Molecules

74 KiB

Open AccessCommunication

Synthesis of New N-Quaternary-3-benzamidoquinuclidinium Salts

by Renata Odzak and Srdjanka Tomic

Molecules 2006, 11(9), 726-730; https://doi.org/10.3390/11090726 - 28 Sep 2006

Cited by 3 | Viewed by 7067

The synthesis of racemic and enantiomerically pure N-p-methylbenzyl-3- and N-p-chlorobenzylbenzamidoquinuclidinium bromides (6-8 and 9-11, respectively) is described. These compounds were prepared from racemic or enantiomerically pure 3-benzamidoquinuclidines 3-5 using the appropriate quaternization reagents: p-methyl- benzyl bromide (1) and p-chlorobenzyl bromide (2). Full article

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49 KiB

Open AccessCommunication

Tungstate Sulfuric Acid (TSA)/ KMnO₄ as a Novel Heterogeneous System for Rapid Deoximation

by Bahador Karami and Morteza Montazerozohori

Molecules 2006, 11(9), 720-725; https://doi.org/10.3390/11090720 - 28 Sep 2006

Cited by 27 | Viewed by 7920

Abstract

Neat chlorosulfonic acid reacts with anhydrous sodium tungstate to givetungstate sulfuric acid (TSA), a new dibasic inorganic solid acid in which two sulfuricacid molecules connect to a tungstate moiety via a covalent bond. A variety of oximeswere oxidized to their parent carbonyl compounds [...] Read more.

Neat chlorosulfonic acid reacts with anhydrous sodium tungstate to givetungstate sulfuric acid (TSA), a new dibasic inorganic solid acid in which two sulfuricacid molecules connect to a tungstate moiety via a covalent bond. A variety of oximeswere oxidized to their parent carbonyl compounds under mild conditions with excellentyields in short times by a heterogeneous wet TSA/KMnO₄ in dichloromethane system. Full article

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57 KiB

Open AccessArticle

Glycerolipids from a Sarcotragus Species Sponge

by Yonghong Liu, Jee H. Jung, Hong Ji and Si Zhang

Molecules 2006, 11(9), 714-719; https://doi.org/10.3390/11090714 - 28 Sep 2006

Cited by 19 | Viewed by 8096

Abstract

One known and two new glycerolipids have been isolated from a Sarcotragus sp. marine sponge. The gross structures were established based on NMR and MS analysis. Full article

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52 KiB

Open AccessArticle

Asymmetric Synthesis of (7aS)-7a-Methyl-4,5,7,7a-tetrahydro-1H-indene-2,6-dione and Useful Derivatives Thereof

by Samuël Demin, Dirk Van Haver and Pierre J. De Clercq

Molecules 2006, 11(9), 707-713; https://doi.org/10.3390/11090707 - 18 Sep 2006

Viewed by 8791

Abstract

The enantioselective synthesis of the title compound, using Meyers' bicyclic lactam methodology, is described. This compound and a few of its derivatives are useful intermediates in natural product synthesis. Full article

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67 KiB

Open AccessArticle

An Efficient Synthesis of a Spirocyclic Oxindole Analogue

by Dawei Teng, Hongxing Zhang and A. Mendonca

Molecules 2006, 11(9), 700-706; https://doi.org/10.3390/11090700 - 14 Sep 2006

Cited by 14 | Viewed by 8444

Abstract

An efficient, scaleable synthesis approach towards the spirocyclic oxindole analogue 1’-(tert-butoxycarbonyl)-2-oxospiro[indoline-3,4’-piperidine]-5-carboxylic acid (1) is described. The key steps are dianion alkylation and cyclization of ethyl 2- oxindoline-5-carboxylate (4) and demethylation of the resulting spirocyclic oxindole ethyl 1’-methyl-2-oxospiro[indoline-3,4’-piperidine]-5-carboxylate (5). The target compound was obtained [...] Read more.

An efficient, scaleable synthesis approach towards the spirocyclic oxindole analogue 1’-(tert-butoxycarbonyl)-2-oxospiro[indoline-3,4’-piperidine]-5-carboxylic acid (1) is described. The key steps are dianion alkylation and cyclization of ethyl 2- oxindoline-5-carboxylate (4) and demethylation of the resulting spirocyclic oxindole ethyl 1’-methyl-2-oxospiro[indoline-3,4’-piperidine]-5-carboxylate (5). The target compound was obtained in an overall yield of 35 % over eight steps without resorting to chromatographic purification. Full article

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174 KiB

Open AccessCommunication

Cytotoxicity of Two Triterpenoids from Nigella glandulifera

by Ze Tian, Yu-Ming Liu, Si-Bao Chen, Jun-Shan Yang, Pei-Gen Xiao, Liao Wang and Erxi Wu

Molecules 2006, 11(9), 693-699; https://doi.org/10.3390/11090693 - 13 Sep 2006

Cited by 44 | Viewed by 11229

Abstract

During an investigation of antitumor substances from Nigella glandulifera Freyn et Sint. (Ranunculaceae) the cytotoxicity of two oleanane triterpene saponins isolated from the seeds of this species, kalopanaxsaponins A and I, was evaluated against HepG2, drug resistant HepG2 (R-HepG2) (two hepatocyte cell lines) [...] Read more.

