Two Novel Alkaloids from Zanthoxylum nitidum

Two novel alkaloids, 4,5‐dihydroxy‐1‐methyl‐3‐oxo‐2‐(trichloromethyl)‐3H‐indolium chloride ( 1 ) and 4‐(2‐methoxyethyl)‐N,N‐dimethylbenzenamine ( 2 ), were isolated from the EtOH extract of the roots of Zanthoxylum nitidum. Their structures were identified on the basis of spectroscopic and mass‐spectrometric analyses.     

New alkylamide from the stems of Zanthoxylum nitidum

A new alkylamide, named (2E,6E,8E)-N-(2-methylpropyl)-10-oxo-2,6,8-decatrienamide (1), together with 22 known compounds (2–23), were isolated from the stems of Zanthoxylum nitidum. Their structures were elucidated by spectroscopic methods, including 1D and 2D NMR spectroscopy. The isolated compounds exhibited slightly antioxidant activities through DPPH and ABTS radical scavenging assays but showed no antibacterial activity against Streptococcus mutans ATCC2517, a dental caries causing bacteria.     

Two New Steroidal Alkaloids from Veratrum nigrum L.

Phytochemical studies on Veratrum nigrum L., collected in Shanxi, P. R. China, resulted in the isolation of two new steroidal alkaloids, 23‐methoxycyclopamine ( 1 ) and 15‐O‐(2‐methylbutanoyl)‐3‐O‐veratroylprotoverine ( 2 ). The structures of the two new compounds were established by means of extensive NMR spectroscopic studies.     

Two New Alkaloids from Flueggea virosa

Two new securinega‐type alkaloids and four known ones were isolated from the twigs and leaves of Flueggea virosa. The structures of the new compounds were elucidated by means of spectroscopic methods (UV, IR, HR‐ESI‐MS, and 1D‐ and 2D‐NMR), and the absolute configurations were assigned by CD spectra. The structures of the known compounds were identified by comparison of their physical and spectroscopic data with those reported in the literature.     

Two New Daphniphyllum Alkaloids from Daphniphyllum calycinum

Two new daphniphyllum alkaloids named 2‐hydroxyyunnandaphnine D ( 1 ) and methyl 7‐hydroxyhomodaphniphyllate ( 2 ), together with eight known alkaloids, daphnioldhanin D, calyciphylline F, calyciphylline B, deoxycalyciphylline B, daphnicyclidin H, macropodumine C, 9,10‐epoxycalycine A, and yunnandaphnine A, were isolated from the stems and leaves of Daphniphyllum calycinum. Their structures and relative configurations were established on the basis of spectral evidence (including 2D‐NMR) and subsequently confirmed by a single‐crystal X‐ray crystallographic diffraction analysis.     

Electrochemistry of Benzophenanthridine Alkaloids. Formation and Characterization of Redox Active Films from Products of Sanguinarine and Chelerythrine Oxidation

The behavior of sanguinarine and chelerythrine alkaloids upon electrochemical oxidation on solid electrodes in buffered aqueous medium is reported in this study. Electro‐oxidation of sanguinarine and chelerythrine results in the formation of redox active electropolymerized films. The films were characterized by cyclic voltammetry, EQCM and surface enhanced Raman scattering spectroscopy excited in near‐infrared range. The electropolymerization is suggested to proceed via formation of alkaloids' ortho‐benzoquinone derivatives.     

Bishordeninyl Terpene Alkaloids from Zanthoxylum Integrifoliolum

Examination of the leaves of Zanthoxylum integrifoliolum led to the isolation of a new bishordeninyl alkaloid, integramine, along with alfileramine, α‐allocryptopine, pseudoprotopine and (+)‐sesamin from the tertiary non‐phenolic base fraction. The structures of these compounds were elucidated by spectral evidence.     

Two New Indole Alkaloids from Emmenopterys henryi

Two new indole alkaloids, 5‐oxodolichantoside ( 1 ) and deglycocadambine ( 2 ), were isolated from the twigs and leaves of Emmenopterys henryi, together with four known indole alkaloids and five known iridoids. The structures of the new compounds were elucidated on the basis of extensive spectroscopic analyses, including 1D‐ and 2D‐NMR experiments, and confirmed by single‐crystal X‐ray diffraction studies. This is the first report on the isolation of indole alkaloids from this species. The indole alkaloids were evaluated for their cytotoxic activities against five human cancer lines.     

