Cephalotaxine-type alkaloids from the seeds of Cephalotaxus fortunei and their cytotoxic activities

Enantiomeric Cephalotaxus alkaloids from seeds of Cephalotaxus oliveri

“…Its molecular formula was determined as C 20 H 25 NO 5 from HRESIMS m/z = 360.1807 [M+H] + (Additional file 1 : S23). The 1 H NMR data (Table 1 , Additional file 1 : S20) were very similar to those of the known alkaloid cephalofortine C [ 11 ], with exception for the downfield H-3 signal ( δ H 5.70, Δδ C + 0.97) and a methyl signal ( δ H 1.41). Additionally, compared to cephalofortine C, 4 had an acetyl group in its 13 C NMR ( δ C 20.4, 171.9).…”

Cephalotaxine-type and homoerythrina-type alkaloids with antiproliferative effects from Cephalotaxus fortunei

“…The above data indicated that compound 15 is a cephalotaxine-type alkaloid with the same skeleton as cephalofortine B (16). 19 Compared with the 13 C NMR data of 16 , the obviously upfield shifted signals of C-11 ( δ C 33.6), and the molecular formula C 17 H 21 NO 4 , indicated that a hydroxy group at the C-11 position was loss in compound 15 .…”

“…The 6,7-dihydroxy substitution was confirmed by the deshielded signals at C-7 and C-8. Compared with the 13 C NMR data of cephalofortine F ( 4 ), the strongly downfield shifted signals of C-5 ( δ 85.1), C-8 ( δ 78.6) and C-10 ( δ 63.9) allowed us to assign the N -oxide structure, 19 thus establishing the gross structure.…”

“…The obtained known alkaloids were identified as cephalofortine F ( 4 ), 19 cephalofortuneine ( 5 ), 18 2-epicephalofortuneine ( 6 ), 23 3-epiwilsonine ( 7 ), 24 wilsonine ( 8 ), 18 epischelhammercine B ( 9 ), 25 fortunine ( 10 ), 22 fortuneicyclidin A ( 12 ), 20 cephalocyclidin A ( 14 ), 21 cephalofortine B ( 16 ), 19 cephalotines A ( 18 ) and B ( 19 ), 22 4-hydrocephalotaxine ( 20 ), 23 cephalotine D ( 21 ), 22 epicephalotaxine ( 22 ), 26 cephalotaxine ( 23 ), 27 acetylcephalotaxine ( 24 ), 22 cephalofortine A ( 25 ), 19 11-hydroxycephalotaxine ( 26 ), 19 (−)-cephalezomine H ( 27 ), 19,28 cephalezomine H ( 28 ), 28,29 demethylcephalotaxinone ( 29 ), 25 drupacine ( 30 ), 30 hainanensine ( 31 ) 31 and cephalancetine C ( 32 ) 32 via comparison of the reported spectroscopic data. It deserved to be mentioned that 14 and its hydrochloride salt ( 14a ) were respectively obtained during the isolation.…”

“…The coupling constant of H-3 and Organic & Biomolecular Chemistry Paper H-4 ( J = 11.4 Hz) indicated that H-3 and H-4 were trans, assigning H-3 to be β-orientation. 19 The absolute configuration of 15 was determined by the similarity of its experimental and the calculated ECD of (2S,3R,4S,5R)-15a. The structure of 15 was assigned as shown and named as 11-deoxycephalofortine B.…”