CovX Research

San Diego, CA, United States

CovX Research

San Diego, CA, United States
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Magano J.,Pfizer | Farrand D.,Pfizer | Haase J.P.,Pfizer | Lovdahl M.,Pfizer | And 8 more authors.
Tetrahedron Letters | Year: 2012

An optimized and scalable synthesis of a novel analytical reagent for the determination of the number of active sites available for conjugation on a catalytic aldolase monoclonal antibody (mAb) is described. The original conditions suffered from lack of reproducibility, incomplete reactions, and required several chromatographies and lyophilizations that afforded material of low purity. A redesigned route and optimized protocols have been developed that eliminate the use of toxic and unsafe reagents such as HMPA and HATU. In addition, the number of chromatographies has been reduced to only one and time-consuming and energy-intensive lyophilizations are no longer required. The overall yield has been considerably improved from the original 4% to 20% after telescoping the last two steps of the synthesis and this new approach allowed for the preparation of material with higher chemical purity (≥99% vs the initial 90%) to meet specifications. © 2012 Elsevier Ltd. All rights reserved.

Magano J.,Pfizer | Bock B.,Pfizer | Brennan J.,Pfizer | Farrand D.,Pfizer | And 9 more authors.
Organic Process Research and Development | Year: 2014

An optimized and scalable process to manufacture peptide-linker conjugate 1 is reported that avoids the chromatographic purification and lyophilization that are typically required for the isolation of this type of compound. An operationally simple protocol has been developed that couples the peptide to the linker in DMF followed by precipitation with MeCN. A scalable synthesis of the linker is also described which features the N-acylation of 2-azetidinone promoted by 1- propanephosphonic acid anhydride (T3P). The number of operations during the second step of the synthesis (nitrobenzene reduction to aniline) has been simplified by telescoping the aniline into the next step (reaction with diglycolic anhydride to form an acid), thus avoiding an additional isolation. Finally, two efficient activation methods for the acid have been developed by means of the corresponding pentafluorophenyl (PFP) and p-nitrophenyl (PNP) esters. © 2013 American Chemical Society.

Donahoo W.T.,University of Colorado at Denver | Stob N.R.,University of Colorado at Denver | Ammon S.,University of Colorado at Denver | Levin N.,CovX Research | Eckel R.H.,University of Colorado at Denver
Metabolism: Clinical and Experimental | Year: 2011

The ability of leptin to preserve lean tissue during weight loss may be in part due to differences in nutrient partitioning. Because lipoprotein lipase (LPL) plays a key role in partitioning lipid nutrients, this study was conducted to test the hypothesis that leptin would modify the tissue-specific regulation of LPL and result in increased lipid oxidation and decreased storage. The effects of daily intraperitoneal leptin injections (2 mg/kg body weight) over 2 weeks on LPL activity and postprandial lipid metabolism were tested in both wild-type (WT), leptin-deficient ob/ob obese mice and mice pair fed to the leptin-treated mice. On the experimental day, mice were given food by gavage, blood was drawn periodically, and adipose tissue and skeletal muscle were harvested for measurements of LPL activity at 240 minutes. After 2 weeks of leptin administration, skeletal muscle LPL (SMLPL) activity was increased in leptin-treated compared with pair-fed (P = .012) and WT (P = .002) mice. There was no effect of leptin or pair feeding on postprandial adipose tissue LPL activity. In ob/ob mice, leptin treatment normalized the decrease in postprandial free fatty acid concentration (P = .066). Leptin had no effect on either the area under the triglyceride (TG) excursion or the integrated area under the TG excursion in WT mice. In ob/ob mice, however, the TG excursion was lower in the leptin-treated than the pair-fed mice by area under the TG excursion (P = .012) and was lower than in the WT mice by integrated area under the TG excursion (P = .027). As expected, 2 weeks of leptin treatment decreased body weight in both the WT and ob/ob mice (-2.6% and -10.4%, respectively). Leptin treatment increased SMLPL, an effect that may have contributed to the leptin-induced weight loss. The leptin-induced decreased postprandial TG excursion in ob/ob mice suggests that leptin acts to augment clearance of postprandial TG-rich lipoprotein lipid and that this increase may in part be secondary to the increased activity of SMLPL. The trend for decreased postprandial free fatty acid may indicate that leptin decreases adipose tissue lipid stores without increasing lipolysis. © 2011 Elsevier Inc. All rights reserved.

Magano J.,Pfizer | Conway B.G.,Pfizer | Farrand D.,Pfizer | Lovdahl M.,Pfizer | And 5 more authors.
Synthesis (Germany) | Year: 2014

An efficient, scalable, and cost-effective synthesis of a linker employed in a bioconjugation process with a peptide and a monoclonal antibody is presented. Several routes were investigated that resulted in the identification of a short synthesis to a key acid intermediate from inexpensive and readily available starting materials. The final coupling of this acid with an aniline to afford the desired linker has been optimized to produce multi-gram quantities of material for clinical studies. The very limited purifications needed for both intermediates and final product make this route amenable to scale. © Georg Thieme Verlag Stuttgart New York.

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