A concise, stereoselective synthesis of the trans-hydrindane core of the marine natural product dictyoxetane is reported, starting from a Robinson annelation derived bicyclic enone. A phosphorane-mediated, pinacol-like rearrangement of a cis-diol, via a formal 1,2-hydride shift, is used to establish the requisite trans ring junction. (31)P NMR supports the formation ...

A new benzophenone C-glycoside, malaferin A (1), and two new epicatechin derivatives, malaferin B (2) and malaferin C (3), together with five known compounds were isolated from Malania oleifera. In addition, (-)-epicatechin-3-O-benzoate (6) was isolated for the first time from a natural resource. Structures of 1-3 were determined on the ...

A new sesquiterpene lactone, named tomenphantopin H (1), together with two known germacranolides, 2β-methoxy-2-deethoxy-8-O-deacylphantomolin-8-O-tiglinate (2) and 2-deethoxy-2-hydroxyphantomolin (3), was isolated from the whole plant of Elephantopus tomentosus Linn. The new compound was completely elucidated using a combination of 1D and 2D NMR techniques (COSY, HMQC, and HMBC) and HR-ESI-MS analyses. ...

1α-acetoxy-5α, 7β-dihydroxycassa-11,13(15)-diene-16,12-lactone, a new cassane-type diterpene was isolated from Caesalpinia crista. The structure of this compound was elucidated by analysis of NMR spectra, and the relative configuration was established by NOE experiment. The new compound was evaluated for antitumour activity against T47D, DU145 and showed significant inhibitory activities.

A new drimane sesquiterpene, 1α,7α-dihydroxyconfertifolin (1), along with two known compounds 2 and 3, was isolated from endophytic fungus A12 of Dracaena cambodiana. The new compound was elucidated by HR-ESI-MS and spectroscopic techniques (IR, UV, 1D, and 2D NMR). Compound 2 showed inhibitory bacterial activity against Staphylococcus aureus with diameter ...

Anti-Markovnikov additions to non-conjugated unsaturated amines in superacid are reported. In situ NMR studies, DFT calculations and labelled substrates reactions support the involvement of new ammonium-carbenium superelectrophiles in this original process.

Two new taxoids (5 and 6) were obtained by isolating impurities in aziditaxel, and their structures were characterized based on data analysis of (1)H NMR, (13)C NMR, HPLC-MS, and through comparison with literature. In order to test their cytotoxicities against human nonsmall lung cancer cell lines (A549), sufficient amounts of ...

A new xanthone, calothorexanthone, together with five known compounds, garbogiol, 1,4,8-trihydroxyxanthone, δ-tocotrienol, 1,7-dihydroxyxanthone and globuxanthone, was isolated from a petroleum ether extract of the bark of Calophyllum thorelii. Their structures were established on the basis of spectroscopic methods, mainly one- and two-dimensional NMR. Antioxidant activity of the isolated compounds was ...

In the present study, a series of (Z)-N-(1-[2-{3-[(dimethylamino)methyl)]-2-methoxyphenyl}-5-(pyridin-4-yl)-1,3,4-oxadiazol-3(2H)-yl]ethylidene)benzenamine derivatives have been synthesized and characterized by IR, 1H NMR and 13C NMR spectra. All the synthesized compounds were evaluated for their antifungal activity and were compared with the standard drug, clotrimazole. The compounds demonstrated excellent to weak antifungal activity. Among the ...

Tropane, tropinone, pseudopelletierine and cocaine were oxidized in situ in a nuclear magnetic resonance (NMR) tube providing mixtures of exo/endo N-oxides. Observed (13) C chemical shifts were correlated with values calculated by gauge-including atomic orbitals density functional theory (DFT) OPBE/6-31G* method using DFT B3LYP/6-31G* optimized geometries. The same method of ...

We set out to describe an efficient and versatile method for preparing pentacyclic steroids diversely substituted at C-11 from cholic acid, via a stereoselective epoxidation and the epoxide opening as the key steps. The characteristic (1)H and (13)C NMR spectroscopic features of the synthesized compounds are reported.

The solvation of CO2 in 1-butyl-3-methylimidazolium acetate (Bmim Ac) has been investigated by 1H, 13C and 15N NMR spectroscopy at low CO2 molar fraction (xCO2 c.a. 0.27) corresponding to the reactive regime described in part I of this study. It is shown that a carboxylation reaction occurs between CO2 and ...

Abstract Background. A multicomponent evaluation of the oxidative consumption of salivary biomolecules by a tooth-whitening oral rinse preparation has been performed using high-resolution proton ((1)H) nuclear magnetic resonance spectroscopy (NMR). Methods. Unstimulated human saliva samples (n = 12) were treated with aliquots of the oral rinse tested and 600 MHz ...

