Conformational change in two modifications of 2,4-dibromoestradiol

Cody, Vivian; DeJarnette, F.E.; Duax, W. L.; Norton, D. A.

doi:10.1107/s0567740871006046

Cited by 16 publications

(13 citation statements)

References 2 publications

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“…Angle C(3)-C(4)-C(5) appears to be larger than in steroids that have no substituent at C(4). This is also true for 2,4-dibromoestratrienediol (Cody, De Jar-4-FLUORO-1,3,5 ( 10)-ESTRATRIENE-3,17fl-DIOL-HEMIM ETHANOL nette, Duax & Norton, 1971) where this angle is 124 °, while with the bromo substituent at C(2) only it is 122 °. The bromo substituent at C(4) does create some distortion in the vicinity of C(4) due to its size, resulting in the torsion angle C(3)-C(4)-C(5)-C(10) of 6-8 ° showing greater deviation from the average value of about 2 °.…”

Section: Discussionmentioning

confidence: 77%

Structure of 4-fluoro-1,3,5(10)-estratriene-3,17β-diol–hemimethanol

Go¹,

Kartha²,

Neeman³

1982

Acta Crystallogr Sect B

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Abstract. ClsH23FO2.½CH3OH, triclinic, P1, a = 7.367 (1), b= 9.363 (6), c = 12.531 (1) A,, a= 89.31 (3), /? = 93.38 (1), y = 109.62 (3) ° , V = 812.8/k 3, Z = 2. The structure was solved by direct methods and refined by block-diagonal least squares to an R factor of 6.2% for 3043 observed reflections. The general features of the steroid are similar to those of other estratriene analogs. Molecules in the crystal are linked together in a head-to-tail fashion between the O at C(3) and at C (17), and sideways between the hydroxyls of the solvent and the steroid.Introduction. Tumor inhibitory effects on estrogen administration have been observed in breast and prostatic cancers and attempts have been made to obtain modified steroidal estrogens that will be useful in cancer chemotherapy. In this connection it is seen that in contrast to the biologically inactive bromo analog, 4-fluoroestratrienediol (4FE2) is a very highly active estrogen. The present crystallographic study of the structure and conformation of 4FE2 was undertaken to establish the stereochemical reason, if any, for the striking difference in biological activity of the two analogs.A crystal of about 1.3 × 0.8 × 0.3 mm crystallized from benzene was used to collect the diffraction data. The crystals are triclinic with space group P I. Lattice parameters were refined by a least-squares fit to a set of 24 measured reflections in a 0 range 10-34 ° (Cu Ka). Three-dimensional data were collected on an Enraf-Nonius CAD-4 automated diffractometer using Ni-filtered Cu Kct radiation by o.~--20 scans within the Cu sphere of 20 to 150 °. The measured intensities were converted to structure amplitudes in the usual manner, and corrected for Lorentz, polarization, and absorption effects. There were 3436 unique reflections measured, of which 3043 had intensities greater than 2o(1) and were used in the determination and refinement of the structure.

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Section: Discussionmentioning

confidence: 77%

Structure of 4-fluoro-1,3,5(10)-estratriene-3,17β-diol–hemimethanol

Go¹,

Kartha²,

Neeman³

1982

Acta Crystallogr Sect B

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“…We checked the quality of the models using PROCHECK (Table 1) (Bailey 1994). Coordinates for E2Br 2 and PCB were obtained from the Cambridge Structural Data Base (Cody et al 1971;McKinney and Singh 1988). The coordinates have been submitted to the PDB and given the PDB identification code 1G3M.…”

Section: Crystallographic Analysis Of a Hydroxylated Polychlorinated mentioning

confidence: 99%

Crystallographic analysis of a hydroxylated polychlorinated biphenyl (OH-PCB) bound to the catalytic estrogen binding site of human estrogen sulfotransferase.

Shevtsov

Petrotchenko

Pedersen

et al. 2003

Environ Health Perspect

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Certain hydroxylated polychlorinated biphenyls (OH-PCBs) inhibit the human estrogen sulfotransferase (hEST) at subnanomolar concentrations, suggesting a possible pathway for PCB toxicity due to environmental exposure in humans. To address the structural basis of the inhibition, we have determined the crystal structure of hEST in the presence of the sulfuryl donor product 3´-phosphoadenosine 5´-phosphate and the OH-PCB 4,4´-OH 3,5,3´,5´-tetraCB. The OH-PCB binds in the estrogen binding site with the position of the first phenolic ring in an orientation similar to the phenolic ring of 17β-estradiol. Interestingly, the OH-PCB does not bind in a planar conformation, but rather with a 30-degree twist between the phenyl rings. The crystal structure of hEST with the OH-PCB bound gives physical evidence that certain OH-PCBs can mimic binding of estrogenic compounds in biological systems.

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“…This is confirmed by X ray diffraction data for similar steroids. 7 Fragmentation of the [M + H] + ions under the ESI MS conditions. Collisional activation used to generate the [M + H] + ions from the title estranes results in their fragmentation involving the substituents R 1 O, R 2 O, and R 3 .…”

Section: Methodsmentioning

confidence: 99%