Solid-phase synthesis of a lysine-capped bis-dendron with remarkable DNA delivery abilities

Solid-phase synthesis of a generation 3.0 polyamidourea 1-->3 C-branched bis-dendron followed by capping of the peripheral amino groups with L-lysine gave an efficient transfection reagent.     

Design, synthesis, and characterization of conifer-shaped dendritic architectures

An elongated structural design leading to more conical-shaped dendritic architectures by using a combination of 1-->3, 1-->(2+1), and 1-->(2+1 Me) C-branched monomers is presented. Synthesis of the conifer-shaped macromolecule was achieved by reaction between isocyanate 20 and amine 26 in dry CH2Cl2. A resultant extended focal adamantane-modified dendron was deprotected to generate the water-soluble product, which was subsequently complexed with beta-cyclodextrin in D2O to create the desired tree-like product. Host-guest interactions of the adamantane moiety with the beta-cyclodextrin cavity were monitored by 1H NMR spectroscopy. All monomers, key intermediates, and final products were fully characterized by 1H and 13C NMR spectroscopy, ESI or MALDI-TOF mass spectrometry, and IR spectroscopy.     

Acetylene mit Elektronendonator und Elektronenakzeptorgruppen

Acetylenes having both electrondonating and electronaccepting groups ( 1 ) may be obtained in good yield from the correspondingly substituted olefines via bromination and elimination of HBr. The reaction of the acetylene aldehyde 1a with proton acids yields, after rearrangement of the primary adducts, the β-substituted acrylamides. Addition of nucleophiles leads to the β-disubstituted α.β-unsaturated carbonyl compounds. With hydrazines one obtains pyrazoles and pyrazolones. The acetylenes 1 undergo [2+2]-, [2+3]- and [2+4]-cycloaddition reactions.     

Stereoselective synthesis of natural (2E,4E)-dienamides and their synthetic analogs

A procedure has been developed for stereoselective synthesis of a number of naturally occurring (2E,4E)-dienamides and their analogs via palladium-catalyzed reaction of (1E)-1-iodoalk-1-enes with acrylamides.     

Routes to metallodendrimers: synthesis of isomeric neutral metallomacromolecules based on bis(2,2':6',2"-terpyridine)ruthenium(II) connectivity

Routes for the syntheses of isomeric, zwitterionic, bisterpyridine-Ru(II)-based macromolecules are described. Access to these novel architectures is facilitated by the construction of terpyridine-modified, 1-->3 C-branched, ester-terminated building blocks. Constitutional isomers result from the interchangable placement of methyl and tert-butyl ester groups on both the branched framework near the Ru(II) centers and the termini of the branched construct. Water solubility is imparted to each isomer through selective transformation of the tert-butyl esters to their corresponding carboxylates. Along with the standard characterization techniques, electrochemical and spectroscopic data also support the structural formation.     

Five-membered 2,3-dioxo heterocycles: CVI. Acylation of substituted (Z)-2-[1,3,4,4a,5,10b-Hexahydrophenanthridin-6(2H)-ylidene]acetamide with aroylketenes. crystal and molecular structure of substituted N-{(Z)-2-[1,3,4,4a,5,10b-Hexahydrophenanthridin-6(2H)-ylidene]acetyl}acrylamide

Aroylketenes generated by thermolysis of 6-aryl-2,2-dimethyl-4H-1,3-dioxin-4-ones reacted with (Z)-2-[4a,7,10-trimethyl-1,3,4,4a,5,10b-hexahydrophenanthridin-6(2H)-ylidene]acetamide to give (Z)-3-aryl-3-hydroxy-N-{(Z)-2-[4a,7,10-trimethyl-1,3,4,4a,5,10b-hexahydrophenanthridin-6(2H)-ylidene]acetyl}acrylamides whose structure was confirmed by X-ray analysis.     

