祁州漏芦蜕皮甾酮类化学成分的研究

从祁州漏芦[Rhaponticum uniflorum(L.)DC.]的根中,分离出三个蜕皮甾酮类化合物Ⅰ,Ⅱ,Ⅲ,其中Ⅱ根据UV,IR,MS,¹³CNMR,¹HNMR,¹H-¹HCOSY,¹H-¹HNOESY,¹H-¹³C COSY,及CD谱确定其结构为(20R,22R,24S)-2β,3β,11α,14α,20,22,24-heptahydroxy-5β-cholest-7-en-6-one,为一新化合物,命名为漏芦甾酮(rhaponfisterone)。化合物Ⅰ和Ⅲ分别鉴定为蜕皮甾酮(ecdysterone)和土克甾酮(turkesterone)。     

New polyoxygenated steroids from the South China Sea gorgonian Echinogorgia aurantiaca

Three new polyoxygenated steroids, named 3beta,7alpha,9alpha-trihydroxy-cholestan-6-one (1), 3beta,5alpha,6beta-trihydroxycholestan-1-one (2) and cholestane-3beta,5alpha,6beta,11beta-tetrol (3), along with four known steroids (4-7) were isolated from the South China Sea gorgonian Echinogorgia aurantiaca. The structures of 1-3 were established by extensive spectroscopic analysis, including 1D and 2D NMR data.     

Bioactive triterpenoids from Symplocos chinensis

A new triterpenoid, 2beta,3beta,19alpha,24-tetrahydroxy-23-norurs-12-en-28-oic acid (4), together with three known triterpenoids 3-oxo-19alpha,23,24-trihydroxyurs-12-en-28-oic acid (1), 2alpha,3beta,19alpha,23-tetrahydroxyurs-12-en-28-oic acid (2), 2alpha,3alpha,19alpha,23-tetrahydroxyurs-12-en-28-oic acid (3), was isolated from the roots of Symplocos chinensis. The new triterpenoid shows significant cytotoxic activity against B16 and BGC-823 cells.     

New sesquiterpenes from the roots of Ligularia dentata

Phytochemical investigation of the roots of Ligularia dentata has resulted in the isolation of three new bisabolane sesquiterpenes: 1alpha,3beta,10,11 -tetrahydroxy-2alpha,5alpha,8-triangeloyl-oxybisabola-(7)14-en-4-one, 1alpha,3beta,10-trihydroxy-11 -methoxy-2alpha,5alpha,8-triangeloyloxybisabola-7(14)-en-4-one, and lalpha, 3beta,10-trihydroxy-2alpha,5alpha,8-triangeloyloxybisabola-7(14),11(12)-dien-4-one. Their structures were elucidated with spectro-scopic methods and 2D-NMR techniques as well as chemical transformations. In addition, three known phenolic norsesquiterpenes, liguhodgsonal, ligujapone, and 2-hydroxy-platyphyllide have also been obtained.     

Four new terpenoids from the roots of Ligularia narynensis

Four new oplopane and guaiane type sesquiterpenoids (1-3), and a monoterpenoid (4) together with three known monoterpenoids (5-7), have been isolated from the roots of Ligularia narynensis. The structures of 1-4 were elucidated as 3beta,4-diacetoxy-8alpha-(2-methylbutyryloxy)-9alpha-(4-methylsenecioyloxy)-11alpha,12-epoxyoplop-10 (14)-ene (1), 3beta,4-diacetoxy-9alpha-(4-acetoxy-4-methylsenecioyloxy)-2beta,8alpha-di (2-methylbutyryloxy)-11alpha,12-epoxyoplop-10 (14)-ene (2), 2alpha-hydroxy-1betaH,7alphaH,10alphaH-guai-4,11 (12)-dien-3-one (3) and 1alpha,2beta,3alpha,6alpha-tetrahydroxy-p-menthane (4) by spectroscopic methods. 1 and 2 were evaluated for their in vitro cytotoxic activity against cultured SMMC-7721 (human hepatoma), L02 (human hepatocyte), and HL-60 (human promyelocytic leukaemia) cell lines.     

