A New Brominated Phenylpropylaldehyde and its Dimethyl Acetal from Red Alga Rhodomela confervoides

A new brominated phenylpropylaldehyde and its dimethyl acetal together with a new natural brominated phenol were isolated from Rhodomela confervoides. Their structrues were elucidated as 2-methyl-3-(2,3-dibromo-4,5-dihydroxyphenyl)propylaldehyde, 2-methyl-3-(2,3-di-bromo-4,5-dihydroxyphenyl) propylaldehyde dimethyl acetal and 3-bromo-4,5-dihydroxybenzoic acid methyl ester by spectroscopic techniques including IR, HRFABMS, 1D and 2DNMR experiments.     

Oxyphyllones A and B,novel sesquiterpenes with an unusual 4,5-secoeudesmane skeleton from Alpinia oxyphylla

Two novel 4,5-secoeudesmane sesquiterpenoids,oxyphyllones A(1) and B(2) were isolated from the fruits of Alpinia oxyphylla.Their structures were established by spectroscopic methods including 1D and 2D NMR spectra.These two compounds are the first example of naturally occurring sesquiterpenoids with a 4,5-secoeudesmane skeleton in the family of Zingiberaceae and oxyphyllone A(1) is the first 4,5-secoeudesmane type of 13-norsesquiterpenoid.Compounds 1 and 2 exhibited no cytotoxicities against three cancer...     

A Novel 3D Cd(II) Coordination Polymer with an Unusual 3-Connected(8~2·10) Lig Net: Synthesis,Crystal Structure and Luminescent Properties

A new 3D Cd(II) coordination polymer, [Cd(Hpidc)]n(1, H3 pidc = 2-(pyrid-2-yl)-1H-imidazole-4,5-dicarboxy acid), has been prepared and characterized by elemental analysis, IR spectra, PXRD, and single-crystal X-ray diffraction. Compound 1 crystallizes in orthorhombic, space group Fdd2 with a = 22.833(9), b = 25.536(9), c = 7.437(3) A, V = 4336(3) A3, Z = 16, Dc = 2.105 Mg·m-3, μ = 2.025 mm-1, F(000) = 2656, and the final R = 0.0261 and w R = 0.0636. The structure determination reveals that 1 exhibits a rare 3D 3-connected lig net with a point symbol of(82·10). In addition, the solid state properties such as thermogravimetric analysis and luminescence of 1 were also studied.     

Two new phenylpropanoid glycosides from Sanguisorba officinalis

Two new phenylpropanoid glycosides,9-O-[6-O-acetyl-β-D-glucopyranosyl]-4-hydroxycinnamic acid(1) and 8-O-β-D-glucopyranosyl -(R)-(+)-3,4,8-trihydroxy methyl phenylpropionate(2) were isolated from the 80%EtOH extract of the roots of Sanguisorba officinalis.Their structures were characterized by spectroscopic analysis and chemical method,including 1D NMR,2D NMR,and HR-ESI-MS.Compounds 1 and 2 exhibited the moderate antimicrobial activities against all Gram-positive and Gram-negative bacteria tested.     

Syntheses,Electrochemical Behaviors,Spectral Properties and DFT Calculations of Two 1,3-Dithiole Derivatives

Two new 1,3-dithiole derivatives, 4,4＇-{9-[4,5-bis（methylthio）-1,3-dithiol-2-ylidene]-9H-fluorene-2,7- diyl} dipyridine（2a） and 3,3＇-{9-[4,5-bis（methylthio）-1,3-dithiol-2-ylidene]-9H-fluorene-2,7-diyl} dipyridine（2b） were synthesized and characterized by Fourier transform infrared（FTIR）, 1H NMR, 13C NMR and mass spectroscopies. The crystal structure of compound 2b was also studied. The optimized conformations and molecular orbital diagrams of compounds 2a and 2b were illustrated via density functional theory（DFT）. By the time-dependent DFT（TD-DFT） method, electronic absorption spectra of compounds 2a and 2b were predicted and the results achieved were in good agreement with the experimental data. The formation of the cationic radical during the electrochemical oxidation process was also proposed.     

