纳米金修饰的碳纤维超微电极在高浓度抗坏血酸体系中选择性测定多巴胺

将柠檬酸三钠与硼氢化钠还原氯金酸制备纳米金颗粒,采用一步恒电位沉积的方法在碳纤维超微电极上沉积纳米金颗粒,并对电极进行电化学表征。分别对100μmol/L DA、1mmol/L AA在该电极上修饰前后的电化学行为进行了研究,结果表明在浓度为1 mmol/L抗坏血酸共存下,DA的浓度(0. 1～10μmol/L)与氧化峰电流成正比,线性回归方程为Ip(μA)=200 c(μmol/L)+2×10~(-4),相关系数R~2=0. 9979,线性范围0. 1～10μmol/L,检出限为1. 28×10~(-2)μmol/L (S/N=3)。方法可用于较高浓度抗坏血酸共存下对多巴胺的选择性测定。     

新型1,2,4-三唑三氮烯衍生物的合成及其生物活性

以对氨基苯甲酸为原料,经多步反应合成了16个未见文献报道的1,2,4-三唑三氮烯衍生物.利用~1H NMR~,(13)C NMR和HRMS对标题化合的结构进行了表征.衍生物的细胞毒活性测试结果表明,2-[4-(3,3-二甲基三氮烯-1-基)苯基]-3-氨基-4-S-(4-氯基苄基)-1,2,4-三唑(6g)、2-[4-(3,3-二甲基三氮烯-1-基)苯基]-3-氨基-4-S-(2,4-二氯基苄基)-1,2,4-三唑(6h)、2-[4-(3,3-甲基苯甲基三氮烯-1-基)苯基]-3-氨基-4-S-苄基-1,2,4-三唑(6i)、2-[4-(3,3-甲基苯甲基三氮烯-1-基)苯基]-3-氨基-4-S-(4-甲基苄基)-1,2,4-三唑(6j)、2-[4-(3,3-甲基苯甲基三氮烯-1-基)苯基]-3-氨基-4-S-(4-甲氧基苄基)-1,2,4-三唑(6l)、2-[4-(3,3-甲基苯甲基三氮烯-1-基)苯基]-3-氨基-4-S-(2,4-二氯基苄基)-1,2,4-三唑(6p)对膀胱癌细胞具有较好的抑制作用,其IC50值分别为23.883,5.512,8.731,8.077,5.590和12.195μmol/L,化合物6h,6i,6j,6l对前列腺癌细胞具有较好的抑制作用,其IC50值分别为13.690,21.908,10.772和4.827μmol/L.     

1,3,4-噻二唑三氮烯化合物的合成和生物活性研究

利用拼接原理将药效基团三氮烯与1,3,4-噻二唑相拼接,合成了15个未见报道的1,3,4-噻二唑三氮烯类衍生物,并用核磁共振波谱(NMR)、红外光谱(IR)和高分辨质谱(HRMS)等方法确定化合物结构.通过以典型三氮烯药物达卡巴嗪(DTIC)和药物5-氟尿嘧啶(5-FU)作参照,对人食管癌细胞(EC109)、人胃癌细胞(MGC803)和人前列腺癌细胞(PC-3)做活性检测,结果显示部分化合物对人胃癌细胞(MGC803)的抑制作用强于达卡巴嗪(DTIC),其中2-(3-甲基苯胺基)-5-[4-(3,3-二甲基三氮烯-1-基)苯基]-1,3,4-噻二唑(8c),2-(2-甲氧基苯胺基)-5-[4-(3,3-二甲基三氮烯-1-基)苯基]-1,3,4-噻二唑(8f),2-(3,4-二氯苯胺基)-5-[4-(3,3-二甲基三氮烯-1-基)苯基]-1,3,4-噻二唑(8l)的IC_(50)值低于5-氟尿嘧啶,分别为5.3,6.5和6.3μmol/L;部分化合物对人前列腺癌细胞(PC-3)的抑制作用强于达卡巴嗪(DTIC),其中8l的IC_(50)值低于5-氟尿嘧啶,为13.5μmol/L.     

