Analysis of isoquinoline alkaloids from Mahonia leschenaultia and Mahonia napaulensis roots using UHPLC-Orbitrap-MSn and UHPLC-QqQ LIT-MS/MS

Mahonia leschenaultia（ML） and Mahonia napaulensis（MN） are less known and unexplored medicinal plants of the family Berberidaceae. They are used by the Todas of Nilgiris in their religious and medical practices but chemically less identified. Hence, we decided to do extensive phytochemical analysis to explore the potential of these plant extracts. An ultrahigh performance electrospray tandem mass spectrometry（UHPLC-ESI-MS/MS）method was successfully developed for qualitative analysis of the bioactive components in Mahonia species using Orbitrap Velos Pro mass spectrometer. Sixteen compounds were identified by comparison of their retention times and mass spectra（MS） with authentic standards and reported literature. Multi-stage mass spectra（MS（2-8）） for the identification of protoberberine and aporphine alkaloids showed the sequential expulsion of all the substituents attached with their basic skeleton followed by CO loss. Eight of the identified compounds（berberine, jatrorrhizine, palmatine, magnoflorine, isocorydine, glaucine, tetrahydropalmatine and tetrahydroberberine） were simultaneously determined by another UHPLC-ESI-MS/MS method under the multiple reactions monitoring（MRM） mode quantitatively using triple quadrupole linear ion trap mass spectrometer. The analytical method was validated for 8 bioactive compounds with overall recovery in the range98.5%-103.6%（RSD≤2.2%）, precise（RSD≤2.07%） and linear（r≥0.9995） over the concentration range of 0.5-1000 ng/mL and successfully applied in ML and MN roots, which suggests the suitability of the proposed approach for the routine analysis of Mahonia species and their quality control.

Amides,Isoquinoline Alkaloids and Dipeptides from the Aerial Parts of Piper mullesua

One undescribedamide,pipermullesine A,twoundescribed isoquinoline alkaloids,pipermullesinesBand C,and six undescribed dipeptides,pipermullamides A–F,along with 28 known compounds,were isolated from the aerial parts of Piper mullesua.The structures of the undescribed compounds were elucidated based on the analysis of 1D and 2D NMR and MS data.Furthermore,the structures of pipermullesines A–Cwere confirmed by single crystal X-ray diffraction analysis.All isolates were evaluated for inhibitory activity against platelet aggregation induced by thrombin(IIa)or platelet-activating factor(PAF).(-)-Mangochinine,pellitorine,and(2E,4E)-N-isobutyl-2,4-dodecadienamide showed weak inhibitory activity against rabbit platelet aggregation induced by PAF,with IC_(50)values of 470.3μg/mL,614.9μg/mL,and 579.7μg/mL,respectively.

Alkaloid Dimers Isolated from Thalictrum baicalense Have Antitumor Activities

Comprehensive Summary A pair of heterodimeric isoquinoline alkaloid enantiomers,(+)thaliberberine A,five new thalifaberine-type aporphine-benzylisoquinoline(ABl)alkaloids,thalicultratines M-Q,and thirteen known analogues were isolated from the roots of Thalictrum baicalense Turcz.ex Ledeb.The structures were determined by extensive spectroscopic methods and ECD calculations.Thaliberberine A featuring a novel carbon skeleton coupled by two different classes of isoquinoline alkaloids,protoberberine and phthalidoisoquinoline,represents the first natural product with the berberine skeleton substituted at C-6.Plausible biosynthetic routes of 1 are proposed.

Chemical Constituents of Plants from Tribe Chelidonieae and their Bioactivities

The tribe Chelidonieae comprises 23 species of eight genera with an extensive distribution and a long medicinal usage history both in China and Western countries. A large number of chemical constituents have been isolated and identified from the species in tribe Chelidonieae, such as alkaloids, organic acids, and their derivatives, aromatics, triterpenoids, sterols, essential oils, and proteins, most of which possess a variety of bioactivities, especially for the antibacterial, anti-inflammation, antitumor, analgesia, anti-oxidation, and antiparasitic activity. Meanwhile, potential toxicities have been discovered in some constituents. Therefore, the species in tribe Chelidonieae have become a rich source for new drug discovery, biologic study, and mechanism research. This paper presents comprehensive information of the chemical constituents, pharmacological and toxicological research on the plants in tribe Chelidoieae, which is a reference for the plants in this tribe for further development.