旱前胡的化学成分

从云南产早前胡(Ligusticum daucoides Franch.)(伞形科)根的脂溶性部分分离了11个化合物,分别为香豆素化合物:columbianadin,isoedultin,archangelicin,旱前胡甲素(daucoidin A),旱前胡乙素(dsucoidin B),佛手柑内酯(bergapten),非香豆素化合物:falcarindiol(7),阿魏酸(ferulic acid),蜡酸(cerotic acid),β-谷甾醇(β-sitosterol),胡萝卜甙(daucosterol)。其中,化合物4和5是新的香豆素化合物,经化学方法及光谱测定,证明其结构为:4是3′去乙酰基isoedultin,即:2′(S)-(1″,1″-二甲基,1″-当归酰氧基)-3′(R)-羟基-角型二氢呋喃香豆素[2′(S)-(1″,1″-dimethvl,1″-angelovloxv)—3′(R)-hydroxy angular dihydrofuranocoumarin];5是2′-(1″-甲基,1″-羟基,1″-当归酰氧亚甲基)-角型二氢呋喃香豆素[2′-(1″-methyl,1″-hydroXy,1″-angeloyloxy-methylene)angular dihydrofuranocoumarin]。     

广西前胡的香豆素成分

从广西前胡Peucedaum guangxieuse Shan et Sheh根及根茎的乙醇提取物中,经硅胶柱层析分析8个化合物,分别鉴定为：香豆素化合物广西前胡素（peguangxenin)(1),白花前胡丁素[( )anomalin](2),伞形花内酯(umbellferone)(3),欧芹属乙素（imperatorin）(4),虎耳草素(pimpinellin)(5);其它类型化合物,falcarindiol(6),阿魏酸(ferulic acid)(7),β-谷甾醇（β-sitosterol）.其中广西前胡素（1）是新化合物,经光谱及化学方法推证其结构为3′(S)-千里光酰氧基-4′（S）-羟基-二氢邪蒿素。     

芽前胡的化学成分

从成都产芽前胡Peucedanum turgeniifolium Wolff.中分离鉴定了12个化合物,分别为香豆素化合物佛手柑内酯(bergapten)(1),异欧芹属乙素(isoimperatorin)(2),(±)diisovaleryl-cis-khellactone(3),(±)dihydrosamidin(4),(±)peuformosin(5),(±)cis-khellactone(6),8-(2’,3’-二羟基,3’-甲基-丁基)-伞形花内酯[8-(2’3’-dihydroxy,3’-methyl-butyl)-umbelliferone](7),(±)selinidin(8),turgeniifolin A(9)以及非香豆素化合物硬脂酸(stearic acid),β-谷甾醇(β-sitosterol),甘露醇(d-mannitol)。     

马山前胡的香豆素

从马山前胡(Peucedanum mashanense Shan et Sheh)中分离得到4个化合物,鉴定为香豆素化合物白花前胡丙素[( )pareruptorin A],白花前胡丁素[( )anomalin],虎耳草素(pimpinellin)和β-谷甾醇(β-sitosterol)。     

细裂前胡的香豆素成分

细裂前胡Peucedanum macilentum Franch。(伞形科)是云南西部应用的前胡地方品种,从其根的乙醇提取物中经硅胶柱层析得到6个化合物,分别鉴定为香豆素类化合物:伞形花内酯(umbelliferone)(1),佛手柑内酯(bergapten)(2),laserpitin(3),异白花前胡丁素(anomalin)(4);其它化合物:阿魏酸(ferulic acid)(5),β-谷甾醇(β-sitosterol)。     

诺丽发酵果汁化学成分及抗氧化活性研究

采用多种色谱技术从诺丽(Morinda citrifolia)发酵果汁中分离得到10个化合物,并应用波谱学方法进行结构鉴定,分别鉴定为6,7-二羟基香豆素(1)、7-羟基香豆素(2)、东莨菪亭(3)、6-羟基-7-甲氧基香豆素(4)、7-羟基-4-甲基香豆素(5)、1,2,3,4-四氢-β-咔啉-3-羧酸(6)、(1S,3S)-1-甲基-1,2,3,4-四氢-β-咔啉-3-羧酸(7)、(1R,3S)-1-甲基-1,2,3,4-四氢-β-咔啉-3-羧酸(8)、对羟基苯甲酸(9)、龙胆酸(10)。利用DPPH和ABTS+·自由基清除能力法进行抗氧化活性测定,其中化合物1、3、4、10抗氧化活性较强,化合物1和10清除DPPH和ABTS+·自由基能力的IC50值分别为160.87、8.32和6.17、9.71μmol/L。化合物2、5~8均系首次从该植物中分离,本研究得到诺丽发酵果汁中香豆素、有机酸和生物碱三类成分,并且化合物1、3、4、10抗氧化活性良好。     

