检索结果-南通市图书馆

Chiral Synthesis of the Key Intermediate of Diterpenoids

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1997年第11期8卷 949-950页

作者： Hao, XJ Node, MB Fuji, KR Chinese Acad Sci Kunming Inst Bot Kunming 650204 Peoples R China Kyoto Pharmaceut Univ Yamashima Ku Kyoto 607 Japan Kyoto Univ Inst Chem Res Uji 611 Japan

(-)-Methyl(4R, 5S, 10R)-14-methoxypodocarpa-8, 11, 13-triene-19-oate(1), which is the key intermediate for synthesis of diterpenoids, was synthesized from (R)-(+)-2-methyl-2-(2`-nitrovinyl)-delta-valerolactone(2).

关键词： ADDITION ELIMINATION PROCESS NITROOLEFINATION lactones

维普期刊数据库

Synthesis of （-）-Harzialactone A from a Readily Accessible Epoxy Chiral Building Block

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2011年第12期29卷 2664-2668页

作者：何蕾张少敏伍贻康李焰 Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules and School of Chemistry and Chemical Engineering Hubei University Wuhan Hubei 430062 China State Key Laboratory of Bioorganic and Natural Products Chemistry Shanghai Institute of Organic Chemistry Chinese Academy of Sciences Shanghai 200032 China

The antipode of （＋）-harzialactone A, an antitumor marine metabolite, was synthesized with the two stereogenic centers in the target structure taken from an optically active epoxy cbiral building block.

关键词： natural products chiral building blocks epoxides lactones condensation

Synthesis and characterization of biodegradable aliphatic polyesters using dibutylmagnesium as initiator

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2007年第6期18卷 744-746页

作者： Lian Liu Zhi Yong Wei Min Qi Electromechanics and Materials Engineering College Dalian Maritime University Dalian 116026 China School of Materials Science and Engineering Dalian University of Technology Dalian 116024 China

Aliphatic polyesters were synthesized via the ring opening polymerization of the corresponding lactones initiated with dibutylmagnesium both in bulk and in solution. The resulting polymers were characterized by 1 H, 13 C NMR, GPC and XRD. The results indicated that dibutylmagnesium is an effective initiator for the ring opening polymerization of lactones.

关键词： Aliphatic polyesters lactones Dibutylmagnesium Biodegradable Biomaterials

维普期刊数据库

Fractions of a chloroform extract of ajenjo leaves (Artemisiamendozana DC. var. mendozana) inhibit the proliferation,viability and clonogenicity of B16-F0 melanoma cells

在线全文

学校读者我要写书评

暂无评论

BIOCELL 2020年第3期44卷 293-299页

作者： MARÍA ELISA MILLÁN MARÍA FERNANDA MARRA LEONARDO ANDRÉS SALVARREDI EMILIO FERNANDO LIZARRAGA LUIS ALBERTO LOPEZ Universidad Nacional de Cuyo MendozaArgentina Comisión Nacional de Energía Atómica Buenos AiresArgentina Fundación Escuela de Medicina Nuclear MendozaArgentina Fundación Miguel Lillo y Universidad Nacional de Tucumán San Miguel de TucumánArgentina

The ajenjo,Artemisia mendozana ***(Asteraceae),grows in the Andean foothills of Mendoza and San Juan,Argentina,and is used as a medicinal plant for its antispasmodic and antifungal *** aim of this work was to obtain fractions of a chloroform extract of ajenjo leaves and to evaluate the in vitro effects on proliferation,viability and clonogenicity of B16-F0 melanoma *** a silica gel chromatography column,120 fractions were collected and grouped according to the chromatographic profile in 9 main fractions(F1–F9).Their major compounds identified were:terpenes(F1),terpenes and sesquiterpene lactones(F2–F3),sesquiterpenes(F4–F6)and phenols and sesquiterpenes(F7-9).B16-F0 cells were incubated for 72 h with DMSO(vehicle)or 0.1 mg/ml F1–*** 72 h of culture,F1 decreased both the growing index(GI)and cell viability.F2 and F3 both decreased GI and only F3 decreased clonogenic activity.F4 and F5 both decreased *** F5 decreased cell viability and F4 decreased ***,fractions F6–F8 did not affect any of the cell parameters assayed,while F9 decreased cell viability and inhibited clonogenicity.