低价钛盐还原反应的研究——Ⅲ.2,2-二芳基-1,l,l-三氯乙烷与低价钛盐的反应

2,2-二芳基-1,1,1-三氯乙烷(1)与TiCl_4-Zn起脱氯还原重排反应生成1,2-二芳基乙烯(3)。与TiCl_4-Mg反应时,2,2-二(对甲苯基)-1,1,1-三氯乙烷和2,2-二(对乙氧苯基)-1,1,1-三氯乙烷(1c,1d)主要得到重排产物2,2-二芳基乙烯(3)和2,2-二芳基-1-氯乙烯(4),后者可能是由相应的2,2-二芳基-1,1-二氯乙烷(2)生成的。但2,2-二苯-1,1,1-三氯乙烷和2,2-二(对氯苯基)-1,1,1-三氯乙烷(1a,1b)与此试剂反应只生成还原产物2,2-二芳基-1,1-二氯乙烷(2a,2b)。     

1,3,4-噁二唑三氮烯衍生物的合成及生物活性测定

利用拼合原理,将具有生物活性的三氮烯结构与1,3,4-噁二唑结构相拼合,设计合成了11个未见报道的1,3,4-噁二唑三氮烯衍生物.所合成化合物经1H NMR,IR和HRMS得到表征.用四甲基偶氮唑盐(MTT)法法评价了该类化合物对胃癌细胞(MGC803)和前列腺癌细胞(PC-3)的抑制作用,结果显示化合物2-[4-(3,3-二甲基三氮烯-1-基)苯基]-5-(4-甲氧基苯基)-1,3,4-噁二唑(b4)、2-[4-(3,3-二甲基三氮烯-1-基)苯基]-5-(2-甲氧基苯基)-1,3,4-噁二唑(b9)、2-[4-(3,3-二甲基三氮烯-1-基)苯基]-5-(3,4-甲叉二氧基苯基)-1,3,4-噁二唑(b10)、2-[4-(3,3-二甲基三氮烯-1-基)苯基]-5-(吡啶-4-基)-1,3,4-噁二唑(b11)对前列腺癌细胞的抑制作用强于典型三氮烯药物达卡巴嗪(DTIC),其IC50值分别为74.145,87.790,87.327和104.875μmol/L,而对胃癌细胞则几乎没有抑制作用.采用微量肉汤稀释法测试了该类化合物对大肠埃希菌(E.coli.)和金黄葡萄球菌(S.aureus)的抑制作用,结果显示这类化合物对这两种细菌并没有表现出抑制作用.     

基于烯胺腈结构的吡喃香豆素并嘧啶类化合物的合成及抗肿瘤活性研究

吡喃香豆素是一类重要的天然产物,具有广泛的生物活性和药理作用,如抗肿瘤、抗菌、抗人类免疫缺陷病毒(HIV)、抗炎、抗氧化等.嘧啶是另一类重要的含氮杂环化合物,利用药物设计中的药效团拼合原则,如将吡喃香豆素和嘧啶结构进行拼合,有可能获得抗肿瘤活性更好的先导化合物.因此,首先以4-羟基香豆素、芳香醛、丙二腈为原料,4-二甲氨基吡啶(DMAP)为催化剂,通过多组分反应合成具有烯胺腈结构的吡喃香豆素,再与N,N-二甲基甲酰胺二甲缩醛(DMF-DMA)反应制备N,N-二甲基甲脒,最后与芳香胺通过Dimroth重排制备新型4-苯胺基取代吡喃香豆素并嘧啶类化合物,并通过熔点,IR,1H NMR,13C NMR,元素分析对目标产物的结构进行了表征,所得目标产物均未见文献报道.该方法具有反应时间短、反应条件温和、操作简单、产率高、无需柱色谱分离等优点.通过四甲基偶氮唑盐微量酶反应比色法(MTT)对目标产物抑制人宫颈癌细胞Hela和人急性早幼粒白血病细胞HL-60的活性进行了体外评价,结果表明:化合物4-(4'-溴苯胺基)-5-(2',3'-二氯苯基)-色烯[3',4':5,6]吡喃[2,3-d]嘧啶-6-酮(4k)和4-(4'-溴苯胺基)-5-(4'-硝基苯基)-色烯[3',4':5,6]吡喃[2,3-d]嘧啶-6-酮(4l)对HL-60具有较高活性,其IC50分别为(11.3±0.3)和(10.8±0.2)μmol/L;化合物4-(4'-氯苯胺基)-5-(3',4',5'-三甲氧苯基)-色烯[3',4':5,6]吡喃[2,3-d]嘧啶-6-酮(4g)和4-(3'-氯-4'-氟苯胺基)-5-(3',4',5'-三甲氧苯基)-色烯[3',4':5,6]吡喃[2,3-d]嘧啶-6-酮(4h)对Hela具有较高活性,其IC50分别为(9.2±0.6)和(8.5±0.2)μmol/L.     

