A pregnane steroid from Aglaia lawii and structure confirmation of cabraleadiol monoacetate by X-ray crystallography

Dammarane triterpenes from the resins of <i>Commiphora confusa</i>

“…The IR spectrum revealed hydroxyl and ester carbonyl absorptions at 3450 cm -1 and 1725 cm -1 , respectively. The 1 H-and 13 C-NMR data were virtually identical to those reported for cabraleadiol 3-acetate (4) [11,12], a compound previously isolated from Commiphora dalzielii [2].…”

“…Based on NMR data, Aalbersberg and Singh [14] reported the configurations of the two stereocenters in the side chain of 4 as (20S,24R) while Hisham et al [11] proposed (20S,24S). However recently using X-ray diffraction analysis, the structure of compound 4 was determined as (3R,20S,24S)-3-acetoxy-20,24-epoxy-25-hydroxydammarane [12]. The occurrence of dammarane triterpenes in both Meliaceae and Burseraceae indicates a close chemotaxonomic relationship of the two families [2].…”

Two Novel abeo‐Dammaranes with a Six‐Membered Acetal Moiety from Aglaia perviridisHiern

“…Together with 1 and 2, the six known dammaranes cabraleone [6], cabraleadiol [7], cabraleadiol 3-acetate [8], cabralealactone [9], cabraleahydroxylactone [10], and cabraleahydroxylactone 3-acetate [11] were isolated from the same extract. Their structures were elucidated by spectral data and comparison with literature values.…”

“…25)abeo-dammaran-3-ol acetate (2). The six known dammaranes cabraleone (¼ (24S)-20,24-epoxy-25-hydroxydammaran-3-one) [6], cabraleadiol (¼ (3a,24S)-20,24-epoxydammarane-3,25-diol) [7], cabraleadiol 3-acetate (¼ (3a,24S)-20,24-epoxydammarane-3,25-diol 3-acetate) [8], cabralealactone (¼ (5a)-20-hydroxy-4,4,8,14-tetramethyl-3-oxo-18-norcholan-24-oic acid g-lactone) [9], cabraleahydroxylactone (¼ (3a,5a)-3,20-dihydroxy-4,4,8,14-tetramethyl-18-norcholan-24-oic acid g-lactone) [10], and cabraleahydroxylactone 3-acetate (¼ (3a,5a)-3-(acetyloxy)-20-hydroxy-4,4,8,14-tetramethyl-18-norcholan-24-oic acid g-lactone) [11], were also isolated from the same extract. According to our knowledge, this is the first report of the chemical constituents from A. perviridis.…”

“…These spectral data were quite similar to those of cabraleone [6], cabralealactone [9], and (20R)-23(24 ! 25)abeo-20,24-dihydroxy dammaran-9-one [12] except for the resonances attributable to the side chain [8] [12] [13]. Hence, 1 was expected to be a dammarane with a C¼O group at C(3).…”