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1.
Chirality ; 34(10): 1320-1327, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35775430

RESUMO

Chiral high-performance liquid chromatography (HPLC) analysis of natural pericosine A, which appeared in literature first in 1977, from Periconia byssoides was conducted using a column CHIRALPAK® AD-H to determine the enantiomeric composition of the original mixture which was found to be 68: 32 mixtures of (+)- and (-)-enantiomer, respectively. Furthermore, two independently isolated samples of pericosine A from the same fungus were also analyzed to show the two peaks in the HPLC charts at approximate 1:1 ratio. These results concluded that pericosine A derived from Periconia byssoides was indeed an enantiomeric mixture. Synthesized enantiomers were subjected to evaluation of antitumor activity against three kinds of tumor cells (p388, L1210, HL-60), indicating moderate cytotoxicity against all three kinds of tumor cell lines, but significant difference in potency between the enantiomers was not observed. In contrast, when both the enantiomers of pericosine A were evaluated against five kinds of glycosidases-inhibitory activities (α- and ß-glucosidases, α- and ß-galactosidases, and α-mannosidase), an apparent difference on anti-glycosidase assay was found between the enantiomers: (-)-pericosine A inhibited α-glucosidase at IC50 : 2.25 mM, and ß-galactosidase at IC50 : 5.38 mM, albeit the (+)-enantiomer showed inactivity against these five enzymes.


Assuntos
Ascomicetos , Ascomicetos/química , Cromatografia Líquida de Alta Pressão/métodos , Ácido Chiquímico/análogos & derivados , Ácido Chiquímico/química , Estereoisomerismo
2.
Inorg Chem ; 61(31): 12155-12164, 2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35876345

RESUMO

Tetrazolato-bridged dinuclear platinum(II) complexes ([{cis-Pt(NH3)2}2(µ-OH)(µ-5-R-tetrazolato-N2,N3)]2+; tetrazolato-bridged complexes) show remarkable cytotoxic effects in vitro and antitumor activity in vivo. Here, we examined the structure-activity relationship of a series of fluorine-containing derivatives (R = CFH2, CF2H, or CF3), focusing on their lipophilicity, cellular accumulation, cytotoxicity, interactions with a nucleobase and double-stranded deoxyribonucleic acid, and in vivo antitumor efficacy. Fluorination had a little effect on the properties of the derivatives in vitro; however, marked differences in in vitro cytotoxicity and in vivo tumor growth inhibition activity were observed. In BALB/c mice bearing colon-26 tumors, the antitumor efficacies of the derivatives were markedly altered, even by changing the number of fluorine atoms by one. In addition, one derivative, [{cis-Pt(NH3)2}2(µ-OH)(µ-5-difluoromethyltetrazolato-N2,N3)](NO3)2, showed a significantly higher antitumor efficacy compared with oxaliplatin, a current first-line drug and the only platinum-based drug approved for the treatment of colon cancer. Together, the present results indicate that introducing fluorine into tetrazolato-bridged complexes may be useful for modulating in vivo activities.


Assuntos
Antineoplásicos , Platina , Animais , Antineoplásicos/farmacologia , Cisplatino/farmacologia , Flúor , Camundongos , Compostos Organoplatínicos/farmacologia , Platina/farmacologia , Tetrazóis/farmacologia
3.
Mar Drugs ; 20(7)2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35877731

RESUMO

The enantiomers of 6-fluoro-, 6-bromo-, and 6-iodopericosine A were synthesized. An efficient synthesis of both enantiomers of pericoxide via 6-bromopericosine A was also developed. These 6-halo-substituted pericosine A derivatives were evaluated in terms of their antitumor activity against three types of tumor cells (p388, L1210, and HL-60) and glycosidase inhibitory activity. The bromo- and iodo-congeners exhibited moderate antitumor activity similar to pericosine A against the three types of tumor cell lines studied. The fluorinated compound was less active than the others, including pericosine A. In the antitumor assay, no significant difference in potency between the enantiomers was observed for any of the halogenated compounds. Meanwhile, the (-)-6-fluoro- and (-)-6-bromo-congeners inhibited α-glucosidase to a greater extent than those of their corresponding (+)-enantiomers, whereas (+)-iodopericosine A showed increased activity when compared to its (-)-enantiomer.


