Mass spectra of isosteviol derivatives: I. Fragmentation of isosteviol derivatives having a Schiff base fragment on C4 under electron impact

Dose‐dependent pharmacokinetics and tentative identification of urine metabolites from an isosteviol derivative with anti‐hepatitis B activity in rats

“…A fragment ion appeared at m/z 305.05 (C 19 H 33 N 2 O), probably from loss of a methyl radical and CO from the D‐ring of compound 1 . Similar fragmentation was also reported for an ester of isosteviol (Babaev, Musin, Strobykina, Kataev, & Gavrilov, ) and an isosteviol derivative with a Schiff base fragment at C‐4 (Musin et al, ). The fragment at m/z 273.12 (C 19 H 29 O) was possibly a result of cleavage of the C–N bond at position 4 of compound 1 with no migration of positive charge to the nitrogen (Musin et al, ).…”

“…Similar fragmentation was also reported for an ester of isosteviol (Babaev, Musin, Strobykina, Kataev, & Gavrilov, ) and an isosteviol derivative with a Schiff base fragment at C‐4 (Musin et al, ). The fragment at m/z 273.12 (C 19 H 29 O) was possibly a result of cleavage of the C–N bond at position 4 of compound 1 with no migration of positive charge to the nitrogen (Musin et al, ). The peak at m/z 146.99 (C 11 H 15 ) possibly arose from the fragment ion at m/z 273.12 (C 19 H 29 O) following cleavage of C8–C14 and C9–C11 bonds and loss of a methyl attached at C‐4 in a manner similar to the fragmentation reported for cholesterol (Piehowski et al, ).…”

“…The probable loss of a methyl radical from the fragment at m/z 146.99 resulted in a peak at m/z 133.03 (C 10 H 13 ). The fragment ion at m/z 102.98 (C 4 H 11 N 2 O) was probably generated from the cleavage of C4–C5 and C1–C10 bonds of compound 1 that was similar to the reported fragmentation pattern of 4 α ,2‐hydroxybenzylideneamino derivatives of isosteviol (Musin et al, ). The fragment ion at m/z 75.02 (C 2 H 7 N 2 O) was possibly due to either cleavage of the position C–N bond at C‐4 of compound 1 or migration of the hydrogen from the β carbon to the nitrogen of the ureido moiety which produced a positive charged ion (Babaev et al, ).…”

DPPH Scavenging Property of Active Principles from Soft Coral Sarcophyton Flexuosum Tixier-Durivault

“…Isosteviol is a tetracyclic diterpenoid with a beyerane skeleton which was already reported from a natural source Stevia rebaudiana bertoni [27,28]. A large number of synthetic derivatives of isosteviol were reported, and some derivatives were found to exhibit biological activity [29]. The cardioprotective effect of isosteviol is comparable to that of traditional cardioprotective agents [30].…”