Carbon-13 nmr spectra of 5β-steroidal sapogenins. Reassignment of the F-ring carbon signals of (25)-spirostans

Three Steroids with Unique Structural Feature of 5.BETA.-Spirostan-1.BETA.,3.BETA.,17.ALPHA.-trihydroxyl from Reineckia carnea

“…C-NMR and distortionless enhancement by polarization transfer (DEPT) spectrum of 1 showed a quaternary carbon signal at d 110.6, which is the characteristic C-22 of a spirostanol skeleton. 17) On comparison between the 13 C-NMR spectrum of 1 with that of rhodeasapogenin [25(S)-5b-spirostan-1b,3b-diol], 14,18) the signal due to the C-17 carbon, which was observed at d 63.1 (CH) in rhodeasapogenin, appeared at d 89.6 as a quaternary carbon signal, accompanied by downfield shifts of the signals due to C-13 (ϩ5.5 ppm), C-16 (ϩ9.6 ppm), and C-20 (ϩ2.7 ppm) and upfield shifts of signals due to C-12 (Ϫ10.4 ppm), C-14 (Ϫ3.5 ppm), and C-21 (Ϫ5.9 ppm); in addition, the molecuThree Steroids with Unique Structural Feature of 5b b-Spirostan1b b,3b b,17a a-trihydroxyl from Reineckia carnea Interpretation of the heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond connectivity (HMBC), and correlation spectroscopy (COSY) spectrum allowed us to assign all the signals of compound 1 unambiguously (for the key HMBC correlations, see Fig. 2).…”

Steroids from the Roots of Asparagus officinalis and Their Cytotoxic Activity

“…The present study undertook the isolation and structural elucidation of one new steroidal saponin, namely Sarsasapogenin O ( 1, Figure 1), along with seven known steroids, asparagoside A ( 2 ) (Tori et al 1981), (25 R )‐5β‐spirostan‐3β‐ol 3‐ O ‐β ‐ D‐glucopyranoside ( 3 ) (Seo et al 1978), sarsasapogenin ( 4 ) (Tori et al 1981), sarsasapogenone ( 5 ) (Loader et al 2003), (25 S )‐neospirost‐4‐en‐3‐one ( 6 ) (Achenbach et al 1996), 25 S ‐spirosta‐1, 4‐dien‐3‐one ( 7 ) (Kimura et al 1967), and stigmasterol ( 8 ) from the roots of A. officinalis . The structures of steroids were elucidated on the basis of spectral and chemical methods.…”

A New Leishmanicidal Saponin from Brunfelsia grandiflora

“…A new furostan-type saponin, 1, was isolated from the methanolic extract of B. grandiflora leaves, together with three known compounds: chlorogenic acid, scopoletin and 3- C-NMR data of 1-a were identical to those of neotigogenin, 5) which has a spirostanol structure.…”

“…A) was subjected to column chromatography on silica gel (developing solvent: gradient with chloroform-methanol system) to afford 20 Fractions (FR. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Fractions eluted with 30-40% methanol/chloroform (FR.…”