Synthesis and photochromism of dimers of 4,5- diaryl-2-(2,5-dimethylthiophen-3-yl)imidazolyl

4,5-Diphenyl, 4,5-di(4-methylphenyl), 4,5-di(4-methoxyphenyl)-2-(2,5-dimethylthioph-en-3-yl)imidazoles were synthesized. Oxidation of the obtained imidazoles with potassium ferricyanide in water-alcohol solution of alkali gave the corresponding dimers. The structures were characterized by IR, 1H NMR, mass spectroscopy and elemental analysis. The dimers showed photochromism in solution on irradiation.     

Xanthones from the bark of Garcinia Xanthochymus

Two novel xanthones, 1,6-dihydroxy-4,5-dimethoxyxanthone (1) and 1,5,6-trihydroxy-7,8-di(3-methyl-2-butenyl)-60,60- dimethylpyrano(20,30:3,4)xanthone (2) were isolated from the bark of Garcinia xanthochymus by normal phase and reverse phase silica gel column chromatography. Their structures were elucidated by spectroscopic methods, especially 2D-NMR techniques.     

Two New Sesquiterpenes from Euonymus nanoides

Two new dihydroagarofuran sesquiterpenes with a novel substitution pattern:1α-(α-methyl)-butanoyl-2α,15-diacetoxy-4β-hydroxy-9β-(β-)furancarboxy-β-dihydroagarofuran (1) and 1α,2α-di-(α-methyl)-butanoyl-4β-hydroxy-9β-(β-)furancarboxy-15-acetoxy-β-dihydro-agaro-furan (2) were isolated from Euonymus nanoides. Their structures were elucidated by means of ^1H and ^13C NMR spectroscopic studies, including 2D NMR technique.     

Three new diarylheptanoids and their antioxidant property

Three new diarylheptanoids,i.e.,sodium(5S,2E)-1,7-bis(4-hydroxyphenyl)-1-hydroxy-2-hepten-5-sulfonate(1), sodium(5R,2E)-1,7-bis(4-hydroxyphenyl)-1-hydroxy-2-hepten-5-sulfonate (2) and 3,5-diacetoxy-1-(3-methoxy-4,5-dihydroxy- phenyl)-7-(4-hydroxy-3-methoxyphenyl)heptane (3) were isolated from the rhizomes of Zingiber officinale.The structures of the new compounds were elucidated on the basis of spectroscopic methods.The antioxidant activities of 3 were assayed by in vitro models involving DPPH free radicals and superoxide anion radicals.     

A Novel Stereoselective Synthesis of 8-O-4' Neolignans

1-(4-hydroxy-3-methoxyphenyl)-2-(4-formyl-2-methoxyphenoxy)-propane-1,3-diol 9, a natural 8-O-4' neolignan, was isolated as a mixture of erythro and threo isomers from wood of Larix leptolesis1. This kind of neolignans have shown various biological activities2-4.As reported previously, the synthesis of 8-O-4' neolignans was mainly achieved using oxidative coupling of monolignols4,5 and reduction of ketones which were prepared from bromoketone and phenols in basic conditions6, But these method…     

Three New Neolignans and One New Phenylpropanoid from the Leaves and Stems of Toona ciliata var. pubescens

Three new neolignans, (7S,8S,7′E)‐4,9‐dihydroxy‐3,7,3′,9′‐tetramethoxy‐8,4′‐oxyneolign‐7′‐ene ( 1 ), (7R,8S,7′E)‐4, 9‐dihydroxy‐3,7,3′,9′‐tetramethoxy‐8,4′‐oxyneolign‐7′‐ene ( 2 ), (7S,8S,7′E)‐5, 9‐dihydroxy‐3,7,3′,5′,9′‐pentamethoxy‐8,4′‐oxyneolign‐7′‐ene ( 3 ), and one new phenylpropanoid, threo‐5‐hydroxy‐3,7‐dimethoxyphenylpropane‐8,9‐diol ( 4 ), were isolated from the leaves and stems of Toona ciliata var. pubescens. Their structures were determined on the basis of spectroscopic analysis, especially 2D‐NMR, HR‐ESI‐MS, and CD data. The antiproliferative activities of these compounds against four tumor cell lines (A549, Colo 205, QGY‐7703, and LOVO) were also evaluated by MTT (=(3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyl‐2H‐tetrazolium bromide) method.     