Dendron-tethered and templated CdS quantum dots on single-walled carbon nanotubes

CdS nanoparticles on the surface of single-walled carbon nanotubes (SWNTs) were templated and stabilized through the initial attachment of 1 --> 3 C-branched amide-based dendrons and were both photophysically and morphologically characterized. The CdS clusters were shown to be ca. 1.4 nm in diameter as calculated from their optical absorption spectra and exhibited reduced fluorescence emission intensity at 434 nm compared to that of CdS quantum dots stabilized by untethered dendrons due to partial emission quenching by the SWNT. Unchanged UV absorption behavior of these materials indicated that they are stable > 90 days at 25 degrees C.     

Five new phenylethanoid glycosides from the whole plants of Lamium purpureum L

Five new phenylethanoid glycosides, lamiusides A (1), B (2), C (3), D (4) and E (5), were isolated from the whole plants of Lamium purpureum L. (Labiatae) together with seven known compounds (6-12). On the basis of chemical and spectral analyses, the structures of the new compounds were elucidated to be 2-(3,4-dihydroxyphenyl)ethyl-O-beta-D-galactopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->3)-(4-O-trans-caffeoyl)-beta-D-glucopyranoside (1), 2-(3,4-dihydroxyphenyl)ethyl-O-beta-D-galactopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->3)-(4-O-trans-feruloyl)-beta-D-glucopyranoside (2), 2-(3,4-dihydroxyphenyl)ethyl-O-beta-D-galactopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->3)-(6-O-trans-caffeoyl)-beta-D-glucopyranoside (3), 2-(3,4-dihydroxyphenyl)-R,S-methoxy-ethyl-O-beta-D-galactopyranosyl-(1-->2)-alpha-L-rhamnopyranosyl-(1-->3)-(4-O-trans-caffeoyl)-beta-D-glucopyranoside (4) and 2-(3-hydroxy-4-methoxyphenyl)ethyl-O-alpha-L-rhamnopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->6)-(4-O-cis-feruloyl)-beta-D-glucopyranoside (5). In addition, the radical-scavenging activities of compounds 1-4 on 1,1-diphenyl-2-picrylhydrazyl radical were examined.     

Bioactive saponins and glycosides. XVI. Nortriterpene oligoglycosides with gastroprotective activity from the fresh leaves of Euptelea polyandra Sieb. et Zucc. (1): structures of Eupteleasaponins I, II, III, IV, V, and V acetate

The saponin fraction from the fresh leaves of Euiptelea polyandra Sieb. et Zucc. was found to exhibit potent gastroprotective activity. Fourteen new nortriterpene saponins called eupteleasaponins were isolated from the saponin fraction with gastroprotective activity. The structures of eupteleasaponins I, I1, III, IV, V, and V acetate were determined on the basis of chemical and physicochemical evidence as 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl(1 -->3)-beta-D-xylopyranosylakebonoic acid 28-O-beta-D-glucopyranosyl ester, 3-O-alpha-L-rhamnopyranosyl(1-->2)-[alpha-L-rhamnopyranosyl(1 -->4)-beta-D-glucopyranosyl(1-->3)-beta-D-xylopyranosylakebonoic acid 28-O-beta-D- D-glucopyranosyl(1-->3)-beta-D-xylopyranosylakebonoic acid 28-O-beta-D-glucopyranosyl ester, 3-O-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-rhamnopyranosyl(1 -->4)-beta-D-glucopyranosyl(1-->3)-beta-D-xylopyranosylakebonoic acid 28-O-beta-D-glucopyranosyl ester, 3-O-alpha-L-rhamnopyranosyl(1 -->2)-[alpha-L-arabinopyranosyl(1-->4)-alpha-L-rhamnopyranosyl(1-- >4)]-beta-D- glucopyranosyl(1-->3)-beta-D-xylopyranosylakebonoic acid 28-O-beta-D-glucopyranosyl ester, 3-O-alpha-L-rhamnopyranosvl(1-->2)-[alpha-L-arabinopyranosyl (1 -->4)-beta-L-rhamnopyranosyl(1 -->4)]-beta-D-glucopyranosyl(1 -->3)-beta-D-xylopyranosylakebonoic acid, 3-O-alpha-L-rhamnopyranosyl(1 -->2)-beta-D-glucopyranosvl(1-->3)-beta-D-xylopyranosyleupteleo genin, and 3-O-alpha-L-rhamnopyranosyl(1-->2)-6"-O-acetyl-gamma-D-glucopyranosyl(1 -->3)-beta-D-xylopyranosyleupteleogenin.     