低价钛盐还原反应的研究——Ⅲ.2,2-二芳基-1,1,1-三氯乙烷与低价钛盐的反应

2,2-二芳基-1,1,1-三氯乙烷(1)与TiCl₄-Zn起脱氯还原重排反应生成1,2-二芳基乙烯(3)。与TiCl₄-Mg反应时,2,2-二(对甲苯基)-1,1,1-三氯乙烷和2,2-二(对乙氧苯基)-1,1,1-三氯乙烷(1c,1d)主要得到重排产物2,2-二芳基乙烯(3)和2,2-二芳基-1-氯乙烯(4),后者可能是由相应的2,2-二芳基-1,1-二氯乙烷(2)生成的。但2,2-二苯-1,1,1-三氯乙烷和2,2-二(对氯苯基)-1,1,1-三氯乙烷(1a,1b)与此试剂反应只生成还原产物2,2-二芳基-1,1-二氯乙烷(2a,2b)。     

N-(5-对-氯苯氧甲基-1,3,4-噻二唑-2-基)-S-(4-苯基-5-苯氧甲基-1,2,4-三唑-3-基)乙酰胺的合成与表征

取代苯氧乙酰肼(1a～1c)与异硫氰酸芳基酯(2a～2d)反应得到酰基硫脲类化合物(3a～3l),经碱合环得到4-苯基-5-苯氧甲基-1,2,4-三唑-3-硫酮(4a～4l),然后再与N-(5-对氯苯氧甲基-1,3,4-噻二唑-2-基)氯乙酰胺(6)反应合成了化合物N-(5-对氯苯氧甲基-1,3,4-噻二唑-2-基)-S-(4-苯基-5-苯氧甲基-1,2,4-三唑-3-基)乙酰胺(7a～7l)。所有化合物结构经元素分析、IR、1HNMR和MS确证。测定了化合物4e的晶体结构,其属于三斜晶系,P-1空间群,晶胞参数a=7.123(4),b=9.786(5),c=11.543(6),α=70.846(7)°,β=80.089(9)°,γ=89.922(11)°,V=747.5(7)3,Dc=1.345g/cm3,Z=2,F(000)=310,μ=0.218mm-1,R=0.0913,wR=0.2622     

