Calyciphylline D, a novel alkaloid with an unprecedented fused-pentacyclic skeleton from Daphniphyllum calycinum

[structure: see text]. Calyciphylline D (1), a novel Daphniphyllum alkaloid with an unprecedented fused-pentacyclic skeleton containing a 8-azatricyclo[4.2.1.0.4,8]nonane ring system, has been isolated from the leaves of Daphniphyllum calycinum (Daphniphyllaceae), and the structure and relative stereochemistry were elucidated on the basis of spectroscopic data.     

Daphcalycine,a novel heptacycle fused ring system alkaloid from Daphniphyllum calycinum

A novel Daphniphyllum alkaloid, daphcalycine (1), was isolated together with known daphnicyclidin D (2) from the stem bark of Daphniphyllum calycinum. The highly condensed polycyclic structure, established by spectral analysis, possessed an unusual framework: a central quinuclidine like tricycle produced by fusion of a piperidine, a tetrahydropyran, and an oxazine ring in turn condensed to surrounding three penta-, one hexa-, and one hepta-membered rings. The relative configuration of 11 carbon stereocenters of 1 was elucidated on the basis of NOESY.     

Daphmanidin A,a novel hexacyclic alkaloid from Daphniphyllum teijsmanii

A novel alkaloid with an unprecedented fused-hexacyclic skeleton, daphmanidin A (1), and a new pentacyclic alkaloid, daphmanidin B (2), have been isolated from the leaves of Daphniphyllum teijsmanii, and the structures were elucidated on the basis of spectroscopic data. The relative and absolute stereochemistry of 1 was determined by combination of NOESY correlations and a modified Mosher method.     

Daphnicyclidins J and K, unique polycyclic alkaloids from Daphniphyllum humile

Two Daphniphyllum alkaloids with unprecedented polycyclic skeletons, daphnicyclidins J (1) and K (2), have been isolated from the stems of Daphniphyllum humile, and the structures and relative stereochemistry were elucidated on the basis of spectroscopic data. The absolute stereochemistry of 1 was established by chemical correlation with a known-related alkaloid, daphnicyclidin D (3), through a modified Polonovski reaction.     

Alkaloids from Daphniphyllum longeracemosum

A new alkaloid, daphnilongeridine ( 1 ), together with six known alkaloids, daphmacropodine ( 2 ), daphmacrine ( 3 ), codaphniphylline ( 4 ), daphniyunnine A ( 5 ), daphniyunnine C ( 6 ), and daphniyunnine E ( 7 ), were isolated from the leaves and stems of Daphniphyllum longeracemosum. The so far elusive configuration at C(25) of daphmacropodine ( 2 ) was assigned on the basis of ROESY correlations.     

Isolation, X-ray crystallography, and computational studies of calydaphninone, a new alkaloid from Daphniphyllum calycillum

[structure: see text]. A new hexacyclic alkaloid, calydaphninone (1), containing a 4-azatricyclo[5.2.2.0(1,4)]undecan ring system, has been isolated from the leaves and twigs of Daphniphyllum calycillum (Daphniphyllaceae). Its structure was elucidated by spectral and crystallographic means. Furthermore, conformations of calydaphninone (1) in solution are discussed on the basis of NMR spectral analysis and computational (B3LYP/6-31G*) results.     

Two novel alkaloids with a unique fused hexacyclic skeleton from Daphniphyllum subverticillatum

Two novel major alkaloids, deoxycalyciphylline B (1) and deoxyisocalyciphylline B (2) with a unique fused hexacyclic skeleton, together with a quite recently reported alkaloid calyciphylline B (3), were isolated from the stem of Daphniphyllum subverticillatum. Their structures were established by spectral methods and chemical evidence, especially 2D NMR techniques. The structure of 1 was further confirmed by a single-crystal X-ray diffraction determination.     

Daphniphyllum alkaloids with cytotoxic activity from Daphniphyllum angustifolium

A new Daphniphyllum alkaloid, daphnezomine W (1), together with four known ones, were isolated from the stems of Daphniphyllum angustifolium Hutch. Their structures were elucidated by spectroscopic methods and comparing with the literature data. Compound 1 was a new daphnezomine L-type alkaloid and exhibited moderate cytotoxic activity against Hela cell line with IC₅₀ of 16.0 μg/mL. A plausible biosynthetic pathway of 1 was also proposed.     

Daphnioldhamine A,a novel alkaloid from Daphniphyllum oldhami

Daphnioldhamine A, the first Daphniphyllum alkaloid with transannular effect, easily tautomerized under acidic or alkaline conditions, was isolated from the fruits of Daphniphyllum oldhami. The structure was elucidated by spectroscopic and computational approaches and chemical transformation. A plausible biosynthetic pathway of daphnioldhamine A was also proposed.     