New dammaranes, esterified with malonic acid, from leaves of Betula pendula

Three known and five new dammarane triterpenes, esterified with malonic acid at C-3 with hemolytic activity were identified from the ethanol-water extract of leaves of Betula pendula Roth: 12-O-acetyl-3alpha,12beta,20(S),24(R)-tetrahydroxydammar-25-en-3-yl hydrogen propanedioate, 12-O-acetyl-3alpha,12beta20(S),24(S)-tetrahydroxydammar-25-en-3-yl hydrogen propanedionate, 12-O-acetyl-3alpha,12beta,17alpha,20(S),24(R)-pentahydroxydammar-25-en-3-yl hydrogen propanedioate, [12beta-acetoxy-4,4,8,10,14-pentamethyl-17-(2-methyl-5-oxotetrahydrofuran2(S)-yl)-hexadecahydrocyclopenta[A]phenanthren-3alpha-yl] hydrogen propanedioate, 12- O-acetyl-3alpha,12beta,20(S),25-pentahydroxydammar-23(E)-en-3-yl hydrogen propanedioate, and one which was new for Betula pendula but found in other Betula species: 12-O-acetyl-20,24-epoxy-3alpha,12beta,20(S),24(R),25-pentahydroxydammar-3-yl hydrogen propanedioate. The structures were elucidated by MS, (1)H-NMR, (13)C-NMR, (1)H-(1)H-COSY, DEPT, (1)H-(13)C-NMR (HMQC, HMBC) experiments.     

Germacrane sesquiterpene esters from Salvia roborowskii

From the whole plant of Salvia roborowskii, four new germacrane sesquiterpene esters, 3beta,6beta,8alpha-triacetoxy-4beta,5alpha-epoxy-1-oxogermacr-10(14)-ene, 3beta,6beta,8alpha-triacetoxy-4beta,5alpha-epoxygermacr-1 (10) E-ene, 3beta,6beta,8alpha-triacetoxy-4beta,5alpha:1alpha,10beta-diepoxygermacrane and 6beta-acetoxyglechomafuran were isolated, and their structures were elucidated by spectroscopic methods including 2D NMR techniques (1H-1H COSY and 1H-1H NOESY for 1).     

Influence of recombinant gamma-aminobutyric acid-A receptor subunit composition on the action of allosteric modulators of gamma-aminobutyric acid-gated Cl- currents.

gamma-Aminobutyric acid (GABA)-activated Cl- currents in neonatal rat cortical neurons and in cultured cells engineered for the expression of specific molecular forms of the GABAA receptor alpha, beta, and gamma subunits, were recorded with the patch-clamp technique in the whole-cell configuration. The effects of various allosteric modulators of GABAA receptors were determined. Diazepam and clonazepam showed greater efficacy as positive modulators of GABA-elicited currents in alpha 2 beta 1 gamma 2 or alpha 3 beta 1 gamma 2 receptors than in alpha 1 beta 1 gamma 2 or alpha 5 beta 1 gamma 2 receptors or in cortical neurons. Alpidem was more efficacious at alpha 1 beta 1 gamma 2 or alpha 2 beta 1 gamma 2 receptors than at alpha 1 beta 1 gamma 2 or alpha 5 beta 1 gamma 2 receptors or in cortical neurons. Conversely, zolpidem was equally efficacious for all these receptors except for alpha 5 beta 1 gamma 2. Both imidazopyridines (alpidem and zolpidem) were virtually ineffective at modulating the GABA response of alpha 5 beta 1 gamma 2 receptors and in almost all the receptors assembled from alpha 1, alpha 2, alpha 3 or alpha 5 subunits together with beta 1 and gamma 1 subunits. The beta-carboline derivatives methyl-6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate (DMCM) and methyl-beta-carboline-3-carboxylate (beta-CCM) elicited a positive allosteric modulation of alpha 1 beta 1 gamma 1 or alpha 2 beta 1 gamma 1 receptors, whereas they acted as negative allosteric modulators at nearly all other receptors tested, as they do in cortical neurons. Although the positive allosteric modulation by beta-carbolines never exceeded a doubling of the GABA response, DMCM was more efficacious at alpha 1 beta 1 gamma 1 receptors and beta-CCM was more efficacious at alpha 2 beta 1 gamma 1 receptors. DMCM was inactive at alpha 3 beta 1 gamma 1 receptors, whereas beta-CCM was virtually inactive at alpha 5 beta 1 gamma 1 receptors. The benzodiazepine 4'-chlorodiazepam, which is a negative modulator resistent to flumazenil inhibition, acted at all the various GABAA receptors that contained a gamma subunit.     

