Alkaloids from Fritillaria Hupehensis

Phytochemical investigation of the bulbs of Fritillaria hupehensis resulted in the isolation and structural elucidation of a new highly conjugated alkaloid of veratramine type identified as 3β,23β-dihydroxy-7,12（14）-dien-5α- veratramin-6-one （1）, together with two known alkaloids, ebeinine （2） and zhebeinine （3）, which were isolated for the first time from F. hupehensis. The structures of alkaloids 1-3 were established by extensive 1D and 2D NMR spectral analyses.     

Isolation and chemotaxonomic significance of stenine- and stemoninine-type alkaloids from the roots of Stemona tuberosa

One new stenine-type alkaloid,tuberostemonine D(1),together with five known stenine-type alkaloids(2–6) and two known stemoninine-type alkaloids(7 and 8),were isolated from the roots of Stemona tuberosa.Their structures were elucidated by extensive spectroscopic methods(IR,UV,MS,1D and 2D NMR),and the structure of 1 was further confirmed by X-ray diffraction analysis.First simultaneous isolation of stenine- and stemoninine-type alkaloids not only added a new chemical type and increased the chemical diversity of Stemona tuberosa,but also provided chemotaxonomic clues for the close relationship between genera Stemona and Stichoneuron,and favored retaining them in the same family.     

Three new sesquiterpene alkaloids from the root of Tripterygium wilfordii

<正>Three new sesquiterpene alkaloids,1-desacetylwilforgine(1),1-desacetylwilforine(2),and 9′-hydroxy-2-nicotinoylwilforine (3) were isolated from the roots of Tripterygium wilfordii Hook f.,along with six known alkaloids.Their structures were established on the basis of spectral analysis.     

Two New C19-Diterpenoid Alkaloids from Delphinium davidii Franch.

Two new C19-diterpenoid alkaloids, davidisines A (1) and B (2) along with thirteen known alkaloids were isolated from the whole herb of Delphinium davidii Franch. Their structures were established by spectral methods, especially 2D NMR techniques.     

Cytotoxic Diarylheptanoids from Pericarps of Juglans Cathayensis Dode

A novel diarylheptanoid, named Jugcathanin（1）, along with two known diarylheptanoids（2,3）, were isolated from the fresh pericarps ofduglans Cathayensis Dode. A known triterpene（4） and a known aphthaoquinone（5） were also isolated from the plant. Their structures were elucidated on the basis of spectroscopic studies. All the compounds exhibited moderate cytotoxicities against human Hela, HepG2, and HL-60 cell lines.     

中药枸骨叶中三萜皂苷和黄酮苷类成分研究

A new triterpene glycoside, pomolic acid 3-O-6″-methyl-β-D-glucuronopyranosyl-（1→3）-α-L-arabino- pyranoside, and a new flavonol glycoside, quercetin 3-O-β-D-glucopyranosyl-（1→2）-α-L-arabinopyranoside together with three known triterpene saponins and two flavonol glycosides, were isolated from the leaves of Ilex cornuta. Their structures were established on the basis of spectroscopic analysis.     

Steroidal alkaloids from the bulbs of Fritillaria monatha

Two new Steroidal alkaloids, named pengbeisine A and pengbeisine B, were isolated from the fresh bulbs of Fritillaria monatha Migo. along with a known alkaloid. The structures were characterized as 22,26-imino-17, 23-oxido-5α-jerv-6-oxo-2α,3β-diol and 22, 26-imino-17, 23-oxido-5α-jerv-6-oxo-2β,3α-diol on the basis of spectroscopic methods.     

南中国海柳珊瑚网状软柳珊瑚Subergorgia reticulata中的多氧化甾醇

Two new polyoxygenated steroids, reticulatic acid （1） and reticulatin （2）, together with a known compound 3,22,25-trihydroxy-16-24,20-24-bisepoxy-3β,16β,20S,22R,24S-cholest-5-ene （3）, were isolated from the CH2Cl2/ EtOH extract of the South China Sea gorgonian coral Subergorgia reticulata. Their structures were established on the basis of extensive spectroscopic analysis. The absolute stereochemistry of compounds 2 and 3 was determined by the X-ray crystallographic analysis and the Mosher ester determination.     