Two New Nitrone Alkaloids from Huperzia serrata

Two new nitrone alkaloids were isolated from the whole plant of Huperzia serrata (Thunb .) Trev . They are both phlegmarine‐type lycopodium alkaloids with a nitrone moiety. Their structures were elucidated on the basis of spectral evidences, and their configurations were established on the basis of optical rotation, CD, and NOESY‐NMR data.     

Two New Lycodine Alkaloids from Lycopodiastrum casuarinoides

Two new lycodine alkaloids, 11β‐methoxyhuperzine B ( 1 ) and 16‐oxohuperzinine ( 2 ), together with seven known ones, huperzinine N‐oxide, huperzine D, casuarinine A, huperzine B, casuarinine B, huperzinine, and N‐methyllycodine, were isolated from whole plants of Lycopodiastrum casuarinoides. Their structures were elucidated by spectroscopic methods, including NMR and MS experiments.     

Cytotoxicity of benzophenanthridine alkaloids from the roots of Zanthoxylum nitidum (Roxb.) DC. var. fastuosum How ex Huang

This work aimed to investigate benzophenanthridine from the roots of Zanthoxylum nitidum (Roxb.) DC. var. fastuosum How ex Huang for the first time. Thirteen benzophenanthridines were isolated, and our results of the cytotoxic activities indicated that compound 6 exhibited the best potency against A549, Hela, SMMC-7721 and EJ, with the IC₅₀ values of 27.50, 37.50, 16.95 and 60.42 μM, respectively. Compounds 7 and 11 also showed strong cytotoxicity when tested against the four human cancer cell lines (A549, Hela, SMMC-7721 and EJ), while only compounds 12 and 13 displayed cytotoxicity in inhibiting BALL-1 proliferation among all the compounds. These results suggested that benzophenanthridines may become a valid alternative of potential basis for new anti-proliferative agents.     

Two New Indole Alkaloids from Tabernaemontana hystrix Steud. (Apocynaceae)

Two new monoterpene indole alkaloids named ibogamine‐7,8‐dione ( 1 ) and 12‐methoxyvoachalotine ( 2 ), and eight known ones, coronaridine ( 3 ), coronaridine hydroxyindolenine ( 4 ), 5‐oxocoronaridine ( 5 ), 3‐oxocoronaridine hydroxyindolenine ( 6 ), 3‐oxocoronaridine ( 7 ), vobasine ( 8 ), ibogamine ( 9 ), and olivacine ( 10 ), were isolated from a CH₂Cl₂ extract of the root bark from Tabernaemontana hystrix. The structures of the compounds were elucidated on the basis of spectroscopic data analyses, mainly ¹H‐ and ¹³C‐NMR, including 2D experiments (¹H,¹H‐COSY, HMBC, and HMQC).     

Formation of Human Telomeric G-quadruplex Structures Induced by the Quaternary Benzophenanthridine Alkaloids:Sanguinarine,Nitidine,and Chelerythrine

The ligands which can facilitate the formation and stabilize G‐quadruplex structures have attracted enormous attention due to their potential ability of inhibiting the telomerase activity and halting tumor cell proliferation. It is noteworthy that the abilities of the quaternary benzophenanthridine alkaloids (QBAs), the very important G‐quadruplex binders, in inducing the formation of human telomeric DNA G‐quadruplex structures, have not been reported. Herein, the interaction between single‐strand human telomeric DNA and three QBAs: Sanguinarine (San), Nitidine (Nit) and Chelerythrine (Che), has been investigated. Although these molecules are very similar in structure, they exhibit significantly different abilities in inducing oligonucleotide d(TTAGGG)₄ (HT4) to specific G‐quadruplex structures. Our experimental results indicated that the best ligand San could convert HT4 into antiparallel G‐quadruplex structure completely, followed by Nit, which could transform to mixed‐type or hybrid G‐quadruplex structure partially, whereas Che could only transform to antiparallel G‐quadruplex structure in small quantities. The relative QBAs' inducing abilities as indicated by the CD data are in the order of San>Nit>Che. Further investigation revealed that the G‐quadruplex structures from HT4 induced by QBAs are of intramolecular motif. And only sequences with certain length could be induced by QBAs because of their positive charges which could not attract short chain DNA molecules to close to each other and form intermolecular G‐quadruplex. In addition, the factors that affect the interaction between HT4 and QBAs were discussed. It is proposed that the thickness of the molecular frame and the steric hindrance are the primary reasons why the subtle differences in QBAs' structure lead to their remarkable differences in inducing the formation of the G‐quadruplex structures.     

