Two New Spermidine Alkaloids from Chisocheton weinlandii

The investigation of the MeOH extract of the leaves of Chisocheton weinlandii Harms (Meliaceae) revealed two new open‐chain spermidine alkaloids, chisitine 1 ( 1 ) and chisitine 2 ( 2 ). Their structures were elucidated by NMR spectroscopy, tandem‐mass spectrometry, and independant syntheses (Scheme 3). Detailed MS/MS fragmentation pathways are discussed for both compounds based on H/D exchange and ¹⁸O‐labeling experiments (Schemes 1 and 2).     

Three New Hasubanan Alkaloids from Stephania hernandifolia (Willd.) Walp.

Three new hasubanan alkaloids, hernsubanines A–C ( 1 – 3 , resp.), were isolated from the whole plants of Stephania hernandifolia. Their structures were elucidated on the basis of physical and spectroscopic data. In in vitro tests for cytotoxic activity against two human cancer cell lines, A 549 and K 562, compound 1 did not exhibit any cytotoxicity.     

Steroidal alkaloids from Holarrhena antidysenterica (L.) WALL

Chemical investigations on the stem bark of Holarrhena antidysenterica resulted in the isolation of a new steroidal alkaloid designated as holadysenterine (1), together with three known steroidal alkaloids, conessine (2), isoconessimine (3) and kurchessine (4). Their structures were elucidated on the basis of 1D- and 2D-NMR techniques and high-resolution mass spectrometry.     

New Alkaloids from Aconitum vaginatum

Two new amide alkaloids, vaginatunine A and B ( 1 and 2 , resp.), and a new C₁₈‐diterpenoid alkaloid vaginatunine C ( 3 ), together with four known alkaloids, were isolated from the tubers of Aconitum vaginatum. Their structures were determined by means of spectroscopic analyses and comparison of the data with those reported previously.     

New Alkaloids from Hippeastrum papilio (Ravenna) Van Scheepen

A new phytochemical study of the indigenous Brazilian species Hippeastrum papilio is reported herein. Three novel Amaryllidaceae alkaloids were isolated, including hippapiline ( 1 ), papiline ( 2 ), and 3‐O‐demethyl‐3‐O‐(3‐hydroxybutanoyl)haemanthamine ( 3 ). Their structures were determined by physical and spectroscopic methods. In addition, the known alkaloids, haemanthamine ( 4 ), galanthamine ( 5 ), narwedine ( 6 ), 11β‐hydroxygalanthamine ( 7 ), apogalanthamine ( 8 ), and 9‐O‐demethyllycosinine B ( 9 ) were identified. The unusual cis‐B/C‐ring fusion for the new homolycorine representative hippapiline was ratified by NMR and CD spectroscopy.     

New Spermine Alkaloids from Aphelandra tetragona (VAHL) NEES

18-O-Methylchaenorpine ( 1a ) and iso-18-O-methylchaenorpine ( 1b ) two novel stereoisomeric spermine alkaloids were isolated from the roots of Aphelandra tetragona (VAHL ) NEES. Their structures were established by chemical and spectroscopic studies.     

New Diterpenoid Alkaloids from Aconitum liangshanicum

One new C₁₉‐diterpenoid alkaloid, named liangshantine ( 1 ), and three new C₂₀‐diterpenoid alkaloids, liangshansines A–C ( 2 – 4 , resp.), as well as eight known compounds, were isolated from the roots of Aconitum liangshanicum. The structures of these new alkaloids were elucidated by spectroscopic methods.     

A new triterpene and dibenzocyclooctadiene lignans from Schisandra propinqua (WALL.) BAILL

A new triterpene and two new natural dibenzocyclooctadiene lignans were isolated from the stems of Schisandra propinqua. In addition, three known lignans, octadecanoic acid, 2,3-dihydroxypropyl ester and beta-sitosterol were isolated. The structures of the new triterpene and new natural products were elucidated base on spectral analysis, including 1D and 2D NMR experiments. The isolates were tested for their cytotoxic effects against several tumor cell lines by MTT assay.     