Stereochemical assignment of five new lignan glycosides from Viscum album by NMR study combined with CD spectroscopy

The chemical study of the leaves and twigs of Viscum album led to the isolation of five new lignan glycosides, namely, ligalbumosides A–E (2‐6) and one known lignan glycoside, alangilignoside C (1). The structures of five new lignan glycosides were determined to be (7R,8S,8'S)‐4,9,4'‐trihydroxy‐3,5,3',5'‐tetramethoxy‐7,9'‐epoxylignan 9‐O‐β‐D‐glucopyranoside (2), (7S,8S,7'S,8'R)‐4,9,4'‐trihydroxy‐3,5,3',5',7'‐pentamethoxy‐7,9'‐epoxylignan 9‐O‐β‐D‐glucopyranoside (3), (7R,8R,7'S,8'S)‐4,9,4'‐trihydroxy‐3,5,3',5',7'‐pentamethoxy‐7,9'‐epoxylignan 9‐O‐β‐D‐glucopyranoside (4), (7S,8R,7'S,8'R)‐4,9,4'‐trihydroxy‐3,5,3',5',7'‐pentamethoxy‐7,9'‐epoxylignan 9‐O‐β‐D‐glucopyranoside (5), and (7R,8S,7'R,8'S)‐4,9,4',7'‐tetrahydroxy‐3,5,3',5'‐tetramethoxy‐7,9'‐epoxylignan 9‐O‐β‐D‐glucopyranoside (6) using 1D‐, 2D‐NMR, and CD spectra, chemical methods, as well as comparing the results with those reported in the literature. Copyright © 2012 John Wiley & Sons, Ltd.     

Water and the Huisgen Cycloaddition Reaction: A Focus on Polar Contributions to the Transition State in the Reactions of Dicyano(phthalazinium)methanide with Substituted Styrenes and Benzylidene Acetones

Synthetic and kinetic studies on the 1,3‐dipolar cycloaddition reactions of dicyano(phthalazin‐2‐ium‐2‐yl)methanide ( 1 ) with some substituted styrenes and ‘benzylidene acetones’ in MeCN and H₂O containing 10 mol‐% of MeCN are reported. The kinetic data were supported by theoretical calculations. The major products from styrenes were exo‐2‐aryl‐1,2,3,10b‐tetrahydropyrrolo[2,1‐a]phthalazine‐3,3‐dicarbonitriles 3 , and, from ‘benzylidene acetones’, 1‐endo,2‐exo‐2‐acetyl‐1‐aryl‐1,2,3,10b‐tetrahydropyrrolo[2,1‐a]phthalazine‐3,3‐dicarbonitriles 7 . There was no indication that the cycloadditon transition states were more polar in the aqueous environment than in MeCN.     

Identification of Three New Flavonoids from the Peels of Citrus unshiu

Three new flavonoids, 5,6,7,8,3′,4′‐hexamethoxyhomoflavone ( 1 ), 5,6,7,8,4′‐pentamethoxyhomoflavone ( 2 ) and 3,6,7,8,2′,5′‐hexamethoxyflavone ( 3 ) were isolated from the peels of mature fruits of Citrus unshiu Marcow (Rutaceae), together with the three known compounds 6,7,8,4′‐tetramethoxyflavone (=6,7,8‐trimethoxy‐2‐(4‐methoxyphenyl)‐4H‐1‐benzopyran‐4‐one), 3,5,7,8,2′,5′‐hexamethoxyflavone (=2‐(2,5‐dimethoxyphenyl)‐3,5,7,8‐tetramethoxy‐4H‐1‐benzopyran‐4‐one), and scopoletin (=7‐hydroxy‐6‐methoxy‐2H‐1‐benzopyran‐2‐one) of which the former two have never been isolated from natural resources, although they have been reported as synthetic compounds. The structures of 1 – 3 were elucidated on the basis of spectroscopic evidence, including 1D‐ and 2D‐NMR analysis.     

