Spectrophotometric determination of acidity constants of 4-dedimethylamino sancycline (Col-3), a new antitumor drug.
A spectrophotometric technique was used to determine the acidity constants of 4-dedimethylamino sancycline (Col-3), a new antitumor drug. The apparent pKa values of Col-3 in 0.5% methanol aqueous media at approximately 25 degrees C with a constant ionic strength of 0.2 were calculated manually and graphically to be 5.64 +/- 0.17 (pKa1) and 8.35 +/- 0.07 (pKa2). In addition, the computer program SQUAD was used to confirm Col-3 pKa values. The pKa values obtained by SQUAD were pKa1 5.63 +/- 0.14 and pKa2 8.39 +/- 0.04. These results are in agreement with the tetracycline-like structure of Col-3.
Pinsuwan
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S
Department of Pharmaceutical Technology, Prince of Songkla University, Songkhla, Thailand.
Alvarez-Núñez
F A
FA
Tabibi
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SE
Yalkowsky
S H
SH
D000970:Antineoplastic Agents / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D013053:Spectrophotometry; D013752:Tetracycline / Q000737:chemistry*; D013754:Tetracyclines
D000970:Antineoplastic Agents; D013754:Tetracyclines; C117155:tetracycline CMT-3; D013752:Tetracycline