New flavan and unusual chalcone glycosides from Drypetes parvifolia

Two new compounds 7-hydroxy-5-O-（β-D-glucopyranoside） flavan （1） and （Z）-4＇,6＇-dihydroxy-2＇-O-（β-D-glucopyranoside） chalcone （2）, along with eight known compounds, were isolated from the stem bark of Drypetes parvifolia （Euphorbiaceae）. Their structures were established on the basis of spectroscopic analysis and chemical evidence.     

New C19－Diterpenoid Alkaloids from the Roots of Delphinium Giraldii

Three new C19-diterpenoid alkaloids, giraldines A (1), B (3) and C (4), were isolated from the roots of Delphinium giraldii Diels, together with three known C19-diterpenoid alkaloids, dihydrogadesine (5), tatsiensine (6) and siwanine A (7), as well as their structures were elucidated by chemical evidence and spectral analyses, including IR, MS, 1D NMR and 2D NMR.     

Optical Resolution and Structure Determination of New Indolizidine Alkaloids from Elaeocarpus sphaericus

Two new indolizidine alkaloids, (±)‐3‐oxoisoelaeocarpine ( 1 ) and (±)‐elaeocarpine N‐oxide ( 2 ), along with three known alkaloids, (±)‐isoelaeocarpine ( 3 ), (±)‐elaeocarpine ( 4 ), and (?)‐isoelaeocarpiline ( 5 ), were isolated from an EtOH extract of the branches and leaves of Elaeocarpus sphaericus. The structures of these compounds were determined by spectroscopic and chemical methods. Furthermore, enantiomers of compounds 1 and 3 were separated on a chiral CD‐Ph column, and their absolute configurations were determined by TD‐DFT (=time‐dependent density‐functional theory) quantum‐chemical calculations of their electronic circular dichroism (ECD) spectra.     

Henrycinols A and B,Two Novel Indole Alkaloids Isolated from Melodinus henryi Craib

Henrycinols A ( 1 ) and B ( 2 ), two novel indole alkaloids, together with three known compounds, (+)‐Δ¹⁴‐vincamine ( 3 ), (+)‐16‐epi‐Δ¹⁴‐vincamine ( 4 ), and (+)‐isoeburnamine ( 5 ), were isolated from the roots of Melodinus henryi Craib . Their structures were established on the basis of 1D‐ and 2D‐NMR spectroscopic analysis. The relative configuration of henrycinols A and B was determined by NOESY analysis.     

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.     

Biflavonoids,Lignans, and Related Compounds from the Roots of Diplomorpha canescens

Two new biflavonoids, 14″‐O‐methyldihydrodaphnodorin B ( 1 ) and 14″‐O‐methyldaphnodorin J ( 2 ), along with 16 known compounds, i.e., dihydrodaphnodorin B ( 3 ), daphnodorin J ( 4 ), 3″‐epidihydrodaphnodorin B ( 5 ), daphnodorin B ( 6 ), neochamaejasmin B ( 7 ), sikokianin B ( 8 ), (?)‐syringaresinol ( 9 ), (?)‐syringaresinol 4‐O‐β‐D ‐glucopyranoside ( 10 ), (+)‐nortrachelogenin ( 11 ), (?)‐lariciresinol ( 12 ), (?)‐pinoresinol ( 13 ), syringin ( 14 ), syringinoside ( 15 ), daphnoretin ( 16 ), phorbol 13‐acetate ( 17 ), and methyl paraben ( 18 ) were isolated from the roots of Diplomorpha canescens (Meisn.) C.A. Meyer . The structures were determined on the basis of spectroscopic data.     

