Quaternary Isoquinoline Alkaloids from Stephania cepharantha.

Abstract

From the quaternary alkaloidal fraction of the dried tubers of Stephania cepharantha, two new isoquinoline alkaloids, stecepharine and tetradehydroreticuline have been isolated along with the known compounds, magnoflorine, menisperine, steponine, cyclanoline, oblongine, cis-N-methylcapaurine and 2'-N-methylisotetrandrine. cis-N-Methylcapaurine (=9-O-methylstecepharine) was isolated as a natural product for the first time. Their structures were determined on the basis of spectroscopic evidence.

Identification of Alkaloids in Stephania hainanensis by Liquid Chromatography Coupled with Quadrupole Time‐of‐flight Mass Spectrometry

“…For compounds 3 and 8, the ions [M-NH(CH 3 ) 2 ] + and [CH 2 = N (CH 3 ) 2 ] + (m/z 58.066) suggested the presence of two methyl groups on the nitrogen. The isoquinoline fragment at m/z 192.10, the benzyl fragment at m/z 107.048 and other diagnostic ions at m/z 237.089, 175.074 and 143.048 were consistent with those of oblongine, which has been reported in Stephania cepharantha (Tanahashi et al, 2000;Singh et al, 2014). Compounds 3 and 8 were therefore tentatively identified as oblongine with a hexose and oblongine, respectively.…”

“…The RDA fragment of compound 32 at m/z 222.1121 was 16 Da higher than that of compound 24 , and it further lost CH 3 OH to produce the fragment at m/z 190.0849, thus suggesting that the OH was attached at a vicinal position to the OCH 3 groups on ring A. The compound with the OH group at C‐4, named 9‐ O ‐methylstecepharine, was consistent with the earlier information, and it has been isolated from Stephania cepharantha (Tanahashi et al , ). Therefore, compound 32 was tentatively identified as 9‐ O ‐methylstecepharine.…”

“…Compound 9 was assumed to be an aporphine alkaloid with a dimethylamine group based on the diagnostic ions [M–NH(CH 3 ) 2 ] + and [CH 2 = N(CH 3 ) 2 ] + . The characteristic ions were consistent with those of magnoflorine (Sim et al , ), which has already been reported in several Stephania plants (Tanahashi et al , ; Semwal et al , ). The identification was confirmed by comparison with the reference standard, and compound 9 was therefore identified as magnoflorine.…”

Acetylcholinesterase inhibitors from Stephania venosa tuber

“…The 13-H signal at 3.14 showed a large coupling constant (10.0 Hz) with the signal of 13a-H indicating that this proton was at axial position. Cyclanoline has also been found in S. elegan (Singh et al 1981) and S. cepharantha (Tanahashi et al 2000).…”

The genus Stephania (Menispermaceae): Chemical and pharmacological perspectives

“…Stephaoxocanine, stephaoxocanidine, romorphinane, cepharanthine, cepharanoline, steponine, isotetrandrine, berbamine, stecepharine, dehydroreticuline (11), magnoflorine, menisperine, oblongine, cyclanoline, cis-N-methylcapaurine, sinomenine, cephamerphinanine, D-glucopyranoside, 2 -N-methylisotetrandrine, N-methyl stesakine chloride (12), stesakine 9-O-␤-Dglucoside (13), N-methylasimilobine-2-O-␤-D-glucopyranoside (14), cephamonine, aromoline, zippelianine, cepharamine, aknadinine (15), aknadicine (16), cephatonine, (−)-cycleanine (28), obamegine, berbamine, isocorydine, anolobine, cotypalline, stepharine (9), (+)-reticuline (17), obaberine, homoaromoline, fangchinoline, tetrandrine (18), cephamuline Nakamura et al, 1992;Sugimoto et al, 1993Sugimoto et al, , 1988Kashiwaba et al, 1996Kashiwaba et al, , 1997Kashiwaba et al, , 2000Kashiwaba et al, , 1998Kashiwaba et al, , 1994Nakaoji et al, 1997;Tanahashi et al, 2000), berbamine and aromorine (Akasu et al, 1976).…”