Alkaloids from the Leaves and Stems of Daphniphyllum calycinum

One new alkaloid, named caldaphnidine H ( 1 ), together with eight known ones, daphnioldhanin G ( 2a ), methyl homosecodaphniphyllate ( 3 ), daphnezomine M ( 4 ), daphniyunine A ( 5 ), calyciphylline A ( 6 ), deoxycalyciphylline B ( 7 ), deoxyisocalyciphylline B ( 8 ), and calyciphylline B ( 9 ) was isolated from the leaves and stems of Daphniphyllum calycinum. The structure of 1 was established by spectral methods, especially 2D‐NMR techniques. The structure of daphnioldhanin G ( 2b ) reported previously was revised to 2a mainly by single‐crystal X‐ray diffraction and spectral analysis.     

Angustimine and angustifolimine: two new alkaloids from Daphniphyllum angustifolium

Two new alkaloids, angustimine (1) featuring an unprecedented skeleton, and angustifolimine (2) being a rare diamino Daphniphyllum alkaloid, were isolated from Daphniphyllum angustifolium. Their structures were elucidated by extensive spectroscopic analysis. The biosynthetic origin of 1 was postulated. Cytotoxic activities of 1 and 2 were tested, and all of them were inactive.     

Calyciphyllines A and B,two novel hexacyclic alkaloids from Daphniphyllum calycinum

[structure: see text] Two types of Daphniphyllum alkaloids with unprecedented fused-hexacyclic ring systems, calyciphyllines A (1) and B (2), have been isolated from the leaves of Daphniphyllum calycinum (Daphniphyllaceae), and the structures and relative stereochemistry were elucidated on the basis of spectroscopic data.     

Daphniglaucins A and B,novel polycyclic quaternary alkaloids from Daphniphyllum glaucescens

[structure: see text] Two cytotoxic quaternary Daphniphyllum alkaloids with an unprecedented fused-polycyclic skeleton containing a 1-azoniatetracyclo[5.2.2.0.(1,6)0.(4,9)]undecane ring system, daphniglaucins A (1) and B (2), have been isolated from the leaves of Daphniphyllum glaucescens. Their structures and relative stereochemistry were elucidated on the basis of spectroscopic data.     

Alkaloids from the Twigs and Leaves of Daphniphyllum macropodum

Three new alkaloids, macrodumines A–C ( 1 – 3 , resp.), along with ten known analogs, were isolated from the twigs and leaves of Daphniphyllum macropodum. Their structures were elucidated on the basis of spectroscopic methods. The 11‐OH configuration of the known alkaloid hydroxydaphgraciline ( 4 ) was assigned as α for the first time by comparing the NMR data with those of macrodumine C ( 3 ).     

A New Flavan-3-ol Glucoside from Daphniphyllum oldhami

A new flavan-3-ol glucoside, (-)-afzelechin-7-O-β-D-glucopyranoside (1), has been isolated from the stem of Daphniphyllum oldhami. The structure of the new compound was elucidated on the basis of detailed spectroscopie analysis and comparison with related compounds.     

Daphmanidins C and D, novel pentacyclic alkaloids from Daphniphyllum teijsmanii

[structure: see text] Two novel alkaloids with an unprecedented fused-pentacyclic skeleton, daphmanidins C (1) and D (2), have been isolated from the leaves of Daphniphyllum teijsmanii, and the structures were elucidated on the basis of spectroscopic data. The relative stereochemistry of 1 and 2 was assigned by combination of NOESY correlations and a simulation analysis. Daphmanidin C (1) elevated activity of NGF biosynthesis.     

Macropodumines D and E, two new alkaloids with unusual skeletons from Daphniphyllum macropodum Miq

[structure: see text] Two new complex polycyclic alkaloids, macropodumines D (1) and E (2), both possessing unprecedented skeletons, along with four known related alkaloids, were isolated from the leaves and barks of Daphniphyllum macropodum Miq. The structures including the relative stereochemistry of new compounds 1 and 2 were elucidated on the basis of detailed spectroscopic data analysis.     

交让木树皮中的新虎皮楠生物碱的结构研究

本文报道从虎皮楠科植物交让木的树皮中分到4个新的和7个已知的虎皮楠生物碱的结构研究。4个新生物碱分别命名为脱氧交让木碱（dehydroxymacropodumineA）(1), 4,21-脱乙酰-23-脱甲基-脱氧交让木胺（4,21-deacetyl-23-demethyl-deoxyyuzurimine） (2),7-氧杂--脱氧交让木胺（7-oxo-deoxyyuzurimine）(3),和4-乙酰氧-虎皮楠素B （4-acetoxydaphmanidinB）(4)。新化合物1-4的结构是通过仔细解析其波谱数据和与已知结构相关的化合物波谱数据比较而确定。脱氧交让木碱（dehydroxymacropodumineA）(1) 具有罕见的11元环的大环内酯结构,是从自然界中分到的第二个具有这一新颖结构特征的生物碱。     

Daphnicyclidins A-H, novel hexa- or pentacyclic alkaloids from two species of Daphniphyllum.

Eight highly modified Daphniphyllum alkaloids with unprecedented fused hexa- or pentacyclic skeletons, daphnicyclidins A-H (1-8), have been isolated from the stems of Daphniphyllum humile and D.teijsmanni, and their structures were elucidated on the basis of spectroscopic data and chemical means. The stereochemistry was elucidated by combination of NOESY correlations, X-ray crystallographic data, and CD analyses.     

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.