Isoochotensine,a New Spirobenzyusoquinoline Alkaloid from: Corydalis Ochotensis Turcz

Separation of the phenolic fraction of Corydalis ochotensis afforded a new spirobenzylisoquinoline alkaloid, isoochotensine ( 1 ) and three known alkaloids, ochotensine ( 3 ), cheilanthifoline ( 7 ), and lienkonine ( 9 ) as their acetyl derivatives together with a known nonphenolic alkaloid, ochotensimine ( 5 ). Their structures were elucidated by the spectral data.     

A New Nitro Alkaloid from Corydalis saxicola Bunting

A new nitro tetrahydronprotoberberins alkaloid, 1-nitro-apocavidine was isolated from Corydalis saxicola Bunting. The structure was established by spectroscopic methods.     

Erythrinarbine,a Novel nor-A ring Erythrina Alkaloid from Erythrina arborescens

ErythrinaarborescensRoxb.belongstoErythrinagenusofPapilionaceaefamilyplants,andiswidelydistributedintropicalandsubtropicalregionsoftheworld,aswellasinthesouthandsouth-westofChina'.AsaChinesefolkmedicine,itsrootandstemareusedtotreatrheumatismanddysentery'.TheErythrinaalkaloids,normallyaC.,tetracyclicspiroaminesystem,erythrinanel,arethecharacteristicconstituentsinErylhrinagenusandabout100erythrinaalkaloidshavebeensofarreportedfromthisgenusplants'-'.MostoftheseErythrinaalkaloidshaveatetrahydr…     

Antihypertensive Activity of dl-Tetrahydropalmatine,an Active Alkaloid Isolated from the Tubers of Corydalis racemosa

The antihypertensive activity of dl-tetrahydropalmatine hydrochloride (THP), isolated from the tubers of Corydalis racemosa (Thunb.) Pers. (Papaveraceae), was investigated in spontaneously hypertensive rats (SHRs) using intravenous injection. A dose-dependent lowering of blood pressure was observed in SHRs. Decrease of plasma noradrenaline was also obtained in SHRs that received injection of THP. Direct injection of THP into brain lowered the blood pressure and plasma noradrenaline. This antihypertensive action of THP appears to be produced mainly by an effect on central nervous system to lower sympathetic tone in SHRs.     

Huperzine W,a Novel 14 Carbons Lycopodium Alkaloid from Huperzia serrata

Lycopodium plants have long been studied and many alkaloids have been reported thus far. Most of the compounds reported have a common formula of C16N1. During the course of chemical investigation on Huperzia serrata, we gained huperzine W (1, 25 mg from 10 kg dry whole plant), a novel compound which possessed a unique structure among Lycopodium alkaloids, along with a known compound, alopecuridine (2)2. In present paper, we report on the isolation and structural elucidation of 1. 1 2 H…     

A Novel Alkaloid from Stemona parviflora

A novel alkaloid was isolated from the stems and leaves of Stemona parviflora Wright Based on the spectral methods,its structure was elucidated as parvineostemonine.     

A Novel Alkaloid from Melodinus henryi

The isolation and structure elucidation of a novel alkaloid, namely of the 14‐O‐ethyl‐substituted (3α,14α,16α)‐2,7‐secoeburnamine derivative 1 from the leaf of Melodinus henryi is reported. Ten known alkaloids were also isolated. Their structures were determined spectroscopically. The isolates were evaluated for their cytotoxicity.     

Inhibition of Glutamate Release from Rat Cortical Nerve Terminals by Dehydrocorydaline,an Alkaloid from Corydalis yanhusuo

Excessive release of glutamate induces excitotoxicity and causes neuronal damage in several neurodegenerative diseases. Natural products have emerged as potential neuroprotective agents for preventing and treating neurological disorders. Dehydrocorydaline (DHC), an active alkaloid compound isolated from Corydalis yanhusuo, possesses neuroprotective capacity. The present study investigated the effect of DHC on glutamate release using a rat brain cortical synaptosome model. Our results indicate that DHC inhibited 4-aminopyridine (4-AP)-evoked glutamate release and elevated intrasynaptosomal calcium levels. The inhibitory effect of DHC on 4-AP-evoked glutamate release was prevented in the presence of the vesicular transporter inhibitor bafilomycin A1 and the N- and P/Q-type Ca²⁺ channel blocker ω-conotoxin MVIIC but not the intracellular inhibitor of Ca²⁺ release dantrolene or the mitochondrial Na⁺/Ca²⁺ exchanger inhibitor {"type":"entrez-protein","attrs":{"text":"CGP37157","term_id":"875406365","term_text":"CGP37157"}}CGP37157. Moreover, the inhibitory effect of DHC on evoked glutamate release was prevented by the mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) inhibitor PD98059. Western blotting data in synaptosomes also showed that DHC significantly decreased the level of ERK1/2 phosphorylation and synaptic vesicle-associated protein synapsin I, the main presynaptic target of ERK. Together, these results suggest that DHC inhibits presynaptic glutamate release from cerebrocortical synaptosomes by suppressing presynaptic voltage-dependent Ca²⁺ entry and the MAPK/ERK/synapsin I signaling pathway.     