4-(甲氧基噻吩基)-3-(取代苯甲酰基)-吡咯类化合物的合成与抗肿瘤活性研究

分别以2-甲氧基噻吩、3-甲氧基噻吩、3,4-二溴噻吩和取代苯乙酮为原料,经过溴甲氧基取代反应、VilsmeierHack反应、羟醛缩合和Van Leusen吡咯合成法,设计并合成了33个未见文献报道的4-取代噻吩基吡咯类化合物.其结构均经~1H NMR,~(13)C NMR及HRMS确认,同时采用噻唑蓝(MTT)法测试了目标化合物对CHO、HCT-116、MGC80-3、SGC-7901以及HUVEC细胞增殖抑制活性.结果显示,部分化合对MGC80-3细胞有较强(IC_(50)≤20μml/L)或中等(20μmol/LIC_(50)≤50μmol/L)增殖抑制作用,其中[4-(3,4-二甲氧基噻吩-2-基)-1H-吡咯-3-基](4-苯基苯基)甲酮(4a-2)和[4-(3,4-二甲氧基噻吩-2-基)-1H-吡咯-3-基](3-溴苯基)甲酮(4a-7)的IC_(50)值分别为8.6和8.5μmol/L;化合物4a-7对HCT-116细胞有中等抑制活性;化合物4a-2和4a-7对SGC-7901细胞有中等增殖抑制活性;并且几乎所有化合物对正常人体细胞HUVEC无明显抑制作用.     

2-甲氧亚胺基-2-(多取代苯基)乙酸甲酯类化合物合成及杀菌活性

以取代甲苯为原料,与草酰氯单甲酯反应生成傅克酰基化产物2-羰基-2-(邻甲基苯基)乙酸甲酯(A),A与甲氧基胺盐酸盐反应得到(Z/E)-2-(甲氧亚胺基)-2-(邻甲基苯基)乙酸甲酯(B),B与溴单质反应得到中间体(Z/E)-2-(2-溴甲基)苯基-2-甲氧亚胺基乙酸甲酯(C).E-2-甲氧亚胺基-(2-溴甲基苯基)乙酸甲酯(E)用硝酸硝化得到中间体E-2-甲氧亚胺基-(2-溴甲基-5-硝基苯基)乙酸甲酯(F).中间体C和F与芳香酮肟经过缩合反应生成甲氧亚胺基-(4或5-取代基-2-(1-(3或4-取代苯基)-E-亚乙基胺氧甲基)苯基)乙酸甲酯化合物(D,E和G),H可以从G1还原得到.所得新化合物均通过1H NMR,13C NMR,19F NMR,IR和HRMS等确证.用生长速率法测试了目标化合物对黄瓜灰霉、番茄早疫、小麦赤霉、辣椒疫霉、油菜菌核和水稻纹枯等6种真菌的离体抑菌活性.结果表明,部分目标化合物比肟菌酯有更高的杀菌活性.     

Concerted rearrangement versus heterolytic cleavage in anionic [2,3]- and [3,3]-sigmatropic shifts. A DFT study of relationships among anion stabilities,mechanisms, and rates

The anionic [2,3] sigmatropic Wittig rearrangements of deprotonated 4-hetera-1-pentenes and the anionic [3,3] sigmatropic Cope rearrangements of 3-substituted-1,5-hexadienes were explored by using density functional theory calculations. While the deprotonated anionic 3-hydroxy-1,5 hexadiene (2a), 3-thiohydroxy-1,5-hexadiene (2c), and 3-formamidyl-1,5-hexadiene (2d) Cope substrates undergo concerted rearrangements, the deprotonated anionic 3-amino-1,5-hexadiene (2b) and 3-methyl-1,5-hexadiene (2e) Cope substrates follow nonconcerted cleavage/recombination pathways. We have also found that the gas-phase Wittig (1a), aza-Wittig (1b), and carba-Wittig (1c) reactions proceed via nonconcerted cleavage/recombination pathways. These results are compared with previous results on the Cope rearrangements of deprotonated anionic 3-hydroxy-1,5-hexadiene and 3-amino-1,5-hexadiene anions. A previously established model that heterolytic and homolytic bond dissociation energies can be used to predict how anionic amino- and oxy-Cope substrates will react is generalized to account for the reactivity of other Cope substrates as well as for the Wittig rearrangements. There is also a relationship between the basicity of the anionic substituent in the Cope rearrangement and the reaction pathway: the more basic the substituent anion, the less stable it is, and the more likely it is that cleavage will occur. A first step toward studying these reactions in solution was also taken by calculating energetics for some of the rearrangements with a lithium counterion present.     

