Synthetic Routes to Some Isotopically Labeled Intermediates for Diterpenoid Biosynthesis

1989 ◽  
Vol 42 (4) ◽  
pp. 561 ◽  
Author(s):  
RM Dawson ◽  
IM Godfrey ◽  
RW Hogg ◽  
JR Knox
Keyword(s):  
Specific Activity ◽  
High Specific Activity ◽  
Allylic Alcohol ◽  
Isotopic Labelling ◽  
Efficient Procedure ◽  
Ene Reaction ◽  
Vinyl Bromide ◽  
Exocyclic Methylene ◽  
Synthetic Routes ◽  
Methylene Group

The exo-15-hydrogen of ent-kaurene can be exchanged through a reversible ene reaction in a convenient and efficient procedure which has the potential for giving high specific activity 3H-labelling. Copalol, the (Z)-double bond stereoisomer, and the allylic alcohol isomers ent-manool and ent-epimanool have been obtained through divergent synthetic pathways involving a 15,16-bisnor ketone intermediate. These pathways have also allowed the four compounds to be obtained with 14C-labelling. A method, involving a Wittig reaction to form a vinyl bromide intermediate, has been developed for obtaining copalol, as the trityl ether derivative, with stereospecific isotopic labelling of one or the other of the hydrogens of the exocyclic methylene group.

Effects of Heparin Oligosaccharides with High Affinity for Antithrombin III in Experimental Venous Thrombosis

1982 ◽  
Vol 47 (03) ◽  
pp. 244-248 ◽  
Author(s):  
D P Thomas ◽  
Rosemary E Merton ◽  
T W Barrowcliffe ◽  
L Thunberg ◽  
U Lindahl
Keyword(s):  
Antithrombin Iii ◽  
Specific Activity ◽  
High Specific Activity ◽  
Factor Xa ◽  
Blood Levels ◽  
Thrombin Time ◽  
High Affinity ◽  
Very High

SummaryThe in vitro and in vivo characteristics of two oligosaccharide heparin fragments have been compared to those of unfractionated mucosal heparin. A decasaccharide fragment had essentially no activity by APTT or calcium thrombin time assays in vitro, but possessed very high specific activity by anti-Factor Xa assays. When injected into rabbits at doses of up to 80 ¼g/kg, this fragment was relatively ineffective in impairing stasis thrombosis despite producing high blood levels by anti-Xa assays. A 16-18 monosaccharide fragment had even higher specific activity (almost 2000 iu/mg) by chromogenic substrate anti-Xa assay, with minimal activity by APTT. When injected in vivo, this fragment gave low blood levels by APTT, very high anti-Xa levels, and was more effective in preventing thrombosis than the decasaccharide fragment. However, in comparison with unfractionated heparin, the 16-18 monosaccharide fragment was only partially effective in preventing thrombosis, despite producing much higher blood levels by anti-Xa assays.It is concluded that the high-affinity binding of a heparin fragment to antithrombin III does not by itself impair venous thrombogenesis, and that the anti-Factor Xa activity of heparin is only a partial expression of its therapeutic potential.

Autoprothrombin C Activity from Prothrombin with Snake Venom or Trypsin

1962 ◽  
Vol 08 (03) ◽  
pp. 425-433 ◽  
Author(s):  
Ewa Marciniak ◽  
Edmond R Cole ◽  
Walter H Seegers
Keyword(s):  
Snake Venom ◽  
Thrombolytic Agent ◽  
Sodium Citrate ◽  
Specific Activity ◽  
High Specific Activity ◽  
Citrate Solution ◽  
Clotting Factors ◽  
Activation Products ◽  
Russell’S Viper ◽  
Autoprothrombin C

SummarySuitable conditions were found for the generation of autoprothrombin C from purified prothrombin with the use of Russell’s viper venom or trypsin. DEAE chromatographed prothrombin is structurally altered and has never been found to yield autoprothrombin C and also did not yield it when Russell’s viper venom or trypsin were used. Autoprothrombin C is derived from prothrombin with tissue extract thromboplastin, but not in large amounts with the intrinsic clotting factors. With the latter thrombin and autoprothrombin III are the chief activation products. Autoprothrombin III concentrates were prepared from serum and upon activation with 25% sodium citrate solution or with Russell’s viper venom large amounts of autoprothrombin C were obtained, and this was of high specific activity. Theoretically trypsin is not a thrombolytic agent, but on the contrary should lead to intravascular clotting.

In-Canal Assay of High Specific Activity 60Co at the Advanced Test Reactor

2021 ◽  
pp. 1-7
Author(s):  
Michael A. Reichenberger ◽  
Jagoda M. Urban-Klaehn ◽  
Jason V. Brookman ◽  
Joshua L. Peterson-Droogh ◽  
Jorge Navarro ◽  
...  
Keyword(s):  
Specific Activity ◽  
High Specific Activity ◽  
Test Reactor

scholarly journals High Specific Activity Labeling of Insulin with 131I

1964 ◽  
Vol 239 (11) ◽  
pp. 3743-3748 ◽  
Author(s):  
Joseph L. Izzo ◽  
William F. Bale ◽  
Mary Jane Izzo ◽  
Angela Roncone
Keyword(s):  
Specific Activity ◽  
High Specific Activity

[125I]Iberiotoxin-D19Y/Y36F, the First Selective, High Specific Activity Radioligand for High-Conductance Calcium-Activated Potassium Channels

Biochemistry ◽  
1997 ◽  
Vol 36 (7) ◽  
pp. 1943-1952 ◽  
Author(s):  
Alexandra Koschak ◽  
Robert O. Koch ◽  
Jessica Liu ◽  
Gregory J. Kaczorowski ◽  
Peter H. Reinhart ◽  
...  
Keyword(s):  
Potassium Channels ◽  
Specific Activity ◽  
High Specific Activity ◽  
Calcium Activated Potassium Channels ◽  
High Conductance

Production of [3H]patulin of high specific activity

1979 ◽  
Vol 17 (1) ◽  
pp. 55-59
Author(s):  
T.J. Gillespie ◽  
R.L. Price
Keyword(s):  
Specific Activity ◽  
High Specific Activity
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