New saponins from the seeds of Aesculus chinensis

Eight new acylated polyhydroxyoleanene triterpenoidal saponins, aesculiosides A-H (1-8), along with four known ones, have been isolated from the seeds of Aesculus chinensis. On the basis of extensive NMR studies, the structures of the new compounds were determined to be 21-O-tigloylprotoaescigenin 3-O-[beta-D-glucopyranosyl-(1-->2)][beta-D-glucopyranosyl-(1-->4)]- beta-D-glucuronopyranosyl acid (1), 21-O-angeloylprotoaescigenin 3-O-[beta-D-glucopyranosyl- (1-->2)][beta-D-glucopyranosyl-(1-->4)]-beta-D-glucuronopyranosyl acid (2), 21,22-O-ditigloylprotoaescigenin 3-O-[beta-D-glucopyranosyl-(1-->2)][beta-d-glucopyranosyl- (1-->4)]-beta-D-glucuronopyranosyl acid (3), 21-O-tigloyl-22-O-angeloylprotoaescigenin 3-O-[beta-D-glucopyranosyl- (1-->2)][beta-D-glucopyranosyl-(1-->4)]-beta-D-glucuronopyranosyl acid (4), 21,22-O-ditigloylprotoaescigenin 3-O-[beta-D-glucopyranosyl- (1-->2)][beta-D-glucopyranosyl-(1-->4)]-methyl beta-d-glucuronopyranosate (5), 21-O-tigloyl-22-O-angeloylprotoaescigenin 3-O-[beta-D-glucopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->4)]-methy l beta-D-glucuronopyranosate (6), 21-O-tigloyl-28-O-acetylprotoaescigenin 3-O-[beta-D-glucopyranosyl-(1-->2)][beta-D-glucopyranosyl-(1-->4)]-methy l beta-D-glucuronopyranosate (7) and 21-O-angeloyl-28-O-acetylprotoaescigenin 3-O-[beta-D-glucopyranosyl-(1-->2)][beta-D-glucopyranosyl-(1-->4)]-methy l beta-D-glucuronopyranosate (8).     

Efficient,Simple Preparation of 1,3‐Diamine Derivatives through Addition of Acrylamides with Secondary Amines

Abstract

Reaction of acrylamides with secondary amines results in the formation of β‐amino‐propionamide through the addition reaction of N–H bond of amines across the double bond of acrylamides in the good to excellent yield. The structure of 2‐methyl‐3‐(1‐piperidinyl)‐propionamide has been determined by X‐ray analysis.     

Ardisimamillosides C-F, four new triterpenoid saponins from Ardisia mamillata

Four new triterpenoid saponins, ardisimamilloside C (1), 3-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->4)-[beta -D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl]-3beta,16al pha,28,30-tetrahydroxy-olean-12-en, ardisimamilloside D (2), 3-O-?alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->4)-[beta -D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl]-3beta,15al pha,28,30-tetrahydroxy-olean-12-en, ardisimamilloside E (3), 3-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->4)-[beta -D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosl]-13beta,2 8-epoxy-3beta,16alpha,29-oleananetriol, and ardisimamilloside F (4), 3-O-[alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->4)-[beta -D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl]-3beta,16al pha-dihydroxy-13beta,28-epoxy-oleanan-30-oic acid were isolated from the roots of Ardisia mamillata Hance. Structure assignments were established on the basis of highresolution (HR)-FAB-MS, 1H-, 13C-, and two-dimensional (2D)-NMR spectra, and on the chemical evidence.     