A Convenient Method for the Synthesis of (3S, 4R)-3-p-Methoxyphenyl-4-hydroxy-1,5-hexadiene

A new procedure for the synthesis of (3S, 4R)-3-p-methoxyphenyl-4-hydroxy-1,5-hexadiene is described using D-mannitol as chiral source.     

Chiral Cyclopentane-Based Mimics of D-myo-Inositol 1,4,5-Trisphosphate from D-Glucose

Two routes from D-glucose to chiral, ring-contracted analogs of the second messenger D-myo-inositol 1,4,5-trisphosphate are described. Methyl alpha-D-glucopyranoside was converted by an improved procedure into methyl 4,6-O-(p-methoxybenzylidene)-alpha-D-glucopyranoside (6) and thence into methyl 2-O-benzyl-3,4-bis-O-(p-methoxybenzyl)-alpha-D-gluco-hexodialdopyranoside (1,5) (14) in four steps. In the first ring-contraction method 14 was converted into methyl 2-O-benzyl-6,7-dideoxy-3,4-bis-O-(p-methoxybenzyl)-alpha-D-gluco-hept-6-enopyranoside (1,5) (15), which on sequential treatment with Cp(2)Zr(n-Bu)(2) followed by BF(3).Et(2)O afforded a mixture of (1R,2S,3S,4R,5S)-3-(benzyloxy)-4-hydroxy-1,2-bis[(p-methoxybenzyl)oxy]-5-vinylcyclopentane (16) and its 4S,5R diastereoisomer 17. Removal of the p-methoxybenzyl groups of 16 and subsequent phosphorylation and deprotection afforded the first target compound, (1R,2R,3S,4R,5S)-3-hydroxy-1,2,4-tris(phosphonooxy)-5-vinylcyclopentane (3). In the second route, intermediate 14 was subjected to SmI(2)-mediated ring contraction to give (1R,2S,3S,4R,5S)-3-(benzyloxy)-4-hydroxy-5-(hydroxymethyl)-1,2-bis[(p-methoxybenzyl)oxy]cyclopentane (20). Benzylation of 20 provided (1R,2S,3S,4R,5S)-3-(benzyloxy)-6-[(benzyloxy)methyl]-4-hydroxy-1,2-bis[(p-methoxybenzyl)oxy]cyclopentane (22) and (1R,2S,3S,4R,5S)-3,4-bis(benzyloxy)-5-(hydroxymethyl)-1,2-bis[(p-methoxybenzyl)oxy]cyclopentane (21), which were elaborated to the target trisphosphates (1R,2R,3S,4R,5S)-3-hydroxy-5-(hydroxymethyl)-1,2,4-tris(phosphonooxy)cyclopentane (4) and (1R,2S,3R,4R,5S)-1,2-dihydroxy-3,4-bis(phosphonooxy)-5-[(phosphonooxy)methyl]cyclopentane (5), respectively. Both 3 and 4 mobilized intracellular Ca(2+), but 4 was only a few fold less potent than D-myo-inositol 1,4,5-trisphosphate, demonstrating that effective mimics can be designed that do not bear a six-membered ring.     

Integration of catalysis and analysis is the key: rapid and precise investigation of the catalytic asymmetric Gosteli-Claisen rearrangement

