Steroid-copper complexes

To evaluate the time-course of analgesia associated with a non-steroidal anti-inflammatory agent and its copper complex, salicylic acid and its complex were compared in the polyarthritis pain model following oral administration in 5 % gum arabic. Data presented in Figure 6.4 show that analgesic activity increased in a dose-related manner and that Cu(II))(salicylate)2 was 7- to... 

Copper complex modulation of steroid hydroxylations have also been reported [690]. A single dose of Cu(II)sulphate injected into rats caused a 2-to 3-fold increase in adrenal copper, a significant (P < 0.05) increase in mitochondrial P-450-dependent steroid 11-jS-hydroxylase activity, and an 85% increase in concentration of P-450 as well as a 3-fold increase in fi-aminolevuli-nate synthetase, which suggests a positive feedback stimulation of P-450 synthesis. Chronic treatment with Cu(II)sulphate for 7 days caused a decrease in 11-jS-hydroxylase activity (P<0.05) and a decrease in plasma corticosterone concentration (P<0.05) while there was a concomitant increase in cholesterol side-chain cleavage, suggesting the metabolism of cholesterol by some other P-450 following maximal corticosterone synthesis. A positive feedback for 6-aminolevulinate synthesis was also evidenced by an increase in synthetase activity. 

Stereoselective allylic alkylations have been carried out with the aid of palladium catalysts. The 17-(Z)-ethylidene groups of steroids (obtained from the ketones by Wittig olefination) form n-allyl palladium complexes in the presence of copper(n) salts (B.M. Trost, 1974, 1976). Their alkylation with dimethyl malonate anions in the presence of 1,2-ethane-diylbis[diphenylphosphine] (— diphos) gives a reaction exclusively at the side chain and only the (20S) products. If one starts with the endocyclic 16,17 double bond and replaces an (S)-20-acetoxy group by using tetrakis(triphenylphospbine)palladium,the substitution occurs with complete retention of configuration, resulting from two complete inversions (B.M. Trost, 1976). 

These experiments were undertaken in a similar manner to those described by Brady and Sanders for measuring relative binding affinities of metals with steroid derivatives by ESI-MS. Titrations with zinc and copper solutions were carried out on patellamides C and A by sequential addition of 0.25 equivalents of the metal solutions to the peptides (cone. 0.02 mg/mL in MeOH). These titrations were monitored by measuring the formation of the metal species as well as the loss of the uncomplexed peptides, using both the full spectrum and the selected ion mode of the instrument in parallel, as the ionisation efficiency of these species were very different. Once fully complexed zinc species were obtained for each peptide, copper solution was then titrated into these at a rate of 0.25 equivalents to again observe the competition effects. 

An EPR-signal of the biuret-type is observed. Therefore in blood serum these complexes are only existing in very low concentrations. Many acetate-like copper chelators like salicylate are used as non-steroidal antiinflammatory drugs (for a review see They are potent inhibitors of lipid peroxidation In biological tissues, these... 

Organo-SOMO catalysis was also applied to polyene cyclization. In 2010, MacMillan reported an enantioselective cyclization reaction of substrates 41 for accessing steroidal and terpenoidal frameworks. They used imidazolidinone 40 instead of catalyst 23, with the aid of copper(ll) triflate as the oxidant. The polyene cyclization took place smoothly, giving polycyclic systems 42 and even more complex compounds 43 or 44 in good yields and with high enantioselectivity and exclusive diastereoselectivity (Scheme 36.12) [18]. 

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