Riddellic acid

CXXXII a Isoseneciphyllic acid CXXXII b Seneciphyllic acid CXXXII c Riddellic acid CXXXII d Spartiodinecic acid... 

If hydrogenation of riddelliine was carried out over platinum oxide, four mole equivalents of hydrogen were rapidly absorbed but the octahydro-riddelliine was not isolated. Alkaline hydrolysis of the crude reaction product yielded retronecanol and an acid which resisted purification. The additional two moles of hydrogen must have reacted with the acid portion of the molecule, a fact which agrees with the hydrogenation of riddellic acid itself. 

Commercial processes Commercial electroless nickel plating stems from an accidental discovery by Brenner and Riddell made in 1944 during the electroplating of a tube, with sodium hypophosphite added to the solution to reduce anodic oxidation of other bath constituents. This led to a process available under licence from the National Bureau of Standards in the USA. Their solutions contain a nickel salt, sodium hypophosphite, a buffer and sometimes accelerators, inhibitors to limit random deposition and brighteners. The solutions are used as acid baths (pH 4-6) or, less commonly, as alkaline baths (pH 8-10). Some compositions and operating conditions are given in Table 13.17 . 

Caulfield, W. J. and Riddell, W. H. 1936. Some factors influencing the acidity of freshly drawn cows milk. J. Dairy Sci. 19, 235-242. 

Riddellic l,2-Dihydroxy-3-methylhepta-3,5-diene-2,5-dicarboxylic acid Riddelliine 102-103 - 2.6°... 

Figure 5-4. Dose-response curves of two normal human subjects to intravenous infusion of histamine. H is the calculated secretory maximum. (From Adams HM, Card Wl, Riddell MJ, et al. Dose-response curves for effect of histamine on acid secretion in man. Br I Pharmacol 9 329-334, 1954.)...

Adams HM, Card WI, Riddell MJ, et al. Dose-response curves for effect of histamine on acid secretion in man. Br J Pharmacol 9 329-334, 1954. 

Riddell, D.O., Bartley, E.E. and A.D. Dayton, 1981. Effect of nicotinic acid on microbial protein synthesis /i v/tro and on dairy cattle growth and milk production. J. Dairy Sci. 64,782-791. 

---