Mass spectral analysis of some derivatives and in vitro metabolites of steviol, the aglycone of the natural sweeteners, stevioside, rebaudioside A, and rubusoside.
Steviol (ent-13-hydroxykaur-16-en-19-oic acid), the aglycone of various plant-derived glycoside sweeteners consumed by human populations, is known to be mutagenic toward Salmonella tymphimurium strain TM677 when metabolically activated using a 9000 x g supernatant fraction derived from the liver of Aroclor 1254-pretreated rats. Mass spectral analysis of this diterpenoid and some analogs revealed characteristic patterns reflecting differential stereochemistry at the C/D rings and variations in the nature of the substituents present. Such information has been used to help identify several in vitro metabolites of steviol in conditions known to produce a mutagenic response, when analyzed by gas chromatography/mass spectrometry. The major pathways of such steviol mammalian metabolism proved to be allylic oxidation and epoxidation. 15-Oxosteviol, a product of oxidation of the major steviol metabolite, 15alpha-hydroxysteviol, was found to be a direct-acting mutagen [corrected].
Compadre
C M
CM
Program for Collaborative Research in the Pharmaceutical Sciences, College of Pharmacy, University of Illinois, Chicago 60612.
Hussain
R A
RA
Nanayakkara
N P
NP
Pezzuto
J M
JM
Kinghorn
A D
AD
D001711:Biotransformation; D004224:Diterpenes / Q000032:analysis* / Q000493:pharmacokinetics*; D045786:Diterpenes, Kaurane; D005960:Glucosides / Q000032:analysis*; D006027:Glycosides / Q000032:analysis*; D013058:Mass Spectrometry; D009153:Mutagens; D013549:Sweetening Agents / Q000032:analysis*; D013729:Terpenes / Q000032:analysis*
D004224:Diterpenes; D045786:Diterpenes, Kaurane; D005960:Glucosides; D006027:Glycosides; D009153:Mutagens; D013549:Sweetening Agents; D013729:Terpenes; C012043:stevioside; C012042:steviol; C025474:rebaudioside A; C056177:rubusoside