俯卧前胡的化学成分

从伞形科植物俯卧前胡(Peucedanum decumbens Maxiam)的根中分离鉴定了13个成分,其中化合物(1)是一个新的二氢呋喃香豆素,经各项光谱测定,确定其结构为:顺式-2′-(1″-甲基,1″-千里光酰氧基-乙基)-3′-羟基-线型二氢呋喃香豆素,命名为俯卧前胡素(decumbensol)。     

开口箭根茎中甾体化合物的研究

从开口箭根茎部位共分离得到9个甾体化合物,经波谱数据分析结合文献对照分别鉴定为3-epi-neoruscogenin-3-β-D-glucopyranoside(1),3-epi-ruscogenin-3-β-D-glucopyranoside(2),ranmogenin A(3),convallagenin B(4),3-epi-neoruscogenin(5),tupichigenin E(6),(20S,22R)-spirost-25(27)-ene-1β,2β,3β,4β,5β,7α-hexaol-6-one(7),β-谷甾醇(8)和胡萝卜苷(9)。其中化合物1、2和4为首次从该植物中分离得到。     

木奶果茎叶的化学成分研究

采用常压柱色谱和重结晶相结合的分离方法,从木奶果的茎叶提取物的乙酸乙酯部分中分离得到8个化合物,通过波谱方法及与已知样品对照的手段鉴定它们为(2S,3S,4R)-2-[(2R)-2-hydroxytetracosanoyl-amino]-1,3,4-octadecanetriol(1),Aralia cerebroside(2),(24S)-24-ethylcholesta-3β,5α,6β-triol(3),Stigmast-4-en-6β-ol-3-one(4),7-oxo-β-sitosterol(5),7α-methoxy-sigmast-5-en-3β-ol(6),β-sitosterol(7),daucosterol(8)。化合物1-6为首次从该种植物中发现的。     

两面针中的化学成分

研究两面针Zanthaxylum nitidum(Roxb．)DC根部乙醇提取物中的化学成分。采用硅胶柱层析方法进行分离和纯化,通过波谱分析鉴定分离得到的化合物的结构。共鉴定7种香豆素成分及2种其它类型成分,其中6种香豆素前文已作过报道。本文主要介绍三种化学成分即β-谷甾醇(1),5-methoxymarmesin(2),β-香树素(3)。其中5-methoxymarmesin为首次从该植物中分离得到的化合物。     

Carotenoids with a 5,6-dihydro-5,6-dihydroxy-beta-end group, from yellow sweet potato "Benimasari", Ipomoea batatas Lam

A series of carotenoids with a 5,6-dihydro-5,6-dihydroxy-beta-end group, named ipomoeaxanthins A (1), B (2), C1 (3) and C2 (4) were isolated from the flesh of yellow sweet potato "Benimasari", Ipomoea batatas Lam. Their structures were determined to be (5R,6S,3'R)-5,6-dihydro-beta,beta-carotene-5,6,3'-triol (1), (5R,6S,5'R,6'S)-5,6,5',6'-tetrahydro-beta,beta-carotene-5,6,5'6'-tetrol (2), (5R,6S,5'R,8'R)-5',8'-epoxy-5,6,5',8'-tetrahydro-beta,beta-carotene-5,6-diol (3), and (5R,6S,5'R,8'S)-5',8'-epoxy-5,6,5',8'-tetrahydro-beta,beta-carotene-5,6-diol (4) by UV-Vis, NMR, MS and CD data.     

Synthesis of radiolabeled biphenylsulfonamide matrix metalloproteinase inhibitors as new potential PET cancer imaging agents

Novel matrix metalloproteinase (MMP) inhibitor radiotracers, (S)-3-methyl-2-(2',3',4'-methoxybiphenyl-4-sulfonylamino)-butyric acid [(11)C]methyl ester (1a-c), (S)-3-methyl-2-(2',3',4'-fluorobiphenyl-4-sulfonylamino)-butyric acid [(11)C]methyl ester (1d-f), and (S)-3-methyl-2-(4'-nitrobiphenyl-4-sulfonylamino)-butyric acid [(11)C]methyl ester (1g), a series of substituted biphenylsulfonamide derivatives, have been synthesized for evaluation as new potential positron emission tomography (PET) cancer imaging agents.     

