Chlorotetracycline
[CAS# 57-62-5]

Identification

• Classification: API >> Antibiotics >> Tetracycline
• Name: Chlorotetracycline
• Synonyms: 7-Chloro-4-(dimethylamino)-1,4,4a,5,5a,6,11,12a-octahydro-3,6,10,12,12a-pentahydroxy-6-methyl-1,11-dioxo-2-naphthacenecarboxamide
• Molecular Formula: C₂₂H₂₃ClN₂O₈
• Molecular Weight: 478.88
• CAS Registry Number: 57-62-5
• EC Number: 200-341-7
• SMILES: C[C@@]1([C@H]2C[C@H]3[C@@H](C(=O)C(=C([C@]3(C(=O)C2=C(C4=C(C=CC(=C41)Cl)O)O)O)O)C(=O)N)N(C)C)O

Properties

• Density: 1.7±0.1 g/cm³, Calc.^*
• Index of Refraction: 1.745, Calc.^*
• Boiling Point: 821.1±65.0 °C (760 mmHg), Calc.^*
• Flash Point: 450.4±34.3 °C, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS07 Warning
• Risk Statements: H302
• Safety Statements: P264-P270-P301+P317-P330-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302

Discovery and Applications

Chlorotetracycline is a chemical compound classified as a tetracycline antibiotic. It is a derivative of tetracycline, a widely used class of antibiotics that was first discovered in the 1940s. Chlorotetracycline is characterized by the presence of a chlorine atom at the C-7 position of the tetracycline core structure. This modification distinguishes it from other tetracyclines and influences its spectrum of activity, as well as its pharmacokinetic properties.

The discovery of chlorotetracycline dates back to the early 1950s, when it was first isolated from cultures of the bacterium *Streptomyces aureofaciens*. This organism was identified as a source of various bioactive compounds, including tetracyclines, which showed broad-spectrum antibacterial activity. Chlorotetracycline, along with other tetracyclines, quickly became an important therapeutic agent due to its efficacy in treating a wide range of bacterial infections.

Chlorotetracycline functions as a protein synthesis inhibitor by binding to the bacterial ribosome, thereby preventing the addition of amino acids to the growing polypeptide chain. This mechanism of action makes it effective against a variety of Gram-positive and Gram-negative bacteria, as well as some protozoa. Its antibacterial activity is similar to other tetracyclines, and it has been used to treat infections such as pneumonia, urinary tract infections, and respiratory tract infections.

In addition to its antibacterial properties, chlorotetracycline has also been studied for its potential use in veterinary medicine. It has been used in the treatment of livestock and poultry for various bacterial infections, contributing to its widespread application in agriculture. In the early years of its use, chlorotetracycline was also employed as a growth promoter in animals, though such practices have become increasingly controversial due to concerns about antibiotic resistance and its impact on human health.

The use of chlorotetracycline in clinical settings has declined with the introduction of more advanced antibiotics that are often more effective and less prone to resistance. However, chlorotetracycline remains a valuable reference compound in the study of antibiotic resistance and continues to serve as a basis for the development of new tetracycline derivatives with improved properties.

Chlorotetracycline has also found application in laboratory research, particularly in studies related to the inhibition of protein synthesis. It is often used in microbiological experiments to control bacterial growth and to investigate the mechanisms of antibiotic action. In addition, it has been employed in the preparation of conjugates for molecular imaging and drug delivery, further expanding its utility beyond its initial role as an antibiotic.

Despite the availability of newer antibiotics with broader spectra and fewer side effects, chlorotetracycline remains a key compound in the history of antibiotics and continues to be used in specific contexts where its properties are beneficial.

References

1969. pH-Partition Behavior of Tetracyclines. Journal of Pharmaceutical Sciences, 58(10).
DOI: 10.1002/jps.2600581003

1979. Use of chlorotetracycline fluorescence to demonstrate Ca2+-induced release of Ca2+ from the sarcoplasmic reticulum of skinned cardiac cells. Nature, 281(5727).
DOI: 10.1038/281146a0

2024. Recent advances in the removal of emerging pollutant tetracycline using green nanomaterials: An eco-friendly mitigation approach. International Journal of Environmental Science and Technology.
DOI: 10.1007/s13762-024-06163-w