关键词： Terpenes Sesquiterpene lactones Sesquiterpenes Phenols

Carboxymethyl glycoside lactone(CMGL) synthons:Scope of the method and preliminary results on step growth polymerization of α-azide-ω-alkyne glycomonomers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2010年第9期53卷 1880-1887页

作者： CHAMBERT Stéphane BERNARD Julien FLEURY Etienne QUENEAU Yves INSA-Lyon Laboratoire de Chimie Organique et Bioorganique Bat.J.Verne 20 Avenue A.Einstein69621 Villeurbanne CedexFrance ICBMS Institut de Chimie et de Biochimie Moléculaires et SupramoléculairesUMR5246 CNRS université de Lyon université Lyon 1 INSA-Lyon CPE-Lyon Bat.Curien 43 Bd du 11 Novembre 1918F 69622 VilleurbanneFrance INSA-LYON IMP1ngénierie des Matériaux Polymères UMR5223 université de Lyon université Claude Bernard Lyon 1F-69621 Villeurbanne CedexFrance

Carboxymethyl glycoside lactones(CMGLs) are bicyclic synthons which open readily for accessing new types of pseudo-glycoconjugates,such as sugar-amino acid hybrids,neoglycolipids,pseudodisaccharides,and membrane imaging *** lactone opening,free OH-2 is available for further functionalization,leading to 1,2-bisfunctionalized *** strategy is illustrated herein with new polymerizable systems of the AB type bearing both azide and alkyne functions prepared from α or β gluco-CMGL *** the reaction of lactones with propargylamine,an azido group was introduced by two different sequences leading to either the 2-manno-azido or the 6-gluco-azido *** capability of these AB monomers to undergo step growth polymerization through copper(I) catalyzed alkyne-azide cycloaddition(CuAAC) and generate glycopolytriazoles was evidenced.

关键词： carbohydrates glycopolymers lactones click chemistry step growth polymerization glycoconjugates azides alkynes Huisgen cycloaddition

维普期刊数据库

Progress toward the Synthesis of Pochonin J

在线全文

学校读者我要写书评

暂无评论

International Journal of Organic Chemistry 2019年第2期9卷 96-105页

作者： Sydney N. Jackson Rongson Pongdee Department of Chemistry The University of the South Sewanee USA

The construction of the C(1) - C(5) fragment of the resorcylic acid lactone pochonin J is described. The synthesis is marked by the installation of the cis-1,3-diol moiety in a highly stereoselective manner using Evans’ intra-molecular base-catalyzed oxyconjugate addition of a hemiacetal-derived nucleophile. The synthetic route presented affords an efficient pathway to the preparation of this critical architectural feature that should facilitate the development of this secondary metabolite as a potential drug candidate.

关键词： Natural Products Pochonin J Resorcylic Acid lactones

Synthesis and Characterization of New Chiral Monoanionic [ON] Ancillary Phenolate Ligands

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Organic Chemistry 2014年第3期4卷 182-188页

作者： Pascal Binda Leslie Glover Department of Chemistry and Forensic Science Savannah State University Savannah GA USA Science Division Southern Wesleyan University Central SC USA

Three new chiral monoanionic [ON] ancillary phenolate ligands with varying pendant arms have been synthesized in moderate to high yields (50% - 85%) via Mannich-type condensation reaction of chiral substituted phenol, formaldehyde and (+)-bis-[(R)-1-phenylethyl]amine. These new organic compounds were fully characterized via nuclear magnetic resonance spectroscopy (1H and 13C) and elemental analysis. The newly synthesized ligands are suitable candidates for metal-catalyzed ring-opening of lactones and asymmetric catalysis.

关键词： Phenolate Ligands Mannich Condensation Reaction Ring-Opening Polymerization of lactones

Enzymatic Synthesis and Characterization of Biodegradable Poly(w-pentadecalactone-co-ε-caprolactone)Copolymers

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Renewable Materials 2018年第6期6卷 591-598页

作者： Cansu Ulker Yuksel Guvenilir Istanbul Technical University Department of Chemical Engineering34469IstanbulTurkey

As an alternative biodegradable aliphatic polyester,poly(w-pentadecalactone-co-ε-caprolactone)copolymer was synthesized via enzymatic ring-opening polymerization.A new biocatalyst,Candida antarctica lipase B,immobilized onto rice husk ash was used for *** were carried out at various temperatures and periods for varied copolymer compositions in order to obtain the highest molecular weight *** best reaction parameters were found to be 80℃ and 6 hours and molecular weights increased proportionally with the amount of w-pentadecalactone(w-PDL).The molecular structure of copolymer with 75%weight ratio of w-PDL(Mn=19720 g/mol)was characterized by proton and carbon nuclear magnetic resonance spectroscopies(^1H-NMR and ^13C-NMR).Thermal properties of the same copolymer and homopolymers were investigated by differential scanning calorimetry(DSC)and thermogravimetric analysis(TGA).Improved thermal features were shown by addition of w-PDL to the structure and compared with poly(ε-caprolactone)(PCL).Consequently,poly(w-pentadecalactone-co-ε-caprolactone)copolymers were found to be good alternatives to widely used polyester,PCL,with their rapid polymerization tendency,higher molecular weights,and improved thermal features.

关键词： Candida antarctica lipase B immobilized lipase rice husk ash copolymerization enzymatic ring-opening polymerization lactones ε-caprolactone ω-pentadecalactone