Stigmastane derivatives and isovaleryl sucrose esters from Vernonia guineensis (Asteraceae)

Vernoguinoside, 16beta,22R;21,23S-diepoxy-3beta-O-beta-D-glucopyranosyloxy-21S,24-dihydroxy-5alpha-stigmasta-8,14-dien-28-one (1), a new stigmastane derivative, 16beta,22R;21,23S-diepoxy-21S,24-dihydroxy-5alpha-stigmasta-8,14-diene-3,28-dione (2) and two new sucrose esters, 1',3,3',4',6'-pentakis-O-(3-methylbutanoyl)-beta-D-fructofuranosyl alpha-D-glucopyranoside (3) and 1',2,3',6,6'-pentakis-O-(3-methylbutanoyl)-beta-D-fructofuranosyl alpha-D-glucopyranoside (4), have been isolated from the stem bark of Vernonia guineensis. The structures of the new compounds were determined on the basis of spectroscopic evidence.     

Crystal structures of alpha-mercaptoacyldipeptides in the thermolysin active site: structural parameters for a Zn monodentation or bidentation in metalloendopeptidases.

Three alpha-mercaptoacyldipeptides differing essentially in the size of their C-terminal residues have been crystallized in the thermolysin active site. A new mode of binding was observed for 3 [HS-CH(CH(2)Ph)CO-Phe-Tyr] and 4 [HS-CH((CH(2))(4)CH(3))CO-Phe-Ala], in which the mercaptoacyl moieties act as bidentates with Zn-S and Zn-O distances of 2.3 and 2.4 A, respectively, the side chains fitting the S(1), S(1)', and S(2)' pockets. Moreover, a distance of 3.1 A between the sulfur atom and the OE1 of Glu(143) suggests that they are H-bonded and that one of these atoms is protonated. This H-bond network involving Glu(143), the mercaptoacyl group of the inhibitor, and the Zn ion could be considered a "modified" transition state mimic of the peptide bond hydrolysis. Due to the presence of the hindering (5-phenyl)proline, the inhibitor HS-CH(CH(2)Ph)CO-Gly-(5-Ph)Pro (2) interacts through the usual Zn monodentation via the thiol group and occupancy of S(1)' and S(2)' subsites by the aromatic moieties, the proline ring being outside the active site. The inhibitory potencies are consistent with these structural data, with higher affinities for 3 (4.2 x 10(-)(8) M) and 4 (4.8 x 10(-)(8) M) than for 2 (1.2 x 10(-)(6) M). The extension of the results, obtained with thermolysin being considered as the model of physiological zinc metallopeptidases, allows inhibitor-recognition modes for other peptidases, such as angiotensin converting enzyme and neutral endopeptidase, to be proposed and opens interesting possibilities for the design of new classes of inhibitors.     

Diadenosine 5',5"'-P1,P4-tetraphosphate and related adenylylated nucleotides in Salmonella typhimurium

Salmonella typhimurium LT2 rapidly accumulates high levels of a family of five adenylylated nucleotides following exposure to a bacteriostatic quinone, 6-amino-7-chloro-5,8-dioxoquinoline. These compounds have been analyzed using our recently described two-dimensional thin layer chromatographic method. The five dinucleotides, which cannot be detected in exponentially growing cells, have been identified as diadenosine 5',5"'-P1,P4-tetraphosphate (AppppA), ApppGpp (guanosine 3'-diphosphate-5'-adenosine-5'-(P1,P3-triphosphate)), AppppG (adenosine 5'-guanosine-5'-(P1,P4-tetraphosphate)), ApppG (adenosine 5'-guanosine-5'-(P1,P3-triphosphate)), and ApppA (diadenosine 5',5"'-P1,P3-triphosphate). AppppA has been previously detected in vitro as an enzymatic product of aminoacyl-tRNA synthetases and in vivo at submicromolar levels in eucaryotic cells. The induced intracellular concentration of AppppA and the other adenylylated nucleotides in S. typhimurium is approximately 100-fold higher than that found in eucaryotic cells. We propose that these dinucleotides are alarmones, regulatory molecules signaling a particular metabolic stress.     

Benzofurans and another constituent from seeds of Styrax officinalis

The benzofuran constituents of the seeds of Styrax officinalis were investigated. From the hexane extract, two new constituents named 5-(3"benzoyloxypropyl)-7-methoxy-2-(3',4'-methylenedioxyphenyl)-benzofuran (5) and 4-[3"-(1c-methylbutanoyloxy)propyl]-2-methoxy-(3',4'-methylenedioxyphenyl)-1a, 5b-dihydrobenzo-[3,4]-cyclobutaoxirene (6) were isolated together with four known compounds, 5-[3"-(1c-methylbutanoyloxy)propyl]-7-methoxy-2-(3',4'-dimethoxyphenyl)-benzofuran (4), 5-[3"-(1c-methylbutanoyloxy)propyl]-7- methoxy-2-(3',4'-methylenedioxyphenyl)-benzofuran (3), 5-(3"-acetoxypropyl)-7-methoxy2-(3',4'-methylenedioxphenyl)-benzofuran (2) and 5-(3"-hydroxypropyl)-7-methoxy-2-(3',4'-met hylenedioxyphenyl)-benzofuran (1). Although the compounds 1, 2, and 3 have been isolated previously from the seeds of Styrax obassia, this is the first record of their isolation from seeds of Styrax officinalis. The structures of the isolated compounds were established by 1D- and 2D-NMR (HMBC, HMQC, COSY), FABMS and high-resolution ESI FTMS.     

