Two New Norditerpenoid Alkaloids of Aconitum nagarum

Aconitum nagarum Stapf is mainly distributed in Yunnan province of China. Its roots can release pain and dispel dampness. They have been used as a folk medicine in China for the treatment of cold limbs in syncope, epigastric pain, vomiting and diarrhea1. The chemical constituents of this plant have been investigated1-4. For the further investigation, two new norditerpenoid alkaloids 13-hydroxyfranchetine 1 and 10- dehydroxyflavaconitine 2 were isolated from the ethanol extract of the roots o…     

Oxidation of the Norditerpenoid Alkaloids Isotalatizidine and 6-Epiforsticine

Oxidation of 1 with KMnO4 in acetone-H2O (1:1) for 1h gave nevadenine 2 (38%). But, 3 was formed in 98% yield when prolonging time and raising temperature (40℃). Reaction of 1 and 10 with Conforth reagent afforded the ketones 11 (55%), 12 (30%), and 13 (13%), 14 (20%), respectively. While oxidation of 7 and 15 with a variety of the oxidizing agents gave 17 only in low 20% of yield besides the minor 16. In addition, 1 was converted to 2 by the fungi Curvularia lunata.     

Oxidation of the Norditerpenoid Alkaloids Isotalatisidine and 6-Epiforsticine

Inpreviousworksonmodificationsofnorditerpenoidalkaloids,wereportedsomeimportantreactionssuchasN-deethylationandpreparationsoftheimmesand7,17-secoderivatives'.NowwewishtorepoFtoxidationofthenorditerpenoidalkaloidsisotalatizidineand6-epiforsticine.Oxidationofnorditerpenoidalkalnidshavinganla-hydroxylgroupwithreagentssuchasKMnO.K,Fe(CN),,OsO.,Ag,OandNBSaffordedcompoundswithanO,Nmixedacetalsystems=.Thus,treatmentofisqtalatizidineIwithKMnO.inacetone-H,O(5;1)forIhgavetheknowncompoundnevade…     

草乌中二萜类生物碱的电喷雾串联质谱研究

利用电喷雾质谱技术对传统中药草乌中的二萜类生物碱进行直接分析鉴定.通过实验数据并对比文献发现,草乌中含有单酯型、双酯型、三酯型和脂类等共4种类型生物碱,其中三酯型和脂类生物碱在草乌中为首次发现.由于这些生物碱的结构相似,在电喷雾串联质谱中碎裂方式相同,因此根据电喷雾串联质谱结果确定了这些生物碱的结构.     

Analysis of Norditerpenoid Alkaloids. Extracted from Aconitum sinomantanum Nakai by Electrospray Ionization Tandem Mass Spectrometry

Introduction AconitumsinomantanumNakai(GaowutouinChi nese)isdistributedinthenorthwesternareaofChina,anditsroots(RAS)areexternallyusedasakindof folkmedicineinChina.Themainactiveconstituentsof RASarenorditerpenoidalkaloids.Themajoralkaloid,lappaconitine,was…     

The Revised Structure of the Norditerpenoid Alkaloid Peregrine

The structure of peregrine ( 1 ), a norditerpenoid alkaloid isolated from Delphinium peregrinum var. elongatum BOISS ., was revised on the basis of the ¹H-COSY, HMQC, HMBC, and ROESY NMR spectra and of the X-ray analysis of its parent alcohol 2 . Some of the ¹³C-NMR resonances of 1 and the related alkaloids peregrine alcohol ( 2 ), 14-O-acetylperegrine ( 3 ), bicoloridine ( 4 ), bicoloridine alcohol ( 5 ), 6-O-acetylbicolorine ( 6 ), bicolorine ( 7 ), and 14-O-acetylbicolorine ( 8 ), were also reassigned.     

Norditerpenoid alkaloids from Aconitum karakolicum Rapaics

Two new norditerpenoid alkaloids, acofamine A (1) and acofamine B (2) were isolated from the aerial parts of Aconitum karakolicum Rapaics. The structures of these compounds were established by spectroscopic methods.     

Two New Norditerpenoid Alkaloids from Delphinium Souliei

DelphiniumsoulieiFranch,distributedintheSouthwestofGansuProvince,WestofSichuanProvince,andtheQinghaiProvinceofChina,isreportedtopossessantipyretic,antitoxic,antidysenteric,andantidiarrhealactivities.linthisstUdy,twonewditerpenoidalkaloidswereisolatedfromthewholeplantsofD.soulidi.TheirstructUreswereestablishedassoulineA(l)andsoulineB(2)onthebasisofspectraldata.SoulineA(l)wasisolatedascolorlesscrystals.Themolecularionpeakatm/z477.2678initsHREIMSrevealedthemolecularformulaC26H39NO7(cafe…     

Two New Norditerpenoid Alkaloids from Aconitum spicatum Stapf

Two new norditerpenoid alkaloids, spicatine A (1) and spicatine B (2) were isolated from the root of Aconitum spicatum. The new compounds were deduced on the basis of their spectral data (IR, HREIMS, EIMS, 1D, 2D-NMR). This is the first whole report on the isolation of diterpenoid alkaloids from the A.spicatum Stapf.     