The kinetics of the Cu(II)(bisoxazoline)-catalyzed diastereo- and enantioselective Gosteli-Claisen rearrangement of 2-alkoxycarbonyl-substituted allyl vinyl ethers has been investigated by enantioselective on-column reaction gas chromatography (ocRGC). Enantioselective ocRGC integrates (stereoselective) catalysis and enantioselective chromatography in a single microcapillary, which is installed in a GC-MS for direct analysis of conversion and selectivity. Thus, this technique allows direct differentiation of thermal and stereoselectively catalyzed reaction pathways and determination of activation parameters and selectivities of the individual reaction pathways starting from stereoisomeric reactants with high precision. Two modes of operation of enantioselective ocRGC are presented to investigate noncatalyzed, i.e., conversion of isopropyl-2-(allyloxy)but-2Z-enoate 1 to isopropyl-3R,S-methyl-2-oxy-hex-5-enoate (±)-2 and the [Cu{(R,R)-Ph-box}](SbF(6))(2)-catalyzed Gosteli-Claisen rearrangement, i.e., conversion of isopropyl-2-(but-2'E-en-1-yloxy)but-2Z-enoate (E,Z)-3 to isopropyl-3S,4S-dimethyl-2-oxy-hex-5-enoate 4b. Eyring activation parameters have been determined by temperature-dependent measurements: Uncatalyzed rearrangement of 1 to (±)-2 gives ΔG(?) (298 K) = 114.1 ± 0.2 kJ·mol(-1), ΔH(?) = 101.1 ± 1.9 kJ·mol(-1), and ΔS(?) = -44 ± 5 J·(K·mol)(-1), and catalyzed rearrangement of (E,Z)-3 to 4b gives ΔG(?)(298 K) = 101.1 ± 0.3 kJ·mol(-1), ΔH(?) = 106.1 ± 6.6 kJ·mol(-1), and ΔS(?) = 17 ± 19 J·(K·mol)(-1).     

Studies on the constituents of Broussonetia species VIII. Four new pyrrolidine alkaloids, broussonetines R, S, T, and V and a new pyrroline alkaloid, broussonetine U, from Broussonetia kazinoki Sieb

Four new pyrrolidine alkaloids, broussonetines R, S, T, and V and a new pyrroline alkaloid, broussonetine U were isolated from the branches of Broussonetia kazinoki SIEB. (Moraceae) in low yield. Broussonetines R, S and T were formulated as (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(1R)-1-hydroxy-3-[6-(4-hydroxybutyl)-cyclohexy-2-on-1(6)-enyllpropyl] pyrrolidine (1), (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(1R,10S)-1,10,13-trihydroxytridecyl] pyrrolidine (2), (2R,3R,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(1R,5S)-1,5, 13-trihydroxy-10-oxo-tridecyl] pyrrolidine (3). And broussonetines U and V were proposed to be (2S,3S,4S)-2-hydroxymethyl-3, 4-dihydroxy-5-(9-oxo-13-hydroxytridecyl)-5-pyrroline (4), (2R,3S,4R,5R)-2-hydroxymethyl-3,4-dihydroxy-5-[(E)-9-oxo-13-hydroxy-3-tridecenyl] pyrrolidine (5), respectively, by spectroscopic and chemical methods.     

Five new nortropane alkaloids and six new amino acids from the fruit of Morus alba LINNE growing in Turkey

Investigation of the constituents of the fruits of Morus alba LINNE (Moraceae) afforded five new nortropane alkaloids (1-5) along with nor-psi-tropine (6) and six new amino acids, morusimic acids A-F (7-12). The structures of the new compounds were determined to be 2alpha,3beta-dihydroxynortropane (1), 2beta,3beta-dihydroxynortropane (2), 2alpha,3beta,6exo-trihydroxynortropane (3), 2alpha,3beta,4alpha-rihydroxynortropane (4), 3beta,6exo-dihydroxynortropane (5), (3R)-3-hydroxy-12-[(1S,4S)-4-[(1S)-1-hydroxyethyl]-pyrrolidin-1-yll-dodecanoic acid-3-O-beta-D-glucopyranoside (7), (3R)-3-hydroxy-12-[(1S,4S)-4-[(1S)-1-hydroxyethyl]-pyrrolidin-1-yll-dodecanoic acid (8), (3R)-3-hydroxy-12-1(1R,4R,5S)-4-hydroxy-5-methyl-piperidin-1-yll-dodecanoic acid-3-O-beta-D-glucopyranoside (9), (3R)-3-hydroxy-12-[(1R,4R,5S)-4-hydroxy-5-methyl-piperidin-1-yll-dodecanoic acid (10), (3R)-3-hydroxy-12-[(1R,4R,5S)-4-hydroxy-5-hydroxymethyl-piperidin-1-yl]-dodecanoic acid-3-O-beta-D-glucopyranoside (11), and (3R)-3-hydroxy-12-[(1R,4S,5S)-4-hydroxy-5-methyl-piperidin-1-yl]-dodecanoic acid (12) on the basis of spectral and chemical data.     