Synthesis of pyrrolo[2,1‐a]phthalazines by 1,3‐dipolar cycloaddition of phthalazinium N‐ylides with alkenes in the presence of tetrakis‐pyridine cobalt (II) dichromate

We describe here, for the first time, that 1‐cyano‐3‐benzoyl‐1,2,3,10b‐tetrahydropyrrolo[2,1‐a]phthalazine (8), prepared by 1,3‐dipolar cycloaddition of 2‐phenacyl phthalazinium bromide ( 6a ) with acrylonitrile ( 7a ), can be aromatized by tetrakis‐pyridine cobalt (II) dichromate (TPCD) to give 1‐cyano‐3‐benzoylpyrrolo[2,1‐α]phthalazine ( 9a ) in good yield. Furthermore, a general and convenient one‐pot procedure for preparation of pyrrolo[2,1‐α]phthalazines ( 9a‐p ) was developed by 1,3‐dipolar cycloaddition of phthala zinium N‐ylides ( 6a‐c ) with alkenes ( 7a‐g ) in the presence of TPCD.     

Rubriflorin A and B,Two Novel Partially Saturated Dibenzocyclooctene Lignans from Schisandra rubriflora

From the stems of Schisandra rubriflora, two novel partially saturated dibenzocyclooctene lignans, named rubriflorin A ( 1 ) and B ( 6 ), as well as the seven known partially saturated dibenzocyclooctene lignans kadsumarin A ( 2 ), kadsurin ( 3 ), heteroclitin B ( 4 ), heteroclitin C ( 5 ), heteroclitin D ( 7 ), interiorin ( 8 ), and interiorin B ( 9 ) were isolated. The structures of the new compounds 1 and 6 were established on the basis of spectral analysis as (5R,6S,7R,8R,13aS)‐8‐(acetyloxy)‐5,6,7,8‐tetrahydro‐1,2,3,13‐tetramethoxy‐6,7‐dimethylbenz([3,4]cycloocta[1,2‐f][1,3]benzodioxol‐5‐yl (2Z)‐2‐methylbut‐2‐enoate and (6R,7R,12aS)‐7,8‐dihydro‐12‐hydroxy‐1,2,3,10,11‐pentamethoxy‐6,7‐dimethyl‐6H‐dibenzo[a,c]cycloocten‐5‐one, respectively.     

Terpenoids from the Flower of Cacalia Tangutica

A thorough investigation of Cacalia tangutica (Franch.) Hand‐Mazz afforded two new epimeric eremophilane sesquiterpenoids, 7β‐ H‐3α‐angeloyloxy‐9‐ene‐11,12‐epoxy‐8‐oxoeremophilane ( 1 ) and 7α‐H‐3α‐angeloyloxy‐9‐ene‐11,12‐epoxy‐8‐oxoeremophilane ( 2 ), as well as four known sesquiterpenes, petasol ( 3 ), oplopanone ( 4 ), 4,5‐epoxy‐β‐caryophyllene ( 5 ), 4(15)‐eudesmene‐1β,6α‐diol ( 6 ), and three known monoterpenes, 1β,2α‐dihydroxy‐p‐menth‐5‐ene ( 7 ), 5α‐hydroxy‐2‐oxo‐p‐menth‐6(1)‐ene ( 8 ), 5β‐hydroxy‐2‐oxo‐p‐menth‐6(1)‐ene ( 9 ), and two known triterpenes, maniladiol 3‐O‐palmitate ( 10 ), taraxasteryl palmitate ( 11 ). The new compounds were characterized by means of spectroscopic methods including 1D, 2D NMR and HRESIMS, and the known ones were established on the basis of comparing their NMR data with those of the corresponding compounds in the literature. In addition, cytotoxicity against selected cancer cells (HL‐60, HO‐8910 and A‐549) of compounds 1 ‐ 4 , 6 , 7 , 10 were measured in vitro.     