Nucleophilic substitution reactions of N(3)P(3)Cl(4)[O(CH(2))(2)NCH(3)], () with the sodium salts of mono- and di-functional alcohols [methanol (), phenol (), tetraethyleneglycol () and 1,3-propanediol ()] were carried out in order to investigate a possible directing effect of the spiro O-moiety on the formation of mono-substituted (, ), non-geminal di-substituted (, ) ...

Nine new fungal metabolites, one phthalide derivative, acremonide (1), and eight isocoumarin derivatives, acremonones A-H (2-9), were isolated from the mangrove-derived fungus Acremonium sp. PSU-MA70 together with 10 known compounds. Their structures were determined by NMR analysis. The known 8-deoxytrichothecin and trichodermol exhibited moderate antifungal activity against Candida albicans and ...

A highly stereoselective synthesis of α- or β-glycofuranosyl amides based on the traceless Staudinger ligation of glycofuranosyl azides of the galacto, ribo, and arabino series with 2-diphenylphosphanyl-phenyl esters has been developed. Both α- and β-isomers can be obtained with excellent selectivity from a common, easily available precursor. The process does ...

Five new cycloartane triterpenoids, schiglausins K-O (1-5), including one hexanortriterpenoid (1) and one octanortriterpenoid (2), as well as two known compounds (6-7), were isolated from the stems of Schisandra glaucescens Diels. Their structures were elucidated on the basis of spectroscopic methods, including extensive NMR spectra. Compounds 2-7 were tested for ...

A highly improved one-pot procedure for the synthesis of diazepinones, which incorporate a bioactive quinoline nucleus, under catalyst-, and solvent-free environment has been developed. The method allowed us to achieve the products in high yields without requiring a chromatographic separation. All new quinolyldibenzo[b,e][1,4]diazepinones 6a-h thus obtained were further treated to ...

We report the first one-pot process for the asymmetric addition of allyl, methallyl, and propargyl groups to aldehydes and ketones using B-chlorodiisopinocampheylborane (dDIP-Cl) and indium metal. Under Barbier-type conditions, indium metal was used to generate allyl- and allenylindium intermediates, and subsequent reaction with dDIP-Cl successfully promoted the transfer of these ...

A phytochemical investigation of the aerial parts of Cephalaria elmaliensis resulted in the isolation of ten hederagenin-type triterpene saponins (1-10) including three new ones, elmalienoside A (1), elmalienoside B (2), elmalienoside C (3), and two known flavonoid glycosides (11-12). Their structures were identified by extensive spectroscopic techniques (1D and 2D ...

ABSTRACT: BACKGROUND: Ralstonia solanacearum, one of the most important bacterial diseases on plants, is a devastating, soil-borne plant pathogen with a global distribution and an unusually wide host range. In order to discover new bioactive molecules and pesticides acting on tobacco bacterial wilt, we sought to combine the active structure ...

On account of the reported anticancer activity of pyrazoles and oxadiazoles, we have designed and synthesized a novel combinatorial library of S-substituted-1,3,4-oxadiazole bearing N-methyl-4-(trifluoromethyl)phenyl pyrazole moiety and tested for in-vitro cytotoxic activity by MTT assay. Amongst the tested compounds, the compound 5e was the most promising anticancer agent with IC(50) ...

The electrosynthetic method has been used to selectively synthesize fullerene derivatives that are otherwise not accessible by other procedures. Recent attempts to electrosynthesize Sc3N@Ih-C80 derivatives using the Sc3N@Ih-C80 dianion were unsuccessful due to its low nucleophilicity. Those results prompted us to prepare the Sc3N@C80 trianion which should be more nucleophilic ...

Cultivation of Cordyceps indigotica, an entomopathogenic fungus, in the presence of suberoyl bis-hydroxamic acid (an HDAC inhibitor) greatly activated its polyketide synthesis apparatus to afford six novel aromatic polyketides, indigotides C-F (1-4), 13-hydroxyindigotide A (5), and 8-O-methylindigotide B (6). The structures of these compounds were determined by NMR spectroscopic analyses. ...

Inspired by β-CD, a macrocyclic oligomers of d-(+)-glucopyranose and a renewable material, which could be obtained from starch, that can promote a lot of organic reactions in water, a green solvent, several amino alcohol-modified β-CDs CD-1 to CD-7 were synthesized in the yields of 36-61%. Their conformations in vacuum and ...

The first total synthesis of 6'-hydroxyjusticidin A, isolated from Justicia procumbens L. with good inhibitory activity against cancer cells, has been accomplished. The structure was confirmed by (1)H NMR, (13)C NMR, and HR-ESI-MS. The key steps involved a Diels-Alder cycloaddition reaction and a reduction in NaBH(4).

