Tetracycline 6-demethyl

The 7-chloro-derivative, the first of the group to be isolated (1948) is known as chlortetracy-cline. The 5-hydroxy-derivative is oxytetracy-dine. More recently introduced tetracyclines are 6-demethyl-7-chlorotetracycline and 5-hydroxy-6-deoxy-6-methyienetetracycline. 

Fig. 1. Tetracycline (1) and its derivatives chlortetracycline (7-chlorotetracycline) (2) oxytetracycline (5-hydroxytetracycline) (3), demeclocycline (6-demethyl-7-chlorotetracycline) (4) methacycline (6-demethyl-6-deoxy-5-hydroxy-6-methylenetetracycline) (5) doxycycline (6a-deoxy-5-hydroxytetracycline) (6) and minocycline (6-demethy1-6-deoxy-7-dimethy1 amino tetracycline) (7). Substituents at positions not specifically...

The 6- uoro isomers, 6-deoxy-6-demethyl-6a- uorotetracycline [24333-20-8] C2 H2 FN20y, and 6-deoxy-6-demethyl-6P- uorotetracycline [24333-21-9] C2 H2 FN202, have been prepared and showed relatively high in vitro and in vivo biological activities compared to the parent tetracyclines. 

Fig. 5.8 Structures of two tetracycline analogues, which are members of the new glycylcycline group of antibiotics A, yV,A -dimethylglycylamido-6-demethyl-6-deoxytetracycline B, N,N-dimethylglycylamidominocycline.

Interesting photolyses have been reported in the tetracycline series.112 Irradiation of the hydrochloride of 6-demethyl-6-deoxytetracycline-7-diazonium sulfate in acetic acid gives 6-demethyl-6-deoxytetracycline (A). The reaction also gives 7-bromo-, 7-fluoro, and 7-acetoxy-6-de-... 

For almost half a century, tetracycline (68) has been well-known as a major antibiotic from the viewpoint of its unique structural features as well as antibacterial activities 24). The total synthesis of tetracycline families was initiated by Woodward s 6-demethyl-6-deoxytetracycline synthesis in 1962 (25), followed by Muxfeldt s terramycin synthesis in 1968 (26), and culminated by Stork s 12a-deoxytetracycline synthesis in 1996 (27). However, all these syntheses have been accomplished only in racemic forms. The total synthesis of... 

TETRACOMPREN see TBX250 TETRACYANONICKELATE(2-) DIPOTASSIUM, HYDRATE see TBW250 TETRACYCLINE CHLORIDE see TBX250 TETRACYCUNE, 7-CHLORO-6-DEMETHYL- see MIJ500... 

Deoxy-7-demethyl-6a-fluorotetracycline and the corresponding 6p- isomer have been synthesised and exhibit high activities compared to the parent tetracyclines. Acquired resistance to tetracyclines has been an impediment to their clinical use and in this context semi-synthetic studies which have already been very extensive have resulted in the introduction of valuable compounds such as minocycline. 

Blank H, Cullen SI, Cataland PM (1968) Photosensitivity studies with demethyl-chlortetra-cycline and doxycycline. Arch Dermatol 97 1-2 Bojs G, Moller H (1974) Eczematous contact allergy to oxytetracycline with cross-sensitivity to other tetracyclines. Berufsdermatosen 22 202-208 Boman G, Nilsson BS, Saerens EJ (1973) Protein binding of rifampicin. Scand J Respir Dis [Suppl] 84 40-44... 

Substituted derivatives of tetracyclines for which ribosomal or export-based resistance has not been exhibited. N.N-dimethylgly-cylamido derivatives of minocycline and 6-demethyl-6-deoxytc-itacycline are potent, new wide-spectrum antibiotics see Chapter 21. 

Chloro-6- demethyl-4- dedimethyl- amino- tetracycline 0.80 + Dull orange Green... 

Chloro-6- demethyl-5a,- 6-anhydro- tetracycline 0.94 -1- Red- orange Orange... 

Hydroxy-7- 0.00 chloro-6-demethyl-tetracycline -1- Orange Orange... 

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