Über Alkaloide aus Laurelia novae-zelandiae A. CUNN. 5. Mitteilung über natürliche und synthetische Isochinolinderivate

From an extract of Laurelia novae-zelandiae A. CUNN . the aporphine alkaloids (?)-pukateine (I), (?)-pukateine methyl ether (II), (?)-roemerine (IV), (?)-mecambroline (V), (+)-boldine (VII), (+)-isoboldine (VIII), (+)-laurolitsine (IX), and the proaporphine alkaloid (+)-stepharine (X) were isolated. Compounds II and V were up to now not described as natural alkaloids. These and the alkaloids IV, VII, VIII, IX and X are new for L. novae-zelandiae.     

Three New Indole Alkaloids from the Leaves of Kopsia officinalis

Three new indole alkaloids, 11,12‐de(methylenedioxy)danuphylline ( 1 ), methyl (2β,11β,12β,19α)‐6,7‐didehydro‐8,21‐dioxo‐11,21‐cycloaspidospermidine‐2‐carboxylate ( 2 ), and (2β,5β)‐aspidofractinin‐16‐ol ( 3 ) were isolated from Kopsia officinalis, together with 16 known compounds. Their structures were determined by spectroscopic methods. The isolated known compound (?)‐12‐methoxykopsinaline displayed antimanic effects in Drosophila, with an IC₅₀ value of 12.5 μg/ml.     

Amaryllidaceae Alkaloids from Lycoris radiata

A phytochemical investigation on bulbs of Lycoris radiata resulted in the isolation of three new Amaryllidaceae alkaloids, named 5,6‐dehydrodihydrolycorine ( 1 ), 6β‐acetoxycrinamine ( 2 ), and (+)‐8‐O‐acetylhomolycorine α‐N‐oxide ( 3 ), together with eleven known alkaloids, 4 – 14 . The structures of the new alkaloids were established by means of spectroscopic methods, and the known compounds were identified by comparison of their data with those in the literature. Compound 2 showed cytotoxicity against HL‐60, A‐549, and MCF‐7 cells, with IC₅₀ values of 8.1, 24.3, and 15.0 μM , respectively.     

Total Syntheses and Biological Evaluation of Both Enantiomers of Several Hydroxylated Dimeric Nuphar Alkaloids

Herein, we describe the first total syntheses of five members of the dimeric nuphar alkaloids: (+)‐6,6′‐dihydroxythiobinupharidine (+)‐ 1 a , (+)‐6‐hydroxythiobinupharidine (+)‐ 1 b , (?)‐6,6′‐dihydroxythionuphlutine (?)‐ 2 a , (?)‐6,6′‐dihydroxyneothiobinupharidine (?)‐ 3 a , and (+)‐6,6′‐dihydroxyneothionuphlutine (+)‐ 4 a . The latter two have not been found in nature. We have also made each of their enantiomers (?)‐ 1 a – b , (+)‐ 2 a , (+)‐ 3 a , and (?)‐ 4 a . The key step in these syntheses was the dimerization of an α‐aminonitrile (a hydrolytically stable surrogate for its corresponding hemiaminal) with chiral Lewis acid complexes. We have also reassigned the literature structures of (+)‐ 1 a – 1 b —for those instances in which the NMR spectra were obtained in CD₃OD—to their corresponding CD₃O‐adducts. Our efforts provide for the first time apoptosis data for (?)‐ 3 a , (+)‐ 4 a , and all five non‐natural enantiomers prepared. The data indicate high apoptotic activity regardless of the enantiomer or relative stereochemical configuration at C7 and C7′.     

Alkaloids from Bulbocodium vernum L. Content material of Liliaceae-Wurmbaeoidaea

From whole plants of Bulbocodium vernum L. the flavone luteoline (I) and the alkaloids colchicine (II), N-formyl-N-deacetylcolchicine (III), 3-demethylcolchicine (V), (+)-bulbocodine (IX) and (?)-kreysigine (XI) were isolated in crystals. The presence of 2-demethylcolchicine (IV), ß- (VII) and γ-lumicolchicine (VIII), demecolcine (VI) and five not identified alkaloids was demonstrated by thin-layer chromatography. On the basis of ultraviolet, infrared and mass spectra, PMR.-analysis (Overhauser effect), and circular dichroism, the (6a-R, 8a-S)homo-proaporphine structure IX, with one methoxy group at C-2, has been assigned to (+)-bulbocodine. The (6a-R)-structure (XI) was deduced for (?)-kreysigine by comparing its optical rotation and circular dichroism which the values of (?)-multifloramine (X), the structure of which is known.     