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 Alkaloids from Incarvillea sinensis

Two new alkaloids, incarvines E ( 1 ) and F ( 2 ), were isolated from the EtOH extract of the whole plant of Incarvillea sinensis. Their structures were elucidated by spectroscopic methods, including 1D‐ and 2D‐NMR.     

New Indole Alkaloids from Rauvolfia yunnanensis

Three new indole alkaloids, 10‐methoxy‐16‐de(methoxycarbonyl)pagicerine ( 1 ), (5β)‐17‐O‐deacetyl‐5,11‐dimethoxyakuammiline ( 2 ), and ((16S,19E)‐N¹‐(hydroxymethyl)isositsirikine ( 3 ) were isolated from the roots of Rauvolfia yunnanensis, together with seven known alkaloids. The structures of the new compounds were elucidated by in‐depth spectroscopic and mass‐spectrometric analyses.     

Two New Alkaloids from Stemona tuberosa

Two new alkaloids, named tuberostemoninol A ( 1 ) and tuberostemoninol B ( 2 ), along with the known compounds tuberostemoninol ( 3 ) and bisdehydroneotuberostemonine ( 4 ), were isolated from Stemona tuberosa Lour . The structures were elucidated by means of spectroscopic analyses, including 1D‐ and 2D‐NMR experiments. The four alkaloids 1 – 4 were analyzed by on‐line high‐performance liquid chromatography/electrospray‐ionization mass spectrometry (HPLC/ESI‐MS), and their fragmentation pathways were found to be similar. Compounds 1, 2 , and 3 are isomers with the same molecular mass but which eluted at different retention times.     

New Stephaoxocane Alkaloids from Stephania longa

Three new stephaoxocane‐type alkaloids, stephalonganines A–C ( 1 – 3 ), together with the known eletefine ( 4 ), were isolated from the whole plant of Stephania longa. Their structures were fully characterized spectroscopically, and the absolute configurations of the new alkaloids were assigned by comparison of their circular‐dichroism (CD) data with those of 1,2‐dihydrostephaoxocanine ( 5 ), in combination with 2D‐NMR experiments.     

Two New Isosteroid Alkaloids from Fritillaria monatha Migo(III)

Fritillaria monatha Migo is the plant of the genus Fritillaria in the family Liliace, which mainly grows in Jiujiang in Jiangxi province. It was cultivated and utilized as an alternative for traditional Chinese medicine “Beimu” in Jiangxi1. The isolatio…     

小叶唐松草的两个新氧化阿朴芬类生物碱

Two new oxoaporphine alkaloids, 1,2,3,10-tetramethoxy-9-(2-hydroxy-4,5-dimethoxybenzyloxy)oxoaporphine (1) and 1,2,3,10-tetramethoxy-9-(4,5-dimethoxy-2-formylphenoxy)oxoaporphine (2), were isolated from Thalictrum elegans. Their structures were elucidated based on spectroscopic analysis including 1D, 2D NMR, IR and MS.     

Three New Pregnane Alkaloids from Pachysandra terminalis

Three new pregnane alkaloids, pachystermine C ( 1 ), pachysanamine A ( 2 ), and pachysanamine B ( 3 ), together with four known ones, pachystermine B ( 4 ), pachysamine A ( 5 ), (20S)‐20‐(dimethylamino)‐16α‐hydroxy‐3β‐(3′α‐isopropyl)lactam‐5α‐pregnan‐4‐one ( 6 ), and E‐salignone ( 7 ), were isolated from Pachysandra terminalis. The chemical structures of the new alkaloids were elucidated by spectroscopic methods. All the compounds were evaluated for their inhibitory activities against HL‐60, SMMC‐7721, A‐549, MCF‐7, and SW480 cell lines, some of the compounds showed stronger cytotoxicity for the test cell lines, especially compounds 2 , 3 , and 7 .     

Two New Isoquinoline Alkaloids from Carduus crispus

Two new isoquinoline alkaloids: carcrisine A and B, have been isolated from the whole plant of Carduus crispus L.. Their structures were elucidated by chemical and spectroscopic methods.