Assuntos
Antineoplásicos , Ácido Chiquímico , Antineoplásicos/farmacologia , Ácido Chiquímico/análogos & derivados , Relação Estrutura-Atividade , alfa-Glucosidases
4.
Data Brief ; 40: 107697, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34993284

RESUMO

In this data file, the synthetic procedures for the preparation of a series of anticancer tetrazolato-bridged dinuclear platinum(II) complexes ([{cis-Pt(NH3)2}2(µ-OH)(µ-5-R-tetrazolato-N2,N3)]n+ (n = 1 or 2, tetrazolato-bridged complexes)) and of the bridging ligands of 5-substituted 1H-tetrazoles (5-R-1H-tetrazoles) are described. These compounds were characterized by 1H-, 13C-, 19F- and 195Pt-NMR spectroscopy and mass spectrometry.

5.
Molecules ; 26(11)2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199652

RESUMO

The direct 4-alkoxylation of 4-iodo-1H-pyrazoles with alcohols was achieved by a CuI-catalyzed coupling protocol. The optimal reaction conditions employed excess alcohol and potassium t-butoxide (2 equiv) in the presence of CuI (20 mol%) and 3,4,7,8-tetramethyl-1,10-phenanthroline (20 mol%) at 130 °C for 1 h under microwave irradiation. The present method was efficiently applied to the synthesis of withasomnine and its six- and seven-membered cyclic homologs.

6.
Molecules ; 25(20)2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-33053697

RESUMO

Alkylamino coupling reactions at the C4 positions of 4-halo-1H-1-tritylpyrazoles were investigated using palladium or copper catalysts. The Pd(dba)2 catalyzed C-N coupling reaction of aryl- or alkylamines, lacking a ß-hydrogen atom, proceeded smoothly using tBuDavePhos as a ligand. As a substrate, 4-Bromo-1-tritylpyrazole was more effective than 4-iodo or chloro-1-tritylpyrazoles. Meanwhile, the CuI mediated C-N coupling reactions of 4-iodo-1H-1-tritylpyrazole were effective for alkylamines possessing a ß-hydrogen atom.


Assuntos
Cobre/química , Paládio/química , Pirazóis/química , Catálise
7.
Mar Drugs ; 18(4)2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-32326065

RESUMO

Inspired by the significant -glucosidase inhibitory activities of (+)- and (-)-pericosine E, we herein designed and synthesized 16 analogs of these marine natural products bearing a methoxy group instead of a chlorine atom at C6. Four of these compounds exhibited moderate -glucosidase inhibitory activities, which were weaker than those of the corresponding chlorine-containing species. The four compounds could be prepared by coupling reactions utilizing the (-)-pericosine B moiety. An additional in silico docking simulation suggested that the reason of reduced activity of the C6-methoxylated analogs might be an absence of hydrogen bonding between a methoxy group with the surrounding amino acid residues in the active site in -glucosidase.


Assuntos
Inibidores de Glicosídeo Hidrolases/análise , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/síntese química , Ácido Chiquímico/análogos & derivados , Simulação por Computador , Ligantes , Simulação de Acoplamento Molecular , Estrutura Molecular , Ácido Chiquímico/química , Relação Estrutura-Atividade , alfa-Glucosidases
8.
Chem Pharm Bull (Tokyo) ; 68(1): 1-33, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31902899

RESUMO

Novel reactions using hetero-heavy atoms (P, S, Si, Se, and Sn) were developed and applied to the synthesis of biofunctional molecules and some medicine-candidates, in which the following items are covered. 1) Development of introduction of C1-unit using cyanophosphates (CPs). 2) Carbene-generation under neutral condition from CPs and its application to organic synthesis. 3) [3,3]Sigmatropic rearrangement-ring expansion reactions of medium-sized cyclic thionocarbonates containing a sulfur atom and their application to natural product synthesis. 4) Stereoselective synthesis of novel ß-imidazole C-nucleosides via diazafulvene intermediates and their application to investigating ribozyme reaction mechanism. 5) Developments of novel histamine H3- and H4-receptor ligands using new synthetic methods involving Se or Sn atoms.


