A direct stereoselective synthesis of 7β-hydroxytestosterone

Labaree, David; Hoyte, Robert M.; Hochberg, Richard B.

doi:10.1016/s0039-128x(97)00018-4

Cited by 23 publications

(14 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, no steroids with 3α-hydroxy-5-ene, 3α-hydroxy-5α or 5β-reduced, and 3-oxo-5α or 5β-reduced structure produced any by-products, which are accordance with a previous report (16). These results suggest that Helix pomatia also contains cholesterol oxidase in addition to 3β-hydroxysteroid oxidoreductase/3-oxosteroid-4,5-ene isomerase and 6-hydroxylase, 6-hydroxysteroid as additional enzymes (16)(17)(18)(20)(21)(22)(23)(24).…”

Section: Resultssupporting

confidence: 91%

“…These two actions suggest that they are caused by the presence of 3β-hydroxysteroid dehydrogenase/Δ 5-4 -ene steroid isomerase and 6-hydroxylase as additional enzymes (17,18,20) in the Helix pomatia extracts. The generation of 3-oxo-4-ene steroids might be converted by cholesterol oxidase because 3β-hydroxysteroid dehydrogenase does not require oxygen (16,17,(21)(22)(23)(24), but this has not been proven. The variability of the selectivity and reactivity of Helix pomatia is also affected by the reaction temperature, incubation time pH, and amount of enzyme added (14,(25)(26)(27).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Systematic Error in Gas Chromatography-Mass Spectrometry–Based Quantification of Hydrolyzed Urinary Steroids

Moon

et al. 2010

Cancer Epidemiology, Biomarkers &Amp; Prevention

View full text Add to dashboard Cite

Gas chromatography-mass spectrometry-based metabolite profiling can lead to an understanding of various disease mechanisms as well as to identifying new diagnostic biomarkers by comparing the metabolites related in quantification. However, the unexpected transformation of urinary steroids during enzymatic hydrolysis with Helix pomatia could result in an underestimation or overestimation of their concentrations. A comparison of β-glucurondase extracted from Escherichia coli revealed 18 conversions of 84 steroids tested as an unexpected transformation under hydrolysis with β-glucuronidase/arylsulfatase extracted from Helix pomatia. In addition to the conversion of 3β-hydroxy-5-ene steroids into 3-oxo-4-ene steroids, which has been reported, the transformation of 3β-hydroxy-5α-reduced and 3β-hydroxy-5β-reduced steroids to 3-oxo-5α-reduced and 3-oxo-5β-reduced steroids, respectively, was newly observed. The formation of by-products was in proportion to the concentration of substrates becoming saturated against the enzyme. The substances belonging to these three steroid groups were undetectable at low concentrations, whereas the corresponding by-products were overestimated. These results indicate that the systematic error in the quantification of urinary steroids hydrolyzed with Helix pomatia can lead to a misreading of the clinical implications. All these hydrolysis procedures are suitable for study purposes, and the information can help prevent false evaluations of urinary steroids in clinical studies. Cancer Epidemiol Biomarkers Prev; 19(2); 388-97. ©2010 AACR.

show abstract

Section: Resultssupporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Systematic Error in Gas Chromatography-Mass Spectrometry–Based Quantification of Hydrolyzed Urinary Steroids

Moon

et al. 2010

Cancer Epidemiology, Biomarkers &Amp; Prevention

View full text Add to dashboard Cite

show abstract

“…Because the treatment of 24R,25(OH) 2 D 3 with oxidizing reagents, such as pyridinium chlorochromate gave poor results in the preparation of compound A; large amounts of by-products were formed, the enzymatic synthesis of compound A using ChO, which has a broad substrate specificity and can oxidize various steroids [16,17], was undertaken. The incubation of 24R,25(OH) 2 D 3 with ChO in air at 37 • C gave a product, which co-eluted with compound A in the normal-(t R 8.3 min) and reversed-phase HPLC (t R 9.0 min).…”

Section: Identification Of 3-oxo-product Derived From Intermediate Dumentioning

confidence: 99%

Analysis of C-3 epimerization in (24R)-24,25-dihydroxyvitamin D3 catalyzed by hydroxysteroid dehydrogenase

Higashi

Sakajiri

Shimada

2004

Journal of Pharmaceutical and Biomedical Analysis

View full text Add to dashboard Cite

“…1). Cholesterol oxidase (ChO) has a broad specificity and therefore can convert various 5 -steroids to their 4 -forms [6,7]. With this background information, we first examined the usefulness of the conversion of 5 -steroids to 4 -steroids with ChO for the detection responses in LC-APCI-MS (Fig.…”

Section: Introductionmentioning

confidence: 99%

Enzymic conversion of 3β-hydroxy-5-ene-steroids and their sulfates to 3-oxo-4-ene-steroids for increasing sensitivity in LC–APCI-MS

Higashi

Takayama

Shimada

2005

Journal of Pharmaceutical and Biomedical Analysis

View full text Add to dashboard Cite

A direct stereoselective synthesis of 7β-hydroxytestosterone

Cited by 23 publications

References 13 publications

Systematic Error in Gas Chromatography-Mass Spectrometry–Based Quantification of Hydrolyzed Urinary Steroids

Systematic Error in Gas Chromatography-Mass Spectrometry–Based Quantification of Hydrolyzed Urinary Steroids

Analysis of C-3 epimerization in (24R)-24,25-dihydroxyvitamin D3 catalyzed by hydroxysteroid dehydrogenase

Enzymic conversion of 3β-hydroxy-5-ene-steroids and their sulfates to 3-oxo-4-ene-steroids for increasing sensitivity in LC–APCI-MS

Contact Info

Product

Resources

About