Synthesis of dinucleoside polyphosphates catalyzed by firefly luciferase.

In the presence of ATP, luciferin (LH2), Mg2+ and pyrophosphatase, the firefly (Photinus pyralis) luciferase synthesizes diadenosine 5',5"'-P1,P4-tetraphosphate (Ap4A) through formation of the E-LH2-AMP complex and transfer of AMP to ATP. The maximum rate of the synthesis is observed at pH 5.7. The Km values for luciferin and ATP are 2-3 microM and 4 mM, respectively. The synthesis is strictly dependent upon luciferin and a divalent metal cation. Mg2+ can be substituted with Zn2+, Co2+ or Mn2+, which are about half as active as Mg2+, as well as with Ni2+, Cd2+ or Ca2+, which, at 5 mM concentration, are 12-20-fold less effective than Mg2+. ATP is the best substrate of the above reaction, but it can be substituted with adenosine 5'-tetraphosphate (p4A), dATP, and GTP, and thus the luciferase synthesizes the corresponding homo-dinucleoside polyphosphates:diadenosine 5',5"'-P1,P5-pentaphosphate (Ap5A), dideoxyadenosine 5',5"'-P1,P4-tetraphosphate (dAp4dA) and diguanosine 5',5"'-P1,P4-tetraphosphate (Gp4G). In standard reaction mixtures containing ATP and a different nucleotide (p4A, dATP, adenosine 5'-[alpha,beta-methylene]-triphosphate, (Ap[CH2]pp), (S')-adenosine-5'-[alpha-thio]triphosphate [Sp)ATP[alpha S]) and GTP], luciferase synthesizes, in addition to Ap4A, the corresponding hetero-dinucleoside polyphosphates, Ap5A, adenosine 5',5"'-P1,P4-tetraphosphodeoxyadenosine (Ap4dA), diadenosine 5',5"'-P1,P4-[alpha,beta-methylene] tetraphosphate (Ap[CH2]pppA), (Sp-diadenosine 5',5"'-P1,P4-[alpha-thio]tetraphosphate [Sp)Ap4A[alpha S]) and adenosine-5',5"'-P1,P4-tetraphosphoguanosine (Ap4G), respectively. Adenine nucleotides, with at least a 3-phosphate chain and with an intact alpha-phosphate, are the preferred substrates for the formation of the enzyme-nucleotidyl complex. Nucleotides best accepting AMP from the E-LH2-AMP complex are those which contain at least a 3-phosphate chain and an intact terminal pyrophosphate moiety. ADP or other NDP are poor adenylate acceptors as very little diadenosine 5',5"'-P1,P3-triphosphate (Ap3A) or adenosine-5',5"'-P1,P3-triphosphonucleosides (Ap3N) are formed. In the presence of NTP (excepting ATP), luciferase is able to split Ap4A, transferring the resulting adenylate to NTP, to form hetero-dinucleoside polyphosphates. In the presence of PPi, luciferase is also able to split Ap4A, yielding ATP. The cleavage of Ap4A in the presence of Pi or ADP takes place at a very low rate. The synthesis of dinucleoside polyphosphates, catalyzed by firefly luciferase, is compared with that catalyzed by aminoacyl-tRNA synthetases and Ap4A phosphorylase.     

Flavonoids from Lysidice rhodostegia Hance

A novel flavonoid named mopanolchin (1), together with seven known flavonoids, was isolated by various chromatographic techniques and spectroscopic methods from the EtOAc extract of the roots of Lysidice rhodostegia Hance. The structure of the new compound was elucidated as 1"-(4-hydroxy-3, 5-dimethoxy)phenyl-2"-hydroxymethyl-dioxino [4', 5',1", 2"]mopanol (1) on the basis of spectral analysis.The known compounds were identified as (-)-epicatechin-3-O-gallate (2), epicatechin (3), naringenin (4),eriodictyol (5), luteolin (6), 7, 3', 4'-trihydroxyflavone (7) and (-)-robinetinidol (8).