagen cross-links to determine the distribution due to segmental, age, and gender influences. Thoracic discs from 26 cadaveric spines (1 to 90 years old) were graded macroscopically, then separated into anular and nuclear samples. Only grade I (i.e., normal) disc samples were selected (n ¼ 209). Pyridinoline and Deoxypyridinoline cross-links were initially separated by column chromatography and analyzed by reverse-phase high-pressure liquid chromatography. The collagen content was lower and the extent of pyridinoline and Deoxypyridinoline were significantly higher in the nucleus compared with the anulus (p , .001). The collagen content and extent of pyridinoline were significantly lower with increasing age in the anulus and nucleus (p , .001). Young male discs had a significantly higher extent of pyridinoline compared with females (p , .001). Age, gender, and disc region differences were found to have a significant influence on the biochemical composition of the normal disc extracellular matrix.
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Standardization of marker assays--pyridinoline/Deoxypyridinoline.
Scandinavian journal of clinical and laboratory investigation. Supplementum, 1997Co-Authors: G Neil KentAbstract:The hydroxypyridinium collagen crosslinks pyridinoline and Deoxypyridinoline (Dpd) are released during the degradation of some mature collagens. Assays for the peptide forms of these crosslinks in blood and urine and for the free and total crosslinks in urine have been developed. Currently there is no internationally accepted reference standard for use in any of these assays. Recently the criteria and strategy for the preparation of a Dpd standard have been described. Using the UV molar absorptivity of 5160 L/mol/cm at 294 nm in 0.1 mol/L HCl and purity checked by NMR spectroscopy, mass spectrometry and elemental analysis sufficient quantities of this reference standard will have to be prepared. Protection from photolysis is essential to ensure stability of the reference preparation. This reference preparation will be suitable for calibration of immunoassays for free Dpd and for HPLC assays of free and total Dpd. The assays for peptide forms of the crosslinks have used standards prepared either by enzymatically digesting collagen or synthesis of oligopeptides. The problem of standardization of some of these peptide assays may be resolved if a reference preparation of digested bone collagen can be produced and appropriately characterised.
Kevin P Singer - One of the best experts on this subject based on the ideXlab platform.
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Age-related changes in collagen, pyridinoline, and Deoxypyridinoline in normal human thoracic intervertebral discs.
The journals of gerontology. Series A Biological sciences and medical sciences, 2003Co-Authors: Celia I Tan, G Neil Kent, Andrew G Randall, Stephen J Edmondston, Kevin P SingerAbstract:Human thoracic discs were analyzed for collagen and collagen cross-links to determine the distribution due to segmental, age, and gender influences. Thoracic discs from 26 cadaveric spines (1 to 90 years old) were graded macroscopically, then separated into anular and nuclear samples. Only grade I (i.e., normal) disc samples were selected (n=209). Pyridinoline and Deoxypyridinoline cross-links were initially separated by column chromatography and analyzed by reverse-phase high-pressure liquid chromatography. The collagen content was lower and the extent of pyridinoline and Deoxypyridinoline were significantly higher in the nucleus compared with the anulus (p
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Age-Related Changes in Collagen, Pyridinoline, and Deoxypyridinoline in Normal Human Thoracic Intervertebral Discs
Journals of Gerontology Series A-biological Sciences and Medical Sciences, 2003Co-Authors: Celia I Tan, G Neil Kent, Andrew G Randall, Stephen J Edmondston, Kevin P SingerAbstract:Human thoracic discs were analyzed for collagen and collagen cross-links to determine the distribution due to segmental, age, and gender influences. Thoracic discs from 26 cadaveric spines (1 to 90 years old) were graded macroscopically, then separated into anular and nuclear samples. Only grade I (i.e., normal) disc samples were selected (n ¼ 209). Pyridinoline and Deoxypyridinoline cross-links were initially separated by column chromatography and analyzed by reverse-phase high-pressure liquid chromatography. The collagen content was lower and the extent of pyridinoline and Deoxypyridinoline were significantly higher in the nucleus compared with the anulus (p , .001). The collagen content and extent of pyridinoline were significantly lower with increasing age in the anulus and nucleus (p , .001). Young male discs had a significantly higher extent of pyridinoline compared with females (p , .001). Age, gender, and disc region differences were found to have a significant influence on the biochemical composition of the normal disc extracellular matrix.