Chemical-Structural Properties of Tetracycline Derivatives. 10. The 6-Thiatetracyclines

Article abstract of DOI:10.1021/ja00543a020

Crystal structure determinations for three tetracycline derivatives, 6-thiatetracycline, 6-STC, 5a-epi-6-thiatetracycline, 5a-epi-6-STC, and 11a-hydroxy-12a-dehydroxy-6-thiatetracycline, 11a-OH-12a-DOH-6-STC, have been carried out with data from cooled crystals (T ca. 120 K).Their respective space groups, lattice parameters (120 K), and the resultant conventional residuals are as follows: <*>, a = 5.5360 (3) Angstroem, b = 19.538 (2) Angstroem, c = 17.540 (2) Angstroem, β = 99.93 (1) deg, R = 0.043; <*>, a = 8.934 (1) Angstroem, b = 10. 420 (2) Angstroem, c = 12.726 (2) Angstroem, α = 94.73 (1) deg, β = 97.68 (1) deg, γ = 104.95 (1) deg, R = 0.053; <*>, a = 12.049 (1) Angstroem, b = 10.698 (1) Angstroem, c = 17.240 (2) Angstroem, β = 93.46 (1) deg, R = 0.050.Synthetic pathways for 5a-epi-6-STC and 11a-OH-12a-DOH-6-STC are described.Partition coefficients for 6-STC and 5a-epi-6-STC in the CHCl3-H2O system were determined and indicate that the differences in their antibacterial activity are not the result of lipid absorption of the latter derivative.