Biflavonoid constituents of Campylospermum mannii

A Nitrile Glucoside and Biflavones from the Leaves of Campylospermum excavatum (Ochnaceae)

“…The 1 H-NMR spectrum ( Table 1) The above configuration was in agreement with a biflavone comprising one luteolin and one apigenin unit linked through a C-O-C bond such as ochnaflavone (C(3 0 )-O-C(4‴) linkage) [22] [23] or loniflavone (C(4 0 )-O-C(4‴) linkage). [24] Observation on the 2D 1 H, 1 H-COSY-LR spectrum of correlations between the methoxy H-atoms with H-C (6) and H-C(8) allowed to deduce that the methoxy group was linked to C (7). This was further confirmed by the correlations on the 2D 1 H, 13 C-HMBC spectrum between both the methoxy H-atoms and H-C(6) with C(7).…”

“…In this purpose, a 2D 1 H, 13 C-HMBC NMR experiment where a low-pass J filter eliminates one-bond J(C,H) responses and permits the measurement of long-range J(C,H) coupling constants was performed. [20] [21] This resulted in the observation of a 3 J (H-C(7),C(1)) of 8 Hz and a 3 J(H-C(7),C(3)) of 5 Hz, compatible with a trans relationship between H-C (7) and C(1) and a cis relationship between H-C(7) and C(3) ( Fig. 1).…”

“…This kind of nitrile glycosides have already been characterized from other Campylospermum species such as campyloside A previously isolated from the stem roots of C. glaucum. [3] However, the structure determination of lanceolin C or campyloside A was uncomplete, since the configuration of the double bond D 2 (7) and the absolute configuration have not been established. In this purpose, a 2D 1 H, 13 C-HMBC NMR experiment where a low-pass J filter eliminates one-bond J(C,H) responses and permits the measurement of long-range J(C,H) coupling constants was performed.…”

“…The main metabolites isolated from this genus are nitrile glucosides, flavonoids and biflavonoids as well as indole alkaloids . These compounds are often isolated from different species of Ochnaceae and used as chemotaxonomic markers to distinguish each genus within this botanical family.…”

Biflavanones, Chalconoids, and Flavonoid Analogues from the Stem Bark of Ochna holstii

“…The structures of the isolated compounds were elucidated by 1D and 2D NMR spectroscopic and mass spectrometric analyses. The known compounds were identified as ouratein D ( 6 ), 15 isochamaejasmin A ( 7 ), 16 , 17 7′,7″-di- O -methylisochamaejasmin ( 8 ), 18 campylospermone A ( 9 ), 19 liquiritigeninyl-(1-3,II-3)-naringenin ( 10 ), 8 isoliquitigenin ( 11 ), 20 terminalionone ( 12 ), 21 flavumchalcone ( 13 ), 22 lophirone F ( 14 ), 23 2,3-dihydrocalodenin B ( 15 ), 3 and calodenin B ( 16 ), 24 , 25 by comparison of their spectroscopic data with reported data. …”