New phenylethanoid glycosides from Veronica pectinata var. glandulosa and their free radical scavenging activities

A known phenylethanoid glycoside, ehrenoside (1), was isolated together with three new phenylethanoid glycosides, verpectoside A (2), B (3) and C (4) from the aerial parts of Veronica pectinata var. glandulosa. On the basis of spectral analysis (UV, FAB-MS, 1H-, 13C- and 2D-NMR), compounds 2-4 were determined to be 2-(3,4-dihydroxyphenyl)ethyl-O-alpha-L-arabinopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->3)]-(4-O-trans-feruloyl)-beta-D-glucopyranoside, 2-(3,4-dihydroxyphenyl)ethyl-O-beta-D-glucopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->3)]-(4-O-trans-caffeoyl)-beta-D-glucopyranoside and 2-(3,4-dihydroxyphenyl)ethyl-O-beta-D-glucopyranosyl-(1-->2)-[alpha-L-rhamnopyranosyl-(1-->3)]-(4-O-trans-feruloyl)-beta-D-glucopyranoside, respectively. Isolated phenylethanoid glycosides exhibited potent radical scavenging activity against the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical.     

Steroidal oligoglycosides from Solanum nigrum

Two new steroidal saponins, named nigrumnins I and II, together with two known saponins were obtained from the whole plant of Solanum nigrum L. On the basis of spectroscopic analysis (1H-NMR, 13C-NMR, 1H-1H COSY, TOCSY, HMQC, HMBC and FAB-MS), nigrumnin I was established as (25R)-5alpha-spirostan-3beta-ol 3-O-betaD-xylopyranosyl-(1-->3)-[alpha-L-arabinopyranosyl-(1 -->2)]-beta-D- glucopyranosyl-(1-->4)-[alpha-L-rhamnopyranosyl(1-->2)]-beta-D- galactopyranoside (1), and nigrumnin II was elucidated as (25R)-3beta,17alpha-dihydroxy-5alpha-spirostan-1 2-one 3-O-beta-D-xylopyranosyl-(1-->3)-[alpha-L-arabinopyranosyl-(1--> 2)]-beta-D-glucopyranosyl-(1-->4)-[alpha-L-rhamnopyra- nosyl-(1-->2)l-beta-D-galactopyranoside (2).     

Ni-Catalyzed desilylative annulation of benzamides and acrylamides with alkynylsilanes: Access to 3-Methyleneisoindolin-1-one and 5-Methylene-1H-pyrrol-2(5H)-one derivatives

Abstract

The nickel-catalyzed desilylative annulation of C(sp²)–H bonds of benzamides and acrylamides with alkynylsilanes assisted by 8-aminoquinolyl directing group has been reported. A variety of benzamides and acrylamides were compatible in this protocol to construct various 3-methyleneisoindolin-1-one and 5-methylene-1H-pyrrol-2(5H)-one derivatives with Z-configuration selectivity in moderate to high yields.     

Green Polymer Chemistry: Microwave‐Assisted Single‐Step Synthesis of Various (Meth)acrylamides and Poly(meth)acrylamides Directly from (Meth)acrylic Acid and Amines

Summary: Various (meth)acrylamides were synthesized in good yields directly from (meth)acrylic acid and an amine using microwave irradiation in a solvent‐free environment. Under the applied conditions the (meth)acrylic function is preserved. Furthermore, the addition of an initiator like 2,2′‐azoisobutyronitrile (AIBN) to the starting mixture leads directly to poly(meth)acrylamides in a single step.

General reaction scheme for the formation of poly(meth)acrylamides from the microwave‐assisted reaction of (meth)acrylic acid and various amines.     