Two new triterpenoids from the fresh leaves of Psidium guajava

Two new triterpenoids, guajavolide (2 alpha,3 beta,6 beta,23-tetrahydroxyurs-12-en-28,20 beta-olide; 1) and guavenoic acid (2 alpha,3 beta,6 beta,23-tetrahydroxyurs-12,20(30)-dien-28-oic acid; 2) along with one known triterpene oleanolic acid (3) were isolated from the fresh leaves of Psidium guajava. Their structure elucidation and stereochemistry were determined by spectroscopic experiments, including 2D-NMR techniques.     

New cytotoxic sesquiterpene lactones from Warionia saharae

Cytotoxicity-guided fractionation of the methanol soluble part of the dichloromethane extract of the leaves of Warionia saharae led to the isolation of the two new guaianolide-type sesquiterpene lactones, 5 alpha H-3 beta,4 beta-epoxy-14-oxo-guaia-1(10),11(13)-dien-6 alpha,12-olide (1), 5 alpha H-2 beta,4 beta-epoxy-3 alpha-hydroxy-guaia-1(10),11(13)-dien-6 alpha,12-olide (6), and the new eudesmane type sesquiterpene 1 beta,6 alpha-dihydroxycostic acid ( 4). In addition, the known sesquiterpene lactones 5 alpha H-2 beta-hydroxyguaia-3(4),10(14),11(13)-trien-6 alpha,12-olide (2), reynosin (3), 5 alpha H-1 alpha,10 alpha:3 alpha,4 alpha-diepoxyguaia-11(13)-en-6 alpha,12-olide (5), and dehydroleucodin (7) were isolated together with the known flavone hispidulin. Cytotoxicity testing of the sesquiterpene lactones against the KB cancer cell line (ATCC CCL17) revealed IC50 values of 3.5 (1), 2.6 ( 2), 2.7 ( 3), 4.3 ( 5), 3.6 ( 6), and 1.3 (7) microg/mL. Compound 4 was not active up to 20 microg/mL.     

A new sesquiterpene ester from the fruits of Celastrus orbiculatus

From the fruits of Celastrus orbiculatus Thunb., a new dihydroagarofuran sesquiterpene ester named 6alpha,13[beta-diacetoxy-1beta,8beta,9beta-tribenzoyloxy-beta-dihydroagarofuran (1) has been isolated, along with three known compounds: 1beta,6alpha,8beta-triacetoxy-9alpha-benzoyloxy-beta-agarofuran (2), 1beta,6alpha-diacetoxy-9alpha-benzoyloxy-beta-dihydroagarofuran (3) and beta-sitostrol (4). The structure of 1 was elucidated on the basis of spectroscopic methods.     

Ligand design for alpha(1) adrenoceptors

An area of continuing interest in medicinal chemistry is the design, synthesis and pharmacological evaluation of ligands which bind at adrenoceptor subtypes, which include alpha(1A), alpha(1B), alpha(1D); alpha(2A), alpha(2B), alpha(2C); beta(1), beta(2), beta(3) and possibly beta(4) subtypes. The selective blockade or stimulation of these receptor subtypes is of on-going pharmacological and medicinal interest. However, the design principles for ligand differentiation at these subtypes still need further development. This review focuses on alpha(1) adrenoceptors with a concentration on literature over the past five years. Structural, physiological and therapeutic aspects of the alpha(1A), alpha(1B) and alpha(1D) subtypes are discussed together with ligands binding to these receptor subtypes. Approaches to alpha(1) adrenoceptor ligand design based on known ligands and on receptor docking are evaluated. A new combined approach using pharmacophores and receptor docking affords possibilities for deeper insights into achieving small molecule binding selectivity.     

Vascular adrenoceptors: an update

The total and regional peripheral resistance and capacitance of the vascular system is regulated by the sympathetic nervous system, which influences the vasculature mainly through changes in the release of catecholamines from both the sympathetic nerve terminals and the adrenal medulla. The knowledge of the targets for noradrenaline and adrenaline, the main endogenous catecholamines mediating that influence, has recently been greatly expanded. From two types of adrenoceptors (alpha and beta), we have now nine subtypes (alpha1A, alpha1B, alpha1D, alpha2A/D, alpha2B, alpha2A/D, beta1, beta2, and beta3) and two other candidates (alpha1L and beta4), which may be conformational states of alpha1A and beta1-adrenoceptors, respectively. The vascular endothelium is now known to be more than a pure anatomical entity, which smoothly contacts the blood and forms a passive barrier against plasma lipids. Instead, the endothelium is an important organ possessing at least five different adrenoceptor subtypes (alpha2A/D, alpha2C, beta1, beta2, and beta3), which either directly or through the release of nitric oxide actively participate in the regulation of the vascular tone. The availability of transgenic models has resulted in a stepwise progression toward the identification of the role of each adrenoceptor subtype in the regulation of blood pressure and fine-tuning of blood supply to the different organs: alpha2A/D-adrenoceptors are involved in the central control of blood pressure; alpha1-(primarily) and alpha2B-adrenoceptors (secondarily) contribute to the peripheral regulation of vascular tone; and alpha2A/D- and alpha2C-adrenoceptors modulate transmitter release. The increased knowledge on the involvement of vascular adrenoceptors in many diseases like Raynaud's, scleroderma, several neurological degenerative diseases (familial amyloidotic polyneuropathy, Parkinson disease, multiple-system atrophy), some kinds of hypertension, etc., will contribute to new and better therapeutic approaches.     

