2-Hydroxy-1-Methoxyaporphine

Purification and characterization of aporphine alkaloids from leaves of Nelumbo nucifera Gaertn and their effects on glucose consumption in 3T3-L1 adipocytes.[Pubmed:24577311]

Int J Mol Sci. 2014 Feb 26;15(3):3481-94.

Aporphine alkaloids from the leaves of Nelumbo nucifera Gaertn are substances of great interest because of their important pharmacological activities, particularly anti-diabetic, anti-obesity, anti-hyperlipidemic, anti-oxidant, and anti-HIV's activities. In order to produce large amounts of pure alkaloid for research purposes, a novel method using high-speed counter-current chromatography (HSCCC) was developed. Without any initial cleanup steps, four main aporphine alkaloids, including 2-Hydroxy-1-Methoxyaporphine, pronuciferine, nuciferine and roemerine were successfully purified from the crude extract by HSCCC in one step. The separation was performed with a simple two-phase solvent system composed of n-hexane-ethyl acetate-methanol-acetonitrile-water (5:3:3:2.5:5, v/v/v/v/v). In each operation, 100 mg crude extracts was separated and yielded 6.3 mg of 2-Hydroxy-1-Methoxyaporphine (95.1% purity), 1.1 mg of pronuciferine (96.8% purity), 8.5 mg of nuciferine (98.9% purity), and 2.7 mg of roemerine (97.4%) respectively. The chemical structure of four aporphine alkaloids are identified by means of electrospray ionization MS (ESI-MS) and nuclear magnetic resonance (NMR) analysis. Moreover, the effects of four separated aporphine alkaloids on insulin-stimulated glucose consumption were examined in 3T3-L1 adipocytes. The results showed that 2-Hydroxy-1-Methoxyaporphine and pronuciferine increased the glucose consumption significantly as rosiglitazone did.

Identification and characterization of potent CYP2D6 inhibitors in lotus leaves.[Pubmed:24561383]

J Ethnopharmacol. 2014 Apr 11;153(1):190-6.

ETHNOPHARMACOLOGICAL RELEVANCE: The herb of lotus (Nelumbo nucifera) leaves is a commonly used traditional Chinese herbal medicine that is utilized for the treatment of sunstroke, to assuage thirst, and to cure both diarrhea and fever in China. Modern pharmacological studies have demonstrated that the herb exhibits various pharmacological effects, such as anti-hyperlipidemia, anti-obesity, anti-oxidant, anti-HIV, anti-microbial, and anti-hypoglycemic activities. Currently, the herb is becoming more popular in China as a "tea drink" or as a main ingredient of some herbal formulations, which implies that the herb and/or its products are now more likely to be concurrently administered with conventional medicines for losing body weight and reducing blood lipids. However, its potential inhibitory effect on human cytochrome P450 (CYP) has not been systemically investigated to date. The present study was performed to assess the potential inhibitory effects of lotus leaf alcoholic extract (LAE), its major fractions, and its main compounds on five CYP isoenzymes (CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4) in vitro. MATERIAL AND METHODS: Five probe substrates were incubated with human liver microsomes in the presence or absence of the LAE, the alkaloid fraction (AF), the flavonoid fraction (FF), or the individual aporphine alkaloids, namely, nuciferine (NF), N-nornuciferine (N-NF), and 2-Hydroxy-1-Methoxyaporphine (HMA). After the incubation, the relative metabolites of the substrates were analyzed using LC-MS/MS. RESULTS: The results showed that the LAE strongly inhibited CYP2D6 with an IC50 value of 12.05microg/mL and weakly inhibited other isoenzymes. In addition, FF was found to weakly inhibit CYP2D6, whereas AF exerted a markedly higher inhibitory effect on CYP2D6 activity with an IC50 value of 0.96microg/mL. The three aporphine alkaloids isolated from the AF (NF, N-NF, and HMA) significantly inhibited CYP2D6 with IC50 values of 3.78, 3.76, and 3.15microM, respectively. Their Lineweaver-Burk plots and Dixon plots showed that NF, N-NF, and HMA competitively inhibited CYP2D6 activity with Ki values of 1.88, 2.34, and 1.56microM, respectively. CONCLUSION: The study revealed that the alkaloid compounds in lotus leaves exert a potent inhibitory effect on CYP2D6 isoenzyme. The possible drug interactions of the leaves and their preparations with conventional medicines should thus be taken into account.

[HPLC determination of 2-hydroxy-1-methoxyaporphine, pronuciferine, nuciferine and roemerine in Nelumbo nucifera and its alkaloid fraction].[Pubmed:18841775]

Zhongguo Zhong Yao Za Zhi. 2008 Jul;33(14):1713-6.

OBJECTIVE: To establish an HPLC method for the determination of four alkaloids, i.e., 2-Hydroxy-1-Methoxyaporphine, pronuciferine, nuciferine and roemerine, in Nelumbo nucifera and its alkaloid fraction. METHOD: The determination was carried out at 35 degrees C on a Hypersil C18 column (4.6 mm x 250 mm, 5 microm), eluting with acetonitrile-water containing 0.1% triethylamine as mobile phases in gradient mode. The flow rate was 1.0 mL x min(-1) and detection at the wavelength was set at 270 nm. RESULT: The linear ranges of 2-Hydroxy-1-Methoxyaporphine, pronuciferine, nuciferine and roemerine were 0.110-0.658 microg (r = 0.9995), 0.0210-0.126 microg (r = 0.9995), 0.103-0.618 microg (r = 0.9998), 0.085 6-0.514 microg (r = 0.9995), with the average recoveries (n=6) were 101.5%, 99.14%, 99.21% and 98.41% for the alkaloid fraction of N. nucifera and 99.53%, 100.5%, 97.51% and 100.1% for N. nucifera respectively. CONCLUSION: The determination results of the three batches of samples showed that the method was easy and accurate which could be used to determine the contents of four components in N. nucifera and its alkaloid fraction.