Annosqualine: a Novel Alkaloid from the Stems of Annona squamosa

Annosqualine (=(10′bR)‐1′,5′,6′,10′b‐tetrahydro‐9′‐hydroxy‐7′,8′‐dimethoxyspiro[cyclohexa‐2,5‐diene‐1,2′‐pyrrolo[2,1‐a]isoquinoline]‐3′,4‐dione; 1 ), a novel alkaloid with an unprecedented skeleton, and a new amide, dihydrosinapoyltyramine (=3‐(4‐hydroxy‐3,5‐dimethoxyphenyl)‐N‐[2‐(4‐hydroxyphenyl)ethyl]propanamide; 2 ), were isolated from the stems of Annona squamosa L., together with six known alkaloids. The structures of all compounds were elucidated spectroscopically by means of optical rotation, ¹H‐, ¹³C‐, and 2D‐NMR, and by EI‐MS, or by comparison with the spectral data of authentic samples. A possible biogenetical pathway towards annosqualine ( 1 ) is proposed.     

Two Novel Monoterpene Alkaloid Dimers from Incarvillea arguta

Two novel monoterpene alkaloid dimers, named argutanes A and B ( 1 and 2 , resp.), together with the known alkaloid boschniakine ( 3 ), were isolated from the roots of Incarvillea arguta. The structures were elucidated on the basis of 1D‐ and 2D‐NMR, as well as HR‐ESI‐MS data.     

云南萝芙木花新吲哚生物碱

从云南萝芙木(Rauvolfia yunnanensis Tsiang)花乙酸乙酯提取物中分离得到9个化合物(其中4个为吲哚类生物碱), 即(18Z)-11-methoxypicrinine(1), caberoline(2), 11-methoxystrictamine(3)和strictamine(4), 以及russulamide(5), ursolic acid(6), urs-12(13)-en-3α-yl acetate(7), β-amyryl nonanoate(8)和β-sitosterol(9); 采用UV, IR, MS和1D, 2D NMR方法对化合物的结构进行了鉴定, 其中化合物1为新吲哚生物碱, 化合物5, 7和8系首次从该植物中分离得到, 但未得到利血平和育亨宾.     

Misenine,a Novel Macrocyclic Alkaloid with an Unusual Skeleton from the Mediterranean Sponge Reniera sp

PolycycJic marine alkaloids containing 3-alkylpyridine or partially reduced 3-alkylpyridine as basic building blocks represent an emerging and intriguing group of bioactive natural products from marine sponges. Since halitoxin,² the first example of this kind of alkaloid, was reported in 1978, many related alkaloids have been discovered from sponges of the order Haplosclerida. All of these alkaloids, in spite of formally exhibiting quite different frameworks, could biogeneticaliy derive from bis-3-alkylpyridine or reduced bis-3-alkylpyridine units. In the last decade, the knowledge of this fascinating group of compounds has increased remarkably. A recent review has exhaustively studied occurrence, distribution, plausible biogenetic origin and relatedness, as well as biological activities, of 3-alkylpyridine derived marine alkaloids.³     

Sinoraculine,the Precursor of the Novel Alkaloid Sinoracutine from Stephania cepharantha Hayata

A new alkaloid, sinoraculine, the precursor of the novel alkaloid sinoracutine, was isolated from the leaves and stems of Stephania cepharantha, and its structure was elucidated by spectroscopic analyses.     

Turtschamide,a cytotoxic putrescine bisamide from Corydalis turtschaninovii

A putrescine bisamide with a unique cyclic structure derived from l-tyrosine, turtschamide (1), was isolated from the tubers of Corydalis turtschaninovii. The structure of 1 was established by extensive spectroscopic study, and its absolute configuration was determined by a combination of NOE experiment and application of the Marfey’s method. Turtschamide (1) exhibited cytotoxicity against the A549, SK-OV-3, SK-MEL-2, and HCT-15 cells.     

Delcorinine, a New Alkaloid from Delphinium corymbosum

The aerial part ofD. Corymbosumyielded delcoridine and a new C ₁₉ -norditerpenoid alkaloid delcorinine. The structure of delcorinine was established using spectral data and correlation with delcorine and delsoline     

Trichocarpinine,a Novel Hetidine–Hetisine Type Bisditerpenoid Alkaloid from Aconitum tanguticum var. trichocarpum

Trichocarpinine ( 1 ), the first hetidine–hetisine type bisditerpenoid alkaloid, was isolated from the whole herbs of Aconitum tanguticum var. trichocarpum. Its structure was determined by a combination of spectroscopic techniques, including HR‐ESI‐MS and 1D‐ and 2D‐NMR experiments. Its plausible biogenetic pathway was proposed as well (Scheme).     

Geissospermiculatine,a New Alkaloid from Geissospermum reticulatum Bark

A new alkaloid, geissospermiculatine was characterized in Geissospermum reticulatum A. H. Gentry bark (Apocynaceae). Here, following a simplified isolation protocol, the structure of the alkaloid was elucidated through GC-MS, LC-MS/MS, 1D, and 2D NMR (COSY, ROESY, HSQC, HMBC, ¹H-¹⁵N HMBC). Cytotoxic properties were evaluated in vitro on malignant THP-1 cells, and the results demonstrated that the cytotoxicity of the alkaloid (30  μg/mL) was comparable with staurosporine (10  μM). Additionally, the toxicity was tested on zebrafish (Danio rerio) embryos in vivo by monitoring their development (0–72 h); toxicity was not evident at 30  μg/mL.