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

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

“…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).…”

“…The conversion of 3β-hydroxy-5-ene steroids leads to both 3-oxo-4-enes as the major products and 6-oxy metabolites as the minor ones with Helix pomatia (14,(16)(17)(18)(19)(20)(21). 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.…”

“…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).…”

Novel Fragmentation Pathways of Anionic Adducts of Steroids Formed by Electrospray Anion Attachment Involving Regioselective Attachment, Regiospecific Decompositions, Charge-Induced Pathways, and Ion–Dipole Complex Intermediates

“…In recent years, ESI-MS has been widely used for steroid analysis [32][33][34]. Currently, LC coupled to ESI-MS [35][36][37], ESI-MS/MS, or APCI-MS [38] are the favored techniques to analyze steroid mixtures. These techniques have the advantage of high sensitivity and modest sample preparation requirements.…”

New Cytotoxic Steroid from Stachyurus imalaicus var. himalaicus

“…The new steroid 1, a polyoxygenated 3-oxo-4-ene sterol, was found to have cytotoxic activity against human Hela cell lines in vitro with an IC 50 value 2.5 µg/mL. Literature reportes indicate that 3-oxo-4-ene sterols (OH-substituted at C 1~15 hydrocarbon chain) have been utilized in the treatment of conditions associated with rapidly growing cells and cancers such as melanoma [9] and except for the estrogens, many steroid hormones have the 3-oxo-4-ene (∆ 4 )-structure [10]. In addition to 1, the three known ecdysteroids 20-hydroxyecdysone (2) [11], 20-hydroxyecdysone-20,22-monoacetonide (3) [12] and polypodine B-20,22-monoacetonide (4) [13], were isolated from Stachyurus himalaicus var.…”