Assuntos
Produtos Biológicos/química , Metais/química , Animais , Produtos Biológicos/síntese química , Proliferação de Células/efeitos dos fármacos , Agonistas dos Receptores Histamínicos/síntese química , Agonistas dos Receptores Histamínicos/química , Agonistas dos Receptores Histamínicos/farmacologia , Antagonistas dos Receptores Histamínicos/síntese química , Antagonistas dos Receptores Histamínicos/química , Antagonistas dos Receptores Histamínicos/farmacologia , Humanos , Metano/análogos & derivados , Metano/química , Metano/metabolismo , Nitrilas/química , Nucleosídeos/síntese química , Nucleosídeos/química
9.
Molecules ; 24(2)2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30650589

RESUMO

Three types of pyrazole-fused heterobicycles, i.e., 1,5-, 1,7-, and 2,5-dihydropyrano[3,2-c]pyrazoles, were synthesized from 4-allyloxy-1H-pyrazoles. A sequence of the Claisen rearrangement of 4-allyloxy-1H-pyrazoles, ruthenium-hydride-catalyzed double bond migration, O-allylation, and ring-closing metathesis was employed in this study.


Assuntos
Técnicas de Química Sintética , Pirazóis/síntese química , Catálise , Estrutura Molecular , Pirazóis/química , Rutênio/química
10.
J Inorg Biochem ; 192: 82-86, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30612029

RESUMO

We synthesized and characterized 15 new derivatives of the highly anticancer-active platinum(II) complex [{cis-Pt(NH3)2}2(µ-OH)(µ-tetrazolato-N2,N3)]2+ (5-H-Y) by making substitutions at tetrazole C5. We then evaluated the comprehensive structure-cytotoxicity relationships of a total of 23 derivatives in two murine lymphocytic leukaemia cell lines, sensitive and resistant to cisplatin. We also report the in vivo antitumor efficacy of three ester derivatives, two of which exhibited much higher efficacy than oxaliplatin against mouse homografted Colon-26 colorectal tumor.


Assuntos
Neoplasias Colorretais , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Compostos Organoplatínicos , Tetrazóis , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Cisplatino/química , Cisplatino/farmacocinética , Cisplatino/farmacologia , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Camundongos , Camundongos Endogâmicos BALB C , Compostos Organoplatínicos/síntese química , Compostos Organoplatínicos/química , Compostos Organoplatínicos/farmacocinética , Compostos Organoplatínicos/farmacologia , Oxaliplatina/química , Oxaliplatina/farmacocinética , Oxaliplatina/farmacologia , Relação Estrutura-Atividade , Tetrazóis/química , Tetrazóis/farmacocinética , Tetrazóis/farmacologia
11.
Molecules ; 23(3)2018 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-29509713

RESUMO

Synthesis of novel pyrazole-fused heterocycles, i.e., dihydro-1H- or 2H-oxepino[3,2-c]pyrazoles (6 or 7) from 4-allyloxy-1H-pyrazoles (1) via combination of Claisen rearrangement and ring-closing metathesis (RCM) has been achieved. A suitable catalyst for the RCM of 5-allyl-4-allyloxy-1H-pyrazoles (4) was proved to be the Grubbs second generation catalyst (Grubbs2nd) to give the predicted RCM product at room temperature in three hours. The same reactions of the regioisomer, 3-allyl-4-allyloxy-1H-pyrazoles (5), also proceeded to give the corresponding RCM products. On the other hand, microwave aided RCM at 140 °C on both of 4 and 5 afforded mixtures of isomeric products with double bond rearrangement from normal RCM products in spite of remarkable reduction of the reaction time to 10 min.


Assuntos
Pirazóis/síntese química , Etil-Éteres/química , Pirazóis/química
12.
J Org Chem ; 82(11): 5538-5556, 2017 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-28470066

RESUMO

Cyanophosphates (CPs) can be easily prepared from either ketones or aldehydes, and their reaction with NaN3-Et3N·HCl results in the formation of azidotetrazoles. Under microwave irradiation, successive fragmentation of the azidotetrazoles generates alkylidene carbenes that undergo [1,2]-rearrangement and are transformed into homologous alkynes. Treatment of ketone-derived CPs with TMSN3 and Bu2SnO as catalyst in toluene at reflux directly yields the corresponding internal alkynes, whereas the reaction of aldehyde-derived CPs with NaN3-Et3N·HCl in THF at reflux or TMSN3-Bu2SnO (cat.) in toluene at reflux provides homologous terminal alkynes in good yields. These reactions take place under neutral conditions and can be successfully extended to obtain alkynes that are not usually accessible from the corresponding carbonyl compounds by the Ohira-Bestmann or Shioiri procedures, which require basic conditions.