Synthesis and Crystal Structure of 1-（4-Fluorophenyl）-2-hexylthiobenzo[4,5]-furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5（1H）-one

The crystal structure of the title compound 1-(4-fluorophenyl) -2-hexylthio-benzo [4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5(1H) -one(C23H21FN4O2S,Mr = 436.5) has been prepared and determined by single-crystal X-ray diffraction. The crystal is of monoclinic,space group P21/n with a = 13.9854(3) ,b = 17.2678(4) ,c = 18.1828(5) ,β = 99.364(2) °,V = 4332.58(18) 3,Z = 4,Dc = 1.338,F(000) =1824,μ = 0.185 mm-1,MoKa radiation(λ = 0.71073) ,R = 0.0538 and wR = 0.1162 for 4728 observed reflections with I > 2σ(I) . X-ray diffraction analysis reveals the fused rings of benzo[4,5]furo[3,2-d]-1,2,4-triazolo[1,5-a] pyrimidin-5(1H) -one system are nearly coplanar. The crystal packing is mainly stabilized by weak intermolecular C-H···O hydrogen bond and π-π interactions.     

培养南海红树林内源真菌Fusarium sp. ZZF60产新型蒽醌衍生物

通过人工发酵培养,从南海红树林内源真菌Fusarium sp.ZZF60的培养液中分离得到:1种新蒽醌衍生物,6,8-二甲氧基-1-甲基-2-(3-氧丁基)蒽醌(1),以及5种已知化合物:7-羟基-3-(4-甲氧基苯基)苯并-γ-吡喃酮(2),2,4-二羟基-6-[(1′E,3′E)-1′,3′-戊二烯基]苯甲醛(3),(E)-4-羟基肉桂酸甲酯(4),4-(4-羟基苯基)-2-丁醇(5),4-羟基苯甲酸(6)。它们的结构通过MS、NMR等波谱分析推导确定。初步药理活性显示,化合物1抑制体外培养人喉癌细胞Hep2和人肝癌细胞HepG2的IC50分别为16和23μmol/L。     

Formation and structure elucidation of two novel spiro[2H-indol]-3(1H)-ones

The molecular structures of two byproducts 1,1'-diphenyl-3',4'-dihydrodispiro[indole-2,2'-furan-5',2'-indole]-3,3'(1H, 1'H)-dione (3) and 1,5'-diphenyl-4',5'-dihydro-3'H-spiro[indole-2,2'-pyrano[3,2-b]indol]-3(1H)-one (4), which accompanied the rearrangement of 3-hydroxy-3-methyl-1-phenylquinoline-2,4(1H,3H)-dione (1) to 2-hydroxy-2-methyl-1-phenyl-1,2-dihydro-3H-indol-3-one (2), have been elucidated by NMR, MS, and X-ray diffraction.     

Re-examining the Mechanisms of Competing Pericyclic Reactions of 1,3,7-Octatriene

DFT (both B3LYP and M06-2X), CASSCF, and CASPT2 calculations were used to investigate competing [3,?3] and [3,?5] sigmatropic shifts and intramolecular [4+2] cycloaddition of 1,3,7-octatriene. In accord with previous results on 1,5-hexadiene, CASSCF calculations found both stepwise and concerted pathways for the [3,?3] rearrangement. For the competing [3,?5] sigmatropic rearrangement, CASSCF and CASPT2 calculations revealed three stepwise pathways with similar barriers. UB3LYP and UM06-2X calculations predicted a different potential energy landscape: no stepwise [3,?3] pathway, only two competing [3,?5] sigmatropic shifts, and an intramolecular Diels-Alder cycloaddition/homolytic ring-opening pathway. Significant lowering of barriers for all rearrangements was predicted for some 1,3,7-octatrienes with substituents at the 4- and 7-positions.