白木通中一个新的三萜皂苷类化合物

目的研究木通科植物白木通藤茎的化学成分。方法通过反复硅胶柱色谱、ODS柱色谱和重结晶等方法进行分离纯化，根据化合物的理化性质和波谱数据鉴定结构。结果从白木通藤茎70%乙醇提取物中分离得到6个化合物。分别鉴定为2α,3β,23-trihydroxyolean-12-en-28-oic acid =O-β-D-xylopyranosyl-(1→3)-O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (I), 2α,3β,23-trihydroxyurs-12-en-28-oic acid O-β-D-xylopyranosyl-(1→3)-O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (II), 2α,3β,23-trihydroxyolean-12-en-28-oic acid O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (III), 2α,3β,23-trihydroxyurs-12-en-28-oic acid O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (IV), 2α,3β,23-trihydroxyolean-12-en-28-oic acid O-β-D-glucopyranosyl ester (V), 2α,3β,23-trihydroxyurs-12-en-28-oic acid O-β-D-glucopyranosyl ester (VI)。结论化合物II为新化合物，命名为mutongsaponin C，其他均为首次从该植物藤茎中分离得到。     

Three new taxoids from the seeds of Japanese yew, Taxus cuspidata

Five taxane diterpenoids were isolated from the seeds of the Japanese yew, Taxus cuspidata Sieb. et Zucc. The structures were established as 2 alpha,7 beta,13 alpha-triacetoxy-5 alpha-(3'-dimethylamino-3'-phenyl)-propionyloxy-2(3-->20)-aboe+ ++-taxa-9,10-dione (1) and 2 alpha,7 beta,9 alpha,10 beta-tetraacetoxy-5 alpha-[(2R,3S),N,N-dimethyl-3-phenylisoseryloxy]-taxa-4(20),11- dien-13-one (2), 2 alpha, 9 alpha, 10 beta-triacetoxy-5 alpha-cinnamoxy-taxa-4(20),11-diene-13 alpha-ol (3), taxezopidine J (4), and taxuspine D (5) on the basis of 1D, 2D NMR, and MS spectral analysis. Compounds 1, 2, and 3 are new compounds.     

Glycine receptor beta subunits play a critical role in potentiation of glycine responses by ICS-205,930

The sensitivity of various types of recombinant glycine receptors (GlyRs) to ICS-205,930 was studied by fast perfusion in Xenopus laevis oocytes. This compound has previously been shown to potentiate glycine responses in rat spinal neurons between 10 nM and 1 microM, independently of its 5-HT(3) antagonist properties. In contrast, submicromolar concentrations of ICS-205,930 failed to affect responses of homomeric GlyRs formed from human alpha1 or alpha2 subunits, and micromolar concentrations (1-20 microM) acted differentially on the two types of homomeric receptors, potentiating the responses to glycine (10-20 microM) of alpha1 homomeric GlyRs and inhibiting the responses of alpha2 homomeric GlyRs. GlyRs beta subunits markedly influenced the modulations induced by ICS-205,930. In oocytes expressing alpha1/beta or alpha2/beta heteromeric GlyRs, low concentrations of ICS-205,930 (20 nM-1 microM) induced a potentiation of glycine responses that was counteracted by an inhibitory effect at higher concentrations. Thus, GlyRs beta subunits reduce by 2 orders of magnitude the concentration range potentiating alpha1-containing GlyRs and are required for potentiation of alpha2-containing GlyRs. These results reveal a new high-affinity potentiating site on GlyRs, to which beta subunits participate. The difference in ICS sensitivity between alpha1 and alpha2 GlyRs cannot be explained by their difference in TM2 segment and extracellular domains partly conserved between glycine and 5-HT(3) receptors are probably involved in the interaction of some 5-HT(3) antagonists with GlyRs.     