13.
Mar Drugs ; 15(1)2017 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-28124983

RESUMO

Pericosine E (6), a metabolite of Periconia byssoides OUPS-N133 was originally isolated from the sea hare Aplysia kurodai, which exists as an enantiomeric mixture in nature. The enantiospecific syntheses of both enantiomers of Periconia byssoides OUPS-N133 has been achieved, along with six stereoisomers, using a common simple synthetic strategy. For these efficient syntheses, highly regio- and steroselective processes for the preparation of bromohydrin and anti-epoxide intermediates were applied. In order to access the unique O-linked carbadisaccharide structure, coupling of chlorohydrin as a donor and anti-epoxide as an acceptor was achieved using catalytic BF3·Et2O. Most of the synthesized compounds exhibited selectively significant inhibitory activity against α-glycosidase derived from yeast. The strongest analog showed almost 50 times the activity of the positive control, deoxynojirimycin.


Assuntos
Dissacarídeos/química , Inibidores de Glicosídeo Hidrolases/química , Ácido Chiquímico/análogos & derivados , alfa-Glucosidases/química , 1-Desoxinojirimicina/química , Álcoois/química , Ascomicetos/química , Cloridrinas/química , Compostos de Epóxi/química , Glucosamina/análogos & derivados , Glucosamina/química , Ácido Chiquímico/química , Estereoisomerismo , Leveduras/química
14.
Inorg Chem ; 56(2): 802-811, 2017 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-28045514

RESUMO

Derivatives of the highly antitumor-active compound [{cis-Pt(NH3)2}2(µ-OH)(µ-tetrazolato-N2,N3)]2+ (5-H-Y), which is a tetrazolato-bridged dinuclear platinum(II) complex, were prepared by substituting a linear alkyl chain moiety at C5 of the tetrazolate ring. The general formula for the derivatives is [{cis-Pt(NH3)2}2(µ-OH)(µ-5-R-tetrazolato-N2,N3)]2+, where R is (CH2)nCH3 and n = 0 to 8 (complexes 1-9). The cytotoxicity of complexes 1-4 in NCI-H460 human non-small-cell lung cancer cells decreased with increasing alkyl chain length, and those of complexes 5-9 increased with increasing alkyl chain length. That is, the in vitro cytotoxicity of complexes 1-9 was found to have a U-shaped association with alkyl chain length. This U-shaped association is attributable to the degree of intracellular accumulation. Although circular dichroism spectroscopic measurement indicated that complexes 1-9 induced comparable conformational changes in the secondary structure of DNA, the tetrazolato-bridged complexes induced different degrees of DNA compaction as revealed by a single DNA measurement with fluorescence microsopy, which also had a U-shaped association with alkyl chain length that matched the association observed for cytotoxicity. Complexes 7-9, which had alkyl chains long enough to confer surfactant-like properties to the complex, induced DNA compaction 20 or 1000 times more efficiently than 5-H-Y or spermidine. A single DNA measurement with transmission electron microscopy revealed that complex 8 formed large spherical self-assembled structures that induced DNA compaction with extremely high efficiency. This result suggests that these structures may play a role in the DNA compaction that was induced by the complexes with the longer alkyl chains. The derivatization with a linear alkyl chain produced a series of complexes with unique cellular accumulation and DNA conformational change profiles and a potentially useful means of developing next-generation platinum-based anticancer drugs. In addition, the markedly high ability of these complexes to induce DNA compaction and their high intracellular accumulation emphasized the difference in mechanism of action from platinum-based anticancer drugs.


