PMID: 8207670Mar 1, 1994Paper

Metal complexes of anhydrotetracycline. 1. A spectrometric study of the Cu(II) and Ni(II) complexes

Journal of Pharmaceutical Sciences
J M de SiqueiraH Beraldo


Anhydrotetracycline (AHTC), one of the major toxic decomposition products of the antibiotic tetracycline, contains several potential binding sites to metal ions. The acidity constants of the ligand were calculated in aqueous medium (I = 0.1 M) at 25 and 37 degrees C. We found pKa1 = 3.23 +/- 0.08, pKa2 = 5.94 +/- 0.09, and pKa3 = 8.48 +/- 0.02 at 25 degrees C and pKa1 = 3.12 +/- 0.09, pKa2 = 5.86 +/- 0.03, and pKa3 = 8.38 +/- 0.04 at 37 degrees C. The coordination of AHTC to Cu(II) and Ni(II) ions was studied in the solid state as well as in buffered aqueous solution at pH 10.0. At this pH, the formation of the two CuL2 and CuL species was indicated (log beta 1 = 8.41 +/- 0.04 and log beta 2 = 12.55 +/- 0.05), but only the formation of the NiL complex (log beta = 5.74 +/- 0.04) was identified. Spectroscopic data confirm the previous assignment of the C11 and C12 oxygens as the coordination sites, yielding six-membered ring chelates and excluding complexation through any of the potential binding positions on ring A.


❮ Previous
Next ❯


Dec 22, 1999·Journal of Inorganic Biochemistry·F C de PaulaE C Pereira-Maia
Aug 2, 2011·Biological & Pharmaceutical Bulletin·Martha Ines BurgosSergio Alberto Dassie
May 9, 2014·Journal of Fluorescence·Elmer-Rico E MojicaFrank V Bright
Sep 2, 1998·Journal of Pharmaceutical Sciences·W B De AlmeidaM C Zerner
Nov 29, 2011·Physical Chemistry Chemical Physics : PCCP·Benedetta CarlottiFausto Elisei
Jan 6, 1999·Journal of Pharmaceutical Sciences·H A DuarteA M Simas
Mar 31, 1998·Journal of Pharmaceutical Sciences·H F Dos SantosM C Zerner

❮ Previous
Next ❯

Related Concepts

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.


Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.


Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.