Two New Lycopodium Alkaloids from Lycopodium obscurum

Two new Lycopodium alkaloids, (+)‐cermizine D N‐oxide ( 1 ) and (8β)‐8‐(acetyloxy)obscurumine A ( 2 ), along with five known compounds, were isolated from the crude alkaloid portion of Lycopodium obscurum. Their structures were elucidated on the basis of spectroscopic data and chemical correlation. All of these alkaloids were tested in an assay for acetylcholine esterase (AChE) inhibitory activity.     

Three New C19‐Diterpenoid Alkaloids from Aconitum forrestii

A further study of the alkaloid constituents of Aconitum forrestii led to the isolation of three new C₁₉‐diterpenoid alkaloids, named 14‐acetoxy‐8‐O‐methylsachaconitine ( 1 ), 14‐acetoxyscaconine ( 2 ), and 8‐O‐ethylcammaconine ( 3 ). Their structures were determined by UV, IR, and MS, 1D‐ and 2D‐NMR analyses.     

Two New C20‐Diterpenoid Alkaloids from Aconitum carmichaelii

Two new C₂₀‐diterpenoid alkaloids, named aconicarchamines A and B ( 1 and 2 , resp.), were isolated from Aconitum carmichaelii. By UV, IR, MS, and 1D‐ and 2D‐NMR analyses, their structures were elucidated as 14,17‐dihydro‐14,17‐dihydroxyajabicine and 15‐O‐acetyllassiocarpine. Compound 1 is the third C₂₀‐diterpenoid alkaloid with the lycoctine skeleton bearing an exocyclic C‐atom at C(14).     

Two New Lycopodine Alkaloids from Huperzia serrata

Two new lycopodine alkaloids, (12β)‐12‐hydroxyhuperzine G ( 1 ) and (5β,6β,15α)‐15‐methyllycopodane‐5,6‐diol ( 2 ), were isolated from the whole plants of Huperzia serrata, together with six known compounds, huperzines A, B, and G, phlegmariurine B, (8β)‐8‐hydroxyphlegmariurine B, and lycoposerramine D. Their structures were elucidated on the basis of spectroscopic analysis, including HR‐ESI‐MS, ¹H‐ and ¹³C‐NMR, DEPT, ¹H,¹H‐COSY, HSQC, HMBC, and NOESY data.     

Two New Alkaloids from the Roots of Aconitum sinomontanum Nakai

Two new alkaloids, ranaconidine (=20‐ethyl‐1α,14α,16β‐trimethoxyaconitane‐4,7,8,10‐tetrol; 1 ) and N‐(chloromethyl)taspine (=1‐[2‐(N‐(chloromethyl)‐N,N‐dimethylaminium)ethyl]‐3,8‐dimethoxybenzopyrano[5,4,3‐cde]benzopyran‐5,10‐dione; 2 ), together with two known compounds, i.e., benzethonium chloride ( 3 ) and ranaconine ( 4 ) were isolated from the roots of Aconitum sinomontanum Nakai . The structures of the compounds were elucidated on the basis of spectral evidences and in the comparison with previously published data.     

Two New Indole Alkaloids from the Bark of Anthocephalus chinensis

Two new indole alkaloids, cadambinic acid ( 1 ) and isonauclefidine ( 2 ), were isolated from the bark of Anthocephalus chinensis. The structures were identified by spectroscopic methods, and the compounds were tested for their biological activities. Both compounds showed weak cytotoxicities against A549, BGC‐823, and HeLa cells in biological assays.