Norditerpenoid Alkaloids from the Aerial Parts of Aconitum cochleare Woroschin

From the aerial parts of Aconitum cochleare Woroschin, two new norditerpenoid alkaloids named aconitilearine ( 1 ) and N‐deethylmethyllycaconitine ( 2 ) were isolated along with the eight known norditerpenoid alkaloids 3 – 10 . The structures for the new compounds were established on the basis of ¹H, ¹³C, DEPT, homonuclear ¹H,¹H‐COSY, NOESY, HSQC, and HMBC NMR studies.     

Norditerpenoid alkaloids from the processed tubers of Aconitum carmichaeli

Four new and five known norditerpenoid alkaloids were isolated from the processed tubers of Aconitum carmichaeli. The new alkaloids are 14-O-cinnamoylneoline (3), 14-O-anisoylneoline (4) 14-O-veratroylneoline (5), and lipo-14-O-anisoylbikhaconine (8). The known alkaloids are neoline (1), 14-O-acetylneoline (2), foresaconitine (6), crassicauline A (7), and lipohypaconitine (9). Alkaloids 2, 6, and 7 were isolated from this plant for the first time. The structures of the new alkaloids were established by spectroscopic and chemical methods.     

Macrorhynines A and B,Two Novel Norditerpenoid Alkaloids from Aconitum macrorhynchum

Two novel norditerpenoid alkaloids, macrorhynines A and B ( 1 and 2 ), together with seven known compounds, were isolated from Aconitum macrorhynchum. The structures of the new compounds were elucidated as (1α,6α,14α)‐8‐acetoxy‐1,6,16‐trimethoxy‐4‐(methoxymethyl)aconitan‐14‐yl 4‐methoxybenzoate ( 1 ) and (1α,6α,14α)‐8‐acetoxy‐13‐hydroxy‐1,6,16‐trimethoxy‐4‐(methoxymethyl)aconitan‐14‐yl 4‐methoxybenzoate ( 2 ) on the basis of spectral analyses. The novel compounds were found to contain the rare C(19)?N, azomethine, group.     

Norditerpenoid Alkaloids from the Roots of Aconitum hemsleyanum Pritz.var.Pengzhouense

In continuation of our studies on Aconitum hemsleyanum Pritz.var. pengzhouense, two new norditerpenoid alkaloids, pengshenines A(1) and B(2),have isolated from the roots of the plants and their strucures were elucidated by 1D-and 2D-NMR.     

Phormidinines A and B, novel 2-alkylpyridine alkaloids from the cyanobacterium Phormidium sp.

Novel 2-alkylpyridine alkaloids, phormidinines A (1) and B (2), were isolated from cyanobacterium Phormidium sp. Their structures were determined by spectroscopic analysis. The absolute stereochemistry of 1 was established by the modified Mosher’s method.     

Habaenines A and B,Two New Norditerpenoid Alkaloids from Aconitum habaense

Two new norditerpenoid alkaloids, habaenine A and B ( 1 and 2 ), together with two known compounds, were isolated from Aconitum habaense. The structures of the new compounds were elucidated on the basis of spectral analyses as (1α,6α,16β)‐8‐(acetyloxy)‐20‐ethyl‐13‐hydroxy‐1,6,16‐trimethoxy‐4‐(methoxymethyl)‐19‐oxoaconitan‐14‐yl 4‐methoxybenzoate ( 1 ) and (1α,6α,16β)‐8‐(acetyloxy)‐13‐hydroxy‐1,6,16‐trimethoxy‐4‐(methoxymethyl)‐aconitan‐14‐yl 4‐methoxybenzoate ( 2 ).     

A Concise Synthesis of (－)-Indolizidines 209D and 209B

A general stereoselective synthetic route to 5-substituted and 5,8-disubstituted indolizidine alkaloids has been developed starting from commercially available L-proline. (－)-Indolizidines 209D and 209B were efficiently synthesized in 9.8% and 14.8% overall yields in seven and five-step reactions from readily available aldehyde 3 and ketone 10, respectively. The key steps of this synthesis involve a substrate-induced asymmetric addition of ethyl lithiopropiolate to aldehyde 3 or methyl ketone 10, and a two-step one-pot hydrogenation/cyclization sequence to construct the bicyclic skeleton.