A metal-free tandem Friedel-Crafts/Lactonization reaction to 3,3-diaryl or 3-alkyl-3-aryl benzofuranones catalyzed by HClO4 was reported. A variety of tertiary α-hydroxy acid esters could readily react with substituted phenols to afford the desired products in rich diversity. The synthetic utility of the products was demonstrated by the synthesis of polycyclic compounds. ...

The synthesis of sublancin 168, a unique S-glucosylated bacteriocin antibiotic, is described. The natural product and two S-glycosylated variants were successfully prepared via native chemical ligation followed by folding. The synthetic glycopeptides were shown to possess primarily an α-helical secondary structure by CD and NMR studies.

To affiliate multiple bioactivities in a compact heteronuclei, two series of benzimidazole based 1,3,4-oxadiazoles were synthesized and assessed in vitro for their efficacy as antimicrobial agents against eight bacteria (Staphylococcusaureus, Bacilluscereus, Escherichiacoli, Pseudomonasaeruginosa, Klebsiellapneumoniae, Salmonellatyphi, Proteusvulgaris, Shigellaflexneri), four fungi (Aspergillusniger, Aspergillusfumigatus, Aspergillusclavatus, Candidaalbicans) and Mycobacterium tuberculosis H37Rv and best results were ...

Unrestricted: Pseudoephenamine is introduced as a versatile chiral auxiliary and an alternative to pseudoephedrine in asymmetric synthesis. It is free from regulatory restrictions and leads to remarkable stereocontrol in alkylation reactions, especially in those that form quaternary carbon centers. Amides derived from pseudoephenamine exhibit a high propensity to be crystalline ...

Lipase-catalyzed acylation of Guanfu alcohol-amine (GFAA) with vinyl acetate (VA) was performed in non-aqueous system for the preparation of Guanfu base G (GFG), a plant-originated alkaloid with significant antiarrhythmic activity. Among the eight lipases from different origins, Novozym 435 was found to be the best biocatalyst. The most suitable molecular ...

We describe the synthesis of a series of oxy-substituted butenolide spiroacetals and spiro-N,O-acetals by oxidative spirocyclisation of 2-[(4-hydroxy or 4-sulfonamido)butyl]furans. The axial-equatorial preference of each oxy-substituent is investigated (NMR) by an acid-catalysed thermodynamic relay of configuration between the spiro- and oxy-centres. The axial site is preferred for most oxy-substituents at ...

Three new phenolic compounds, nicotphenols A-C (1-3), together with 14 known phenols (4-17), were isolated from the leaves of Nicotiana tabacum. Their structures were established by means of spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1-3 were tested for their anti-HIV-1 activities and cytotoxicities. They all showed ...

Two novel aromatic glucosides, named marylaurecinosides B (1) and C (2), were isolated from Cymbidium Great Flower Marie Laurencin, together with six known aromatic compounds (3-8). These structures were determined on the basis of NMR experiments as well as chemical evidence. All of the isolated compounds (1-8) were tested for ...

Thirty-nine fungal metabolites 1-39, including two new alkaloids, 12β-hydroxy-13α-methoxyverruculogen TR-2 (6) and 3-hydroxyfumiquinazoline A (16), were isolated from the fermentation broth of Aspergillus fumigatus LN-4, an endophytic fungus isolated from the stem bark of Melia azedarach. Their structures were elucidated on the basis of detailed spectroscopic analysis (mass spectrometry and ...

A phytochemical investigation of the whole plants of CASSIA OCCIDENTALIS led to the isolation of two new cycloartane triterpenoids, cycloccidentalic acids A and B ( 1 and 2), and five new related saponins, cycloccidentalisides I-V ( 3- 7), together with sixteen known compounds. The structures of the isolated compounds were ...

Three new mycophenolic acid derivatives, penicacids A-C (1-3), together with two known analogues, mycophenolic acid (MPA, 4) and 4'-hydroxy-MPA (5), were isolated from a fungus Penicillium sp. SOF07 derived from a South China Sea marine sediment. The structures of compounds 1-3 were elucidated on the basis of MS and NMR ...

Chemical investigation of low polar solvent extract of Salix caprea through chromatographic techniques led to the isolation of new triterpene as 1α,3β,25-trihydroxy-9(11)-ene-16-one-9,10-seco-9,19-cyclolanostane (1) along with fatty alcohols. The structure of compound 1 was established by IR, HRESI/MS and NMR including 1D and 2D experiments. The compound 1 showed moderate in vitro ...

