Characterization and simultaneous quantification of biological aporphine alkaloids in Litsea cubeba by HPLC with hybrid ion trap time‐of‐flight mass spectrometry and HPLC with diode array detection

Abstract

The root and rhizome of Litsea cubeba (Lour) Pers., named 'Dou-chi-jiang' in Chinese, has been traditionally used for treatment of cardiovascular and cerebrovascular diseases, rheumatic arthralgia, and other diseases in China. Aporphine alkaloids are its characteristic ingredients and responsible for its bioactivities, especially anti-inflammatory and analgesic effects. A sensitive and reliable high-performance liquid chromatography with diode array detection-tandem mass spectrometry method was developed for characterization and simultaneous determination of biological aporphine alkaloids in 'Dou-chi-jiang'. The optimized chromatographic conditions were performed on an Eclipse XDB C18 column with a gradient of acetonitrile/water containing 0.1% formic acid as the mass spectrometry mobile phase and acetonitrile/water containing 0.2% diethylamine (pH 3.10, adjusted by acetic acid) as the liquid chromatography mobile phase. The fragmentation pathways by loss of CO, ·CH3 , ·NH3 , and ·NH2 CH3 were detected as characteristic for aporphine alkaloids. Based on these characteristics, total 12 analogues were identified. The quantification method was validated in terms of linearity, precision, and accuracy for six major aporphine alkaloids, which was successfully applied for simultaneous determination in ten batches of samples. The established method is simple, rapid, and specific for characterization and quantitation of aporphine alkaloids in 'Dou-chi-jiang' and other traditional Chinese medicines rich in this kind of ingredient.

Lignans from the Twigs of <em>Litsea cubeba</em> and Their Bioactivities

“…These were consistent with the substitution of the trans-cinnamyloxy at C-9, which was verified by the key HMBC correlation from H2-9 to C-9″. The positive optical rotation of 4 supported the same (8S,8′S) configuration as that of the known compound (+)-(8S,8′S)-9,9′-di-O-(E)feruloyl-secoisolariciresinol (11), which has been also isolated from this plant. 12 The (8S,8′S) configuration was confirmed by the evidence that compound 4 showed optical rotation opposite to that of (−)-1-O-feruloylsecoisolariciresinol [21].…”

“…In summary, bioassay-guided isolation of cytotoxic fractions of the twigs of L. cubeba revealed the presence of nine new lignans (1-9) and ten analogues (10)(11)(12)(13)(14)(15)(16)(17)(18)(19). Initially, all of the isolated compounds were evaluated against HCT-116, NCI-H1650, and A2780 tumor cell lines.…”

“…Cytotoxicity assay found that fraction F9 displayed potent activities against HCT-116, NCI-H1650, and A270 cell lines. Isolation of fraction F9 by Sephadex LH-20, RP-18, preparative TLC, and preparative HPLC led to the discovery of nine new lignans (1)(2)(3)(4)(5)(6)(7)(8)(9) and ten known ones (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)). Compound 1 was obtained as a white amorphous powder.…”

“…In the present study, we have investigated the constituents of the EtOAc-soluble fraction of the ethanolic extract of L. cubeba twigs. Bioassay-guided isolation of a fraction with cytotoxicity against HCT-116, NCI-H1650, and A2780 cell lines (IC50 = 28.3, 11.5, and 16.8 µ g/mL, respectively) led to the discovery of nine new lignans (1)(2)(3)(4)(5)(6)(7)(8)(9) and eleven analogues (10)(11)(12)(13)(14)(15)(16)(17)(18)(19) ( Figure 1). The structures of 1-9 were elucidated by spectroscopic methods, and their absolute configurations were determined by optical rotations and a combination of experimental and theoretically calculated electronic circular dichroism (ECD) spectra.…”

Liquid chromatographic separation of alkaloids in herbal medicines: Current status and perspectives

“…[33]. Isoquinoline alkaloids from roots and rhizomes of Litsea cubeba (Lour) Pers were separated by using ACN and buffer containing diethylamine [34].…”