Five new bidesmoside triterpenoid saponins from Stauntonia chinensis

Eleven triterpenoid saponins (1-11) were isolated from Stauntonia chinensis DC. (Lardizabalaceae), including five new compounds, yemuoside YM(21-25) (1-3, 6, 7) structures of which were elucidated by chemical methods and a combination of MS, 1D- and 2D- NMR experiments including DEPT, (1)H--(1)H COSY, HSQC, HMBC, TOCSY, and NOESY as 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-[alpha-L-rhamnopyranosyl-(1 --> 2)-]alpha-L-arabinopyranosyl-akebonicacid-28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (1), 3-O-beta-D-xylopyranosyl-(1 --> 3)-alpha-L-rhamnopyranosyl-(1 --> 2)-alpha-L-arabinopyranosyl-akebonic acid-28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (2), 3-O-beta-D-glucopyranosyl-(1 --> 3)-alpha-L-arabinopyranosyl-akebonic acid-28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (3), 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-[alpha-L-rhamnopyranosyl-(1 --> 2)-]alpha-L-arabinopyranosyl-akebonic acid-28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (6), 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-[alpha-L-arabinopyranosyl-(1 --> 2)-]alpha-L-arabinopyranosyl-akebonic acid-28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (7).     

Synthesis of fragments of the glycocalyx glycan of the parasite Schistosoma mansoni

The chemical synthesis of alpha-L-Fucp-(1 --> 3)-beta-D-GalpNAc-(1 --> 4)-beta-D-GlcpNAc-(1 --> 3)-alpha-D-GalpO(CH2)5NH2, beta-D-GalpNAc-(1 --> 4)-[alpha-L-Fucp-(1 --> 3)-]beta-D-GlcpNAc-(1 --> 3)-alpha-D-GalpO(CH2)5NH2, and alpha-L-Fucp-(1 --> 3)-beta-D-GalpNAc-(1 --> 4)-[alpha-L-Fucp-(1 --> 3)-]beta-D-GlcpNAc-(1 --> 3)-alpha-D-GalpO(CH2)5NH2 is described. These structures represent fucosylated oligosaccharide fragments of the glycocalyx glycan of the cercarial stage of the parasite Schistosoma mansoni, and in protein-conjugated form they are potential diagnostics in the search for antibodies raised against the glycan in the serum of infected humans.     

Two new triterpenoid saponins isolated from Polygala japonica

Bioassay guided investigation of whole parts of Polygala japonica afforded two new triterpenoid saponins, characterized as 3-O-beta-D-glucopyranosyl medicagenic acid 28-O-{beta-D-xylopyranosyl(1-->4)-[beta-D-apiofuranosyl(1-->3)]-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl} ester (1), 3-O-beta-D-glucopyranosyl 2-oxo-olean-12-en-23, 28-dioic acid 28-O-{beta-D-xylopyranosyl(1-->4)-[beta-D-apiofuranosyl(1-->3)]-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl} ester (2), together with four known triterpenoid saponins (3-6). Their structures were elucidated by spectroscopic and chemical methods. Saponins 3, 4 and 5 showed significant anti-inflammation effects on carrageenan-induced acute paw edema in mouse.     

Pancreatic lipase-inhibiting triterpenoid saponins from Gypsophila oldhamiana

Three new triterpenoid saponins, gypsosaponins A-C (1-3), were isolated from the roots of Gypsophila oldhamiana (Caryophyllaceae). Their structures were established as 3-O-beta-D-galactopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-beta-D-glucuronopyranosyl quillaic acid 28-O-alpha-L-arabinopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-fucopyranoside (1), 3-O-beta-D-galactopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)]-methyl-beta-D-glucuronopyranosyl gypsogenin 28-O-beta-D-glucopyranosyl-(1-->3)-[beta-D-xylopyranosyl-(1-->4)]-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-fucopyranoside (2), and 23-O-beta-D-glucopyranosyl gypsogenic acid 28-O-beta-D-glucopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->6)]-beta-D-glucopyranoside (3), on the basis of various spectroscopic analyses and chemical degradations. The biological activities of 1-3 were examined inhibitory activity against pancreatic lipase, which showed inhibition of 58.2%, 99.2% and 50.3% at concentration of 1 mg/ml, respectively.