The present study describes a convenient method for the synthesis of new lipoxygenase inhibitors, 4-(toluene-4-sulfonylamino)-benzoic acids from p-amino benzoic acid. Reaction of p-amino benzoic acid with p-toluenesulfonyl chloride provided thirteen N- and O-alkylation products 4a-4m in moderate to good yields. Lipoxygenase inhibition of newly formed sulfonamide derivatives was investigated and ...

A cross-dehydrogenative coupling reaction of indolizines with electron-deficient alkenes for the synthesis of 3-alkenyl-substituted indolizines has been reported. The reaction takes place at the 3-position selectively through palladium-catalyzed CH activation, following a Heck-type cross-coupling reaction under mild and ligand-free conditions. Furthermore, the reaction mechanism of the Pd(II) /Pd(0) catalytic pathway ...

Although the composition of strawberry fruit has been extensively studied, especially for the most abundant phenolic compounds, agrimoniin has never been univocally identified as one of the most abundant phenolic compounds in the fruit. In this study agrimoniin was isolated in the fruit of Fragaria vesca and its structure characterized. ...

A new C-alkylated flavonoid (5,7-dihydroxy-3'-(4″-acetoxy-3″-methylbutyl)-3,6,4'-trimethoxyflavone (1), along with two known C-alkylated flavonoids (5,7-dihydroxy-3'-(3-hydroxymethylbutyl)-3,6,4'-trimethoxyflavone (2), 5,7,4'-trihydroxy-3'-(3-hyroxymethylbutyl)-3,6-dimethoxyflavone (3) and two new source C-alkylated flavonoids (5,7-dihydroxy-3'-(2-hydroxy-3-methyl-3-butenyl)-3,6,4'-trimethoxyflavone (4), 5,7,4'-trihydroxy-3,6-dimethoxy-3'-isoprenyl-flavone (5) were isolated from the aerial parts of Dodonaea viscosa. The structures of all compounds were established on the basis of 1D and 2D NMR ...

In the present study, (E)-2-{ [-2-(2,4-Dinitrophenyl)hydrazono]methyl} phenol (3) was synthesized and used as key intermediate for the synthesis of new Mannich bases. All the synthesized compounds were evaluated for their antifungal activity against three fungal strains Candida albicans, Candida tropicalis and Aspergillus niger and antioxidant activity. The structure of these ...

AmAZAing metallacycles: Azarhodacyclobutane was prepared by oxidation of Rh(I) -olefin complex 1 (see Scheme; Ts=p-toluenesulfonyl). Both isomers 2 a and 2 b were isolated and characterized by NMR spectroscopy and mass spectrometry; their configurations were unambiguously established by NOE experiments.

3,4-Dihydropyrimidinones of curcumin were synthesized in excellent yield by multi-component one-pot condensation of curcumin, substituted aromatic aldehydes and urea/thiourea under solvent free conditions using SnCl(2)·2H(2)O catalyst. All the synthesized compounds have been characterized by IR, (1)H NMR, (13)C NMR, Mass spectra as well as elemental analyses. The synthesized compounds 4a-n ...

DADB synthesis: The diammoniate of diborane (DADB) was synthesized in a new metathesis reaction between the diammoniate of monochloroborane and potassium borohydride in liquid ammonia. (1) H and (11) B NMR spectra of DADB are reported. The stability in THF was examined by variable-temperature (11) B NMR spectroscopy.

The post-functionalization of poly(3-hexylthiophene) (P3HT) via various synthetic routes is reported. Well-defined and monofunctionalized ω-thiol-terminated P3HT, ω-carboxylic acid-terminated P3HT, ω-acrylate-terminated P3HT, and ω-methacrylate-terminated P3HT are obtained in high yields through a straightforward procedure. From those, different novel P3HT-based graft copolymers are synthesized following two routes: "grafting onto" and "grafting through" ...

Three new sucrose esters (1-3) along with several known compounds were isolated from the fruits of Physalis solanaceus. The structural elucidation of the isolates was based on their spectroscopic characteristics mainly those of MS and NMR.

A series of novel methylene bis-isoxazolo[4,5-b]azepines have been synthesized by reaction of 3,5-dimethyl-4-nitroisoxazole 6 with an appropriate methylene bis-chalcones 7 to obtain various Michael adducts 8a-i, which on treatment with SnCl(2)-MeOH underwent reductive cyclization to afford the title compounds 9a-i. Structure of these compounds were established on the basis of ...

A phytotoxic root exudate from Acroptilon repens was identified as 7,8-benzoflavone, an inhibitor of cytochrome P450 1A2 and activator of cytochrome P450 3A4. The synthetic 5,6-benzoflavone also is a potent phytotoxin. Six 7,8-benzoflavones and eight 5,6-benzoflavones were synthesized in this study. The NMR data for a few of these compounds ...