Caulophylline

[Effect of nucleotides on N-methylcytisine and dimethyltubocurarine binding by the nicotinic acetylcholine receptors of the optic ganglia in the squid B. magister].[Pubmed: 2790167]

Biull Eksp Biol Med. 1989 Jun;107(6):706-9.

The effect of nucleosides mono-, di-, and triphosphates on binding of 3H-N-Methylcytisine and 14C-tubocurarine to nAChR from squid optical ganglia were investigated.
METHODS AND RESULTS:
It was found, that ATP and GTP potentiate the specific binding of 3H-N-Methylcytisine and inhibit the one of 14C-tubocurarine. While conducting the photoaffinity modification of nACHR by 3H-azidomethylcytisine in the presence of ATP the increase of specific incorporation of label was observed in comparison with control. Molecular weight of labeled receptor complex and subunit, carrying the binding site was the same as the original.

[N-methylcytisine--a selective ligand of nicotinic receptors of acetylcholine in the CNS].[Pubmed: 3689962]

Biull Eksp Biol Med. 1987 Dec;104(12):690-2.

The ability of cytisine and its N-methyl derivatives to bind to nicotinic acetylcholine receptors (nAChR) from different tissues was studied.
METHODS AND RESULTS:
Cytisine and N-Methylcytisine have high affinity (KD = 50 nM) to nAChR from squid optical ganglia. N,N-dimethylcytisine did not show high affinity to this receptor. In the case of nAChR from T. marmorata, cytisine was the only effective inhibitor of 14C-tubocurarine specific binding (Ki = 700 nM). N-methyl- and N,N-dimethylcytisine did not displace 14C-tubocurarine at a concentration of 0.1 mM.
CONCLUSIONS:
The results obtained indicate that there are some differences in the structure of nAChR binding sites from squid and T. marmorata optical ganglia.

Nematicidal Activities of ( – )--Methylcytisine and ( – )-Anagyrine from Sophora flavescens against Pine Wood Nematodes[Reference: WebLink]

Agric. Biol. Chem., 1989, 53(8):2287-8.

Although the effects of ( - )-N-methyleytisine (1) on the motility of Angiostrongylus cantonensis, Dipylidium caninum and Fasciola hepatica have already been investigated by Te r ada e t al.,5) the activities of ( -)-N-Methylcytisine (1) and ( -)-anagyrine (2) against pl ant parasitic nematodes have never been reported.
METHODS AND RESULTS:
The inhibitory effects of ( -)-N-methyleytisine and ( -)-anagyrine, together with ( -)-cytisine and ( - )-nicotine (Sigma Chern. Co.), on the propaga t ion of the pine wood nematode, Bursaphelenchus xylophilus, were examined by the sameprocedure as that described by Kawazu e t aU) As shown in Tables I and I I , the nematicidal activity of ( -) -Nmethylcytisine was about twice that of ( - )-anagyrine, but a half that of ( - )-cytisine and ( - )-nicotine.
CONCLUSIONS:
This result of ( - )-N-Methylcytisine and ( -)-anagyrine being the primary nematicidal constituents among various alkaloids contained in the root of S. jiavescens2 • 6 ) suggests that the cytisine-type structure common to both alkaloids (1 and 2) is favorable to show the nematicidal activity.

J Chromatogr B Analyt Technol Biomed Life Sci. 2015 May 15;990:118-24.

Determination of N-methylcytisine in rat plasma by UPLC-MS/MS and its application to pharmacokinetic study.[Pubmed: 25864013]

In this work, a sensitive and selective UPLC-MS/MS method for determination of N-Methylcytisine in rat plasma is developed.
METHODS AND RESULTS:
After addition of hordenine as an internal standard (IS), protein precipitation by acetonitrile-methanol (9:1, v/v) was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH HILIC (2.1 mm×100mm, 1.7μm) with acetonitrile (containing 10mM ammonium formate) and water (containing 0.1% formic acid and 10mM ammonium formate) as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reaction monitoring (MRM) mode was used for quantification using target fragment ions m/z 205.1→58.0 for N-Methylcytisine, and m/z 166.1→121.0 for IS. Calibration plots were linear throughout the range 2-2000ng/mL for N-Methylcytisine in rat plasma. Mean recoveries of N-Methylcytisine in rat plasma ranged from 86.1% to 94.8%. RSD of intra-day and inter-day precision were both<13%. The accuracy of the method was between 94.5% and 109.4%.
CONCLUSIONS:
The method was successfully applied to pharmacokinetic study of N-Methylcytisine after either oral or intravenous administration. For the first time, the absolute bioavailability of N-Methylcytisine was reported as high as 55.5%.

Anal Bioanal Chem. 2013 May;405(13):4409-17.

Primary constituents of blue cohosh: quantification in dietary supplements and potential for toxicity.[Pubmed: 23420136]

Dietary supplements containing dried roots or extracts of the roots and/or rhizomes of blue cohosh (Caulophyllum thalictroides) are widely available. This botanical has a long history of use by Native Americans and its use continues to the present day.
METHODS AND RESULTS:
The primary constituents of blue cohosh are its alkaloids and saponins. The structures of the alkaloids magnoflorine, baptifoline, anagyrine, and N-Methylcytisine have been known for many years. The last 10 years have seen a great increase in isolation and identification of the large number of saponins present in blue cohosh. Important developments in nuclear magnetic resonance techniques have contributed substantially to the increase in elucidation of the structures of the complex saponins. Several authors have described quantitative methods for both the alkaloids and saponins in blue cohosh. Such methods have made it possible to quantify these constituents in dietary supplements containing this botanical ingredient. Concentrations of both alkaloids and saponins vary substantially in dietary supplements of blue cohosh.
CONCLUSIONS:
The nicotinic alkaloid, N-Methylcytisine, a potent toxicant, has been found in all dietary supplements of blue cohosh analyzed. The teratogenic alkaloid anagyrine has been found in some but not all dietary supplements.