Two new sesquiterpene lactones from Sarcandra glabra

Two new sesquiterpene lactones (1) and (2), along with three known sesquiterpenes, atractylenolide beta (3), chloranthalactone E (4), and ( - )-istanbulin A (5), were isolated from the whole plant of Sarcandra glabra. The structures of two new compounds were established as 8beta,9alpha-dihydroxyeudesman-4(15),7(11)-dien-8alpha,12-olide (1) and 8beta,9alpha-dihydroxylindan-4(5),7 (11)-dien-8alpha,12-olide (2) on the basis of spectroscopic analysis. Compound 3 was isolated from this genus for the first time.     

New eremophilenolides from Cacalia pilgeriana

Five new eremophilenolides and a known sesquiterpene were isolated from the methanol extract of the roots of Cacalia pilgeriana. Their structures were identified as 1 beta-hydroxy-2 beta-methyl-senecioyloxyeremophil-7(11)-en-8 beta(12)-olide (1), 1 beta-hydroxy-2 beta-methylsenecioyloxy-8 alpha-methoxyeremophil-7(11)-en- 8 beta(12)-olide, 2 beta-hydroxy-3 beta-methylsenecioyloxyeremophil-7(11)-en-8 alpha(12)-olide ( 3), 2 beta,8 beta-dihydroxy-3 beta-methylsenecioyloxyeremophil-7(11)-en-8 alpha(12)-olide and 1 beta,8 beta-dihydroxy-2 beta,3 alpha-diangeloyloxyeremophil-7(11)-en-8 alpha(12)-olide ( 5) and caryolane-1,9 beta-diol by spectroscopic methods including 2D-NMR techniques ( (1)H- (1)H COSY, HMQC, HMBC) and HR-ESI-MS. The structure and relative stereochemistry of compound 1 were unequivocally established by X-ray diffraction analysis. Bioassays showed compounds 3 and 5 to possess strong cytotoxic activity in vitro against human leukemia cells (HL-60) (IC (50) < 15 microg mL (-1)). The structure-activity relationship is discussed.     

New macrocyclic diterpenoids from Euphorbia esula

The structures of two new macrocyclic jatrophane diterpenoid esters from the whole herb of Euphorbia esula, were established as 11,14-epoxy-3beta,5alpha,7beta,8alpha,9alpha,15beta-hexaacetoxy-12-oxo-13alphaH-jatropha-6(17)-ene (1) and 1alpha,3beta-diacetoxy-5alpha,7beta-dibenzoyloxy-9,14-dioxo-11beta,12alpha-epoxy-2alpha,8alpha,15beta-trihydroxy-13betaH-jatropha-6(17)-ene (2) by a combination of 1D- and 2D-NMR techniques as well as UV, IR and mass spectral data. Bioassay evaluation of all isolates against the human tumor cell lines (B16, KB, SMMC and BGC) indicated that ester 2 was cytotoxic to B16 with the IC50 value being 1.81 microg/ml. In addition, the irritant activity assay indicated that both diterpenoids were inactive (ID(24)50 > 100 microg/ear).     

Effects of isoflurane and hexafluorodiethyl ether on human recombinant GABA(A) receptors expressed in Sf9 cells.

Effects of volatile anesthetics and a volatile convulsant on human recombinant gamma-aminobutyric acid (GABA) type A receptor responses were studied using the whole cell configuration of the patch clamp technique. Sf9 cells were transfected with bacuroviruses carrying cDNAs of alpha1beta2, alpha1beta2gamma2s, alpha3beta2 and alpha3beta2gamma2s subunit combinations of the human GABA(A) receptor. Clinical concentrations of isoflurane (a volatile anesthetic) enhanced the GABA-induced current of the alpha1beta2gamma2s and alpha3beta2gamma2s GABA(A) subunit combinations. On the other hand, isoflurane suppressed the current of the alpha1beta2 and alpha3beta2 subunit combinations, indicating that the anesthetic effects depended upon the presence of gamma2s subunit. A high concentration (2 mM) of isoflurane generated a surge current following the washout of GABA and the anesthetic. Hexafluorodiethyl ether (a volatile convulsant) decreased the GABA-response of the both alpha3beta2gamma2s and alpha3beta2 constructs without generating a surge current. The results suggest that volatile agents affect the receptor-ionophore complex via direct interaction with proteins but not through a perturbation of the membrane lipid environment. A hypothetical sequential model for the anesthetic action is presented.