Analogues of α‐Campholenal (= (1R)‐2,2,3‐Trimethylcyclopent‐3‐ene‐1‐acetaldehyde) as Building Blocks for (+)‐β‐Necrodol (= (1S,3S)‐2,2,3‐Trimethyl‐4‐methylenecyclopentanemethanol) and Sandalwood‐like Alcohols

To complete our panorama in structure–activity relationships (SARs) of sandalwood‐like alcohols derived from analogues of α‐campholenal (= (1R)‐2,2,3‐trimethylcyclopent‐3‐ene‐1‐acetaldehyde), we isomerized the epoxy‐isopropyl‐apopinene (?)‐ 2d to the corresponding unreported α‐campholenal analogue (+)‐ 4d (Scheme 1). Derived from the known 3‐demethyl‐α‐campholenal (+)‐ 4a , we prepared the saturated analogue (+)‐ 5a by hydrogenation, while the heterocyclic aldehyde (+)‐ 5b was obtained via a Bayer‐Villiger reaction from the known methyl ketone (+)‐ 6 . Oxidative hydroboration of the known α‐campholenal acetal (?)‐ 8b allowed, after subsequent oxidation of alcohol (+)‐ 9b to ketone (+)‐ 10 , and appropriate alkyl Grignard reaction, access to the 3,4‐disubstituted analogues (+)‐ 4f,g following dehydration and deprotection. (Scheme 2). Epoxidation of either (+)‐ 4b or its methyl ketone (+)‐ 4h , afforded stereoselectively the trans‐epoxy derivatives 11a,b , while the minor cis‐stereoisomer (+)‐ 12a was isolated by chromatography (trans/cis of the epoxy moiety relative to the C₂ or C₃ side chain). Alternatively, the corresponding trans‐epoxy alcohol or acetate 13a,b was obtained either by reduction/esterification from trans‐epoxy aldehyde (+)‐ 11a or by stereoselective epoxidation of the α‐campholenol (+)‐ 15a or of its acetate (?)‐ 15b , respectively. Their cis‐analogues were prepared starting from (+)‐ 12a . Either (+)‐ 4h or (?)‐ 11b , was submitted to a Bayer‐Villiger oxidation to afford acetate (?)‐ 16a . Since isomerizations of (?)‐ 16 lead preferentially to β‐campholene isomers, we followed a known procedure for the isomerization of (?)‐epoxyverbenone (?)‐ 2e to the norcampholenal analogue (+)‐ 19a . Reduction and subsequent protection afforded the silyl ether (?)‐ 19c , which was stereoselectively hydroborated under oxidative condition to afford the secondary alcohol (+)‐ 20c . Further oxidation and epimerization furnished the trans‐ketone (?)‐ 17a , a known intermediate of either (+)‐β‐necrodol (= (+)‐(1S,3S)‐2,2,3‐trimethyl‐4‐methylenecyclopentanemethanol; 17c ) or (+)‐(Z)‐lancifolol (= (1S,3R,4Z)‐2,2,3‐trimethyl‐4‐(4‐methylpent‐3‐enylidene)cyclopentanemethanol). Finally, hydrogenation of (+)‐ 4b gave the saturated cis‐aldehyde (+)‐ 21 , readily reduced to its corresponding alcohol (+)‐ 22a . Similarly, hydrogenation of β‐campholenol (= 2,3,3‐trimethylcyclopent‐1‐ene‐1‐ethanol) gave access via the cis‐alcohol rac‐ 23a , to the cis‐aldehyde rac‐ 24 .