An efficient route for synthesis of 5,6‐diphenylimidazo‐[2,1‐b]thiazoles as antibacterial agents

The reaction of 4,5‐diphenylimidazol‐2‐thione ( 1 ) with aromatic ketones 2a‐i using the acidified acetic acid method afforded the 4,5‐diphenyl(2‐imidazolylthio)acetophenones 3a‐h in good yields. While, the cyclized product 4i was obtained directly upon reaction of 1 with α‐acetyl naphthalene. Compounds 3a‐h were cyclized directly to the corresponding 3‐aryl‐5,6‐diphenylimidazo[2,1‐b]thiazoles (4a‐c) and ( 4e‐h ). In the same manner the reaction of 1 with aliphatic and/or alicyclic ketones gave the 3‐(4,5‐diphenyl‐2‐imidazolylthio)acetone derivatives 5a‐d , 2‐(4,5‐diphenylimidazolylthio)cycloalkanones 8a,d and the tricyclic compounds 9b‐c respectively. The cyclized compounds 6a‐d and 9a,d were obtained by cyclization of 5a‐d and 8a,b respectively. Oxidation of 1 gives the corresponding bis(4,5‐diphenyl‐2‐imidazolyl)‐disulfide ( 10 ) in 90% yield. Some of the synthesized compounds were tested for antifungal and antibacterial activity.     

Lignans from the Bark of Magnolia kobus

The Et₂O‐soluble fraction from the bark of Magnolia kobus led to the isolation of two new lignans, (+)‐(7α,7′α,8α,8′α)‐3′,4,4′,5,5′‐pentamethoxy‐7,9′: 7′,9‐diepoxylignan‐3‐ol ( 1 ) and (+)‐(7α,7′α,8α,8′α)‐4,5‐dimethoxy‐3′,4′‐(methylenedioxy)‐7,9′: 7′,9‐diepoxylignan‐3‐ol ( 2 ), along with five known lignans 3 – 7 . Their structures were established on the basis of various spectroscopic analyses including 1D‐ (¹H, ¹³C, and DEPT) and 2D‐NMR (COSY, NOESY, HMQC, and HMBC) and by comparison of their spectral data with those of related compounds.     

Synthesis,Photophysical, and Electrochemical Properties of RuII Polypyridyl Complexes Bridged with two Tetrapodal Symmetric and one Asymmetric Ligands

Two symmetric tetrapodal ligands L^1–2 and one asymmetric tetrapodal ligand L³ based on 4,5‐diazafluoren have been synthesized and characterized. Ligands L^1–2 formed by the condensation of pentaerythrityl tetratosylate with 4,5‐diazafluoren‐9‐oxime and 9‐(4‐hydroxy)phenylimino‐4,5‐diazafluorene, respectively. L³ was prepared by two steps, 9‐(4‐hydroxy)phenylimino‐4,5‐diazafluorene reacted with pentaerythrityl tetratosylate affording 1,1′,1"‐tris[(4,5‐diazafluoren‐9‐ylimino)phenoxymethyl]‐1"′‐(p‐tosyloxymethyl)‐methane, which reacted with 4,5‐diazafluoren‐9‐oxime affording the asymmetric ligand L³. Three tetranuclear Ru^II complexes [(bpy)₈L^1–3Ru₄](PF₆)₈ (bpy = bipyridine) were obtained by the reaction of Ru(bpy)₂Cl₂ · 2H₂O with ligands L^1–3. Spectroscopic studies of these complexes exhibit metal‐to‐ligand charge transfer absorptions at 440–445 nm and emissions at 575–579 nm. The electrochemical behaviors of these complexes are consistent with one Ru^II‐based oxidation couple and three ligand‐centered reduction couples.