Assuntos
Antineoplásicos/farmacologia , DNA/química , Compostos Organoplatínicos/farmacologia , Tetrazóis/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Linhagem Celular Tumoral , Cisplatino/farmacologia , Humanos , Estrutura Molecular , Conformação de Ácido Nucleico , Compostos Organoplatínicos/síntese química , Compostos Organoplatínicos/química , Espermidina/farmacologia , Relação Estrutura-Atividade , Tensoativos/síntese química , Tensoativos/química , Tensoativos/farmacologia , Tetrazóis/síntese química , Tetrazóis/química
15.
Biochem Biophys Res Commun ; 480(3): 479-485, 2016 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-27773822

RESUMO

Histamine is involved in various physiological functions, including its neurotransmitter actions in the central nervous system and its action as a causative agent of inflammation, allergic reactions, and gastric acid secretions. Histamine expression and biosynthesis have been detected in breast cancer cells. It was recently suggested that the histamine H3 receptor (H3R) plays a role in the proliferation of breast cancer cells. We recently developed the non-imidazole H3R antagonist OUP-186 which exhibited a potent and selective human H3R antagonistic activity as well as no activity against the human histamine H4 receptor (H4R). In this study, we compared the effects of OUP-186 on the proliferation of estrogen receptor negative (ER-) breast cancer cells (MDA-MB-231) and ER+ breast cancer cells (MCF7) to the effects of clobenpropit (potent imidazole-containing H3R antagonist). OUP-186 and clobenpropit suppressed the proliferation of breast cancer cells. The IC50 values at 48 h for OUP-186 and clobenpropit were approximately 10 µM and 50 µM, respectively. Furthermore, OUP-186 potently induced cell death by activating caspase-3/7, whereas cell death was only slightly induced by clobenpropit. In addition, OUP-186 treatment blocked the proliferation increase triggered by 100 µM (R)-(-)-α-methylhistamine (H3R agonist). The use of 4-methylhistamine (H4R agonist) and JNJ10191584 (selective H4R antagonist) did not affect breast cancer proliferation. These results indicate that OUP-186 potently suppresses proliferation and induces caspase-dependent apoptotic death in both ER+ and ER-breast cancer cells.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Antagonistas dos Receptores Histamínicos H3/administração & dosagem , Antineoplásicos/administração & dosagem , Neoplasias da Mama/metabolismo , Linhagem Celular Tumoral , Células Cultivadas , Relação Dose-Resposta a Droga , Humanos , Dose Letal Mediana , Células MCF-7
16.
Yakugaku Zasshi ; 136(9): 1217-32, 2016.
Artigo em Japonês | MEDLINE | ID: mdl-27592826

RESUMO

S-Alkyl-N-alkylisothiourea compounds, which contain various cyclic amines, were synthesized using 3-phenylpropionyl isothiocyanate (PPI) to discover novel non-imidazole histamine H3 receptor (H3R) antagonists. The synthetic route was improved remarkably by using 2-nitrophenylacetyl isothiocyanate (NPAI). Among the synthesized compounds, N-[4-(4-chlorophenyl)butyl]-S-[3-piperidin-1-yl)propyl]isothiourea (1k, OUP-186) exhibited potent and selective antagonism against human H3R but not human H4R, in vitro. Of particular interest, they did not show antagonism for the histamine release in rat brain microdialysis in vivo, suggesting species-selective differences in antagonist affinities. Furthermore, in silico docking studies of OUP-186 and its C2-homolog (OUP-181) in human/rat H3Rs suggested that the structural difference of antagonist-docking sites between human and rat H3Rs was attributable to the Ala122/Val122 mutation.


Assuntos
Descoberta de Drogas , Antagonistas dos Receptores Histamínicos H3/síntese química , Tioureia/análogos & derivados , Tioureia/síntese química , Animais , Encéfalo/metabolismo , Antagonistas dos Receptores Histamínicos H3/química , Antagonistas dos Receptores Histamínicos H3/farmacologia , Liberação de Histamina/efeitos dos fármacos , Humanos , Mutação , Ratos , Receptores Acoplados a Proteínas G , Receptores Histamínicos , Receptores Histamínicos H3/genética , Receptores Histamínicos H4 , Especificidade da Espécie , Tioureia/química , Tioureia/farmacologia
17.
Org Lett ; 16(14): 3760-3, 2014 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-24991702

RESUMO

The first synthesis of (-)-pericosine E (6), a metabolite of the Periconia byssoides OUPS-N133 isolated originally from the sea hare Aplysia kurodai, has been achieved. Efficient and regioselective synthetic procedures for the synthesis of key intermediates, anti- and syn-epoxides 9 and 10, were developed using an anti-epoxidation of diene 12 with TFDO and a bromohydrination of 12 with NBS in CH(3)CN/H(2)O (2:3), respectively. In addition, comparison of the specific optical rotations between synthetic 6 and natural 6 elucidated that the naturally preferred enantiomer of pericosine E had the same absolute configuration as (-)-6 synthesized from chlorohydrin (-)-8 and anti-epoxide (+)-9.