During an investigation of antitumor substances from Nigella glandulifera Freyn et Sint. (Ranunculaceae) the cytotoxicity of two oleanane triterpene saponins isolated from the seeds of this species, kalopanaxsaponins A and I, was evaluated against HepG2, drug resistant HepG2 (R-HepG2) (two hepatocyte cell lines) and primary cultured normal mouse hepatocytes. Evident cytotoxic activities were observed. Morphological observations and cell cycle analysis suggest that these compounds inhibit the proliferation of hepatoma by inducing apoptosis and consequently kalopanaxsaponins A and I may be potential therapeutic agents for the treatment of parental and drug resistant hepatoma. Full article

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321 KiB

Open AccessArticle

Synthesis and Characterisation of Eight Isomeric Bis(2-pyridyloxy)naphthalenes

by Brendan J. O’Keefe and Peter J. Steel

Molecules 2006, 11(9), 684-692; https://doi.org/10.3390/11090684 - 13 Sep 2006

Cited by 3 | Viewed by 7486

Abstract

Eight isomeric bis(2-pyridyloxy)naphthalenes have been prepared from reactions of 2-bromopyridine with the appropriate dihydroxynaphthalene and the products fully characterised by 1- and 2-D NMR spectroscopy. Full article

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73 KiB

Open AccessArticle

Cerebrosides from the Roots of Serratula chinensis

by Tiejun Ling, Tao Xia, Xiaochun Wan, Daxiang Li and Xiaoyi Wei

Molecules 2006, 11(9), 677-683; https://doi.org/10.3390/11090677 - 07 Sep 2006

Cited by 23 | Viewed by 10847

Abstract

A new cerebroside, 1-O-β-D-glucopyranosyl-(2S,3R,8E)-2-[(2’R)-2-hydroxy- palmitoylamino]-8-octadecene-1,3-diol, along with aralia cerebroside and 1-O-β-D- glucopyranosyl-(2S,3S,4R,8E)-2-[(2’R)-2-hydroxybehenoylamino]-8-octadecene-1,3,4-triol were isolated from the roots of Serratula chinensis S. Moore. The structure of the new cerebroside was established by spectroscopic and chemical means. Occurrence of cerebrosides in Serratula is reported here [...] Read more.

A new cerebroside, 1-O-β-D-glucopyranosyl-(2S,3R,8E)-2-[(2’R)-2-hydroxy- palmitoylamino]-8-octadecene-1,3-diol, along with aralia cerebroside and 1-O-β-D- glucopyranosyl-(2S,3S,4R,8E)-2-[(2’R)-2-hydroxybehenoylamino]-8-octadecene-1,3,4-triol were isolated from the roots of Serratula chinensis S. Moore. The structure of the new cerebroside was established by spectroscopic and chemical means. Occurrence of cerebrosides in Serratula is reported here for the first time. Full article

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178 KiB

Open AccessArticle

Synthesis and Antiviral Bioactivities of α-Aminophosphonates Containing Alkoxyethyl Moieties

by Yingshu Xu, Kai Yan, Baoan Song, Gangfang Xu, Song Yang, Wei Xue, Deyu Hu, Ping Lu, Guiping Ouyang, Linhong Jin and Zhuo Chen

Molecules 2006, 11(9), 666-676; https://doi.org/10.3390/11090666 - 06 Sep 2006

Cited by 86 | Viewed by 11965

Abstract

A simple, efficient, and general method has been developed for the synthesis ofvarious α-aminophosphonate derivatives 4a-4l by treatment of substituted benzaldehydes andaniline with bis(2-methoxyethyl)- or bis(2-ethoxyethyl) phosphite under microwaveirradiation without solvents and catalysts. The products were characterized by elementalanalysis, IR, ¹H-NMR, ¹³ [...] Read more.

A simple, efficient, and general method has been developed for the synthesis ofvarious α-aminophosphonate derivatives 4a-4l by treatment of substituted benzaldehydes andaniline with bis(2-methoxyethyl)- or bis(2-ethoxyethyl) phosphite under microwaveirradiation without solvents and catalysts. The products were characterized by elementalanalysis, IR, ¹H-NMR, ¹³C- and ³¹P-NMR spectra. The X-ray crystallographic data of therepresentative compound 4l was determined. The new α-aminophosphonate derivatives werefound to possess moderate to good antiviral activity. Full article

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60 KiB

Open AccessCommunication

A Novel Triterpene from Centella asiatica

by Quan-Lin Yu, Hong-Quan Duan, Yoshihisa Takaishi and Wen-Yuan Gao

Molecules 2006, 11(9), 661-665; https://doi.org/10.3390/11090661 - 04 Sep 2006

Cited by 31 | Viewed by 10167

Abstract

A novel triterpene, 2α,3β,20,23-tetrahydroxyurs-28-oic acid (1), was isolated from the aerial part of Centella asiatica. Its structure was elucidated by spectroscopic methods, including 2D-NMR spectra. It displayed no activity against Hela and A549 cell lines at concentrations of 10 and 30 μg/mL, respectively. [...] Read more.

A novel triterpene, 2α,3β,20,23-tetrahydroxyurs-28-oic acid (1), was isolated from the aerial part of Centella asiatica. Its structure was elucidated by spectroscopic methods, including 2D-NMR spectra. It displayed no activity against Hela and A549 cell lines at concentrations of 10 and 30 μg/mL, respectively. Full article

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Molecules, Volume 11, Issue 9 (September 2006) – 10 articles , Pages 661-730

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