Assuntos
Aplysia/química , Ácido Chiquímico/análogos & derivados , Ácido Chiquímico/síntese química , Animais , Compostos de Epóxi/química , Biologia Marinha , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Ácido Chiquímico/química , Estereoisomerismo
18.
Bioorg Med Chem Lett ; 23(23): 6415-20, 2013 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-24140447

RESUMO

S-Alkyl-N-alkylisothiourea compounds containing various cyclic amines were synthesized in the search for novel nonimidazole histamine H3 receptor (H3R) antagonists. Among them, four N-alkyl S-[3-(piperidin-1-yl)propyl]isothioureas 18, 19, 22, and 23 were found to exhibit potent and selective H3R antagonistic activities against in vitro human H3R, but were inactive against in vitro human H4R. Furthermore, three alkyl homologs 18-20 showed inactivity for histamine release in in vivo rat brain microdialysis, suggesting differences in antagonist affinities between species. In addition, in silico docking studies of N-[4-(4-chlorophenyl)butyl]-S-[3-piperidin-1-yl)propyl]isothiourea 19 and a shorter homolog 17 with human/rat H3Rs revealed that structural differences between the antagonist-docking cavities of rat and human H3Rs were likely caused by the Ala122/Val122 mutation.


Assuntos
Antagonistas dos Receptores Histamínicos H3/farmacologia , Tioureia/síntese química , Tioureia/farmacologia , Animais , Humanos , Modelos Moleculares , Ratos , Relação Estrutura-Atividade , Tioureia/química
19.
Yakugaku Zasshi ; 133(7): 823-41, 2013.
Artigo em Japonês | MEDLINE | ID: mdl-23811770

RESUMO

Nucleoside phosphoramidites (PAs) are the most widely used building blocks in the contemporary solid-phase synthesis of oligonucleotides. Accurate molecular weight measurements of such acid-labile compounds may be easily determined in a matrix system comprising triethanolamine (TEOA)-NaCl by liquid secondary ionization mass spectrometry (LSIMS) or fast atom bombardment mass spectrometry (FABMS), using a double-focusing mass spectrometer. The present method rapidly and easily measures the accurate MWs of various PAs as adduct ions [M+Na]⁺, affording molecular formulas in place of elemental analysis. Further, the intensities by LSIMS of [M+Na]⁺ were found to be enhanced to the highest degree by adjustment of the mole ratio of PA and NaCl, fixing the amount of TEOA. In addition, the effects of the metal ion in the matrix were investigated. The present method is a powerful tool for the mass spectral identification of polyfunctionalized nucleoside PAs.


Assuntos
Amidas/análise , Nucleosídeos/análise , Ácidos Fosfóricos/análise , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Espectrometria de Massa de Íon Secundário
20.
Chem Pharm Bull (Tokyo) ; 60(12): 1550-60, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23207635

RESUMO

The divergent synthesis of natural withasomnines and analogues was achieved from 4-hydroxypyrazoles, which was prepared via alkaline hydrolysis of the Baeyer-Villiger oxidation products from 4-formylpyrazoles. Key steps of this synthesis are regioselective Claisen rearrangement of 4-allyloxypyrazoles and the Suzuki-Miyaura coupling of 5,6-dihydro-4H-pyrrolo[1,2-b]pyrazol-3-yl trifluoromethanesulfonate and commercially available arylboronic acids. The Suzuki-Miyaura coupling at the final step of this strategy enabled facile access to natural withasomnines and their analogues. The biological activities of the twelve synthesized compounds against cyclooxygenases-1 and -2 (COX-1 and COX-2) were evaluated.


Assuntos
Produtos Biológicos/farmacologia , Ciclo-Oxigenase 1/metabolismo , Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase/farmacologia , Pirazóis/farmacologia , Produtos Biológicos/síntese química , Produtos Biológicos/química , Inibidores de Ciclo-Oxigenase/síntese química , Inibidores de Ciclo-Oxigenase/química , Relação Dose-Resposta a Droga , Estrutura Molecular , Pirazóis/síntese química , Pirazóis/química , Relação Estrutura-Atividade
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