Display options:
Normal
Show Abstracts
Compact
Displaying article 1-10
p. 661-665
Received: 28 July 2006; in revised form: 11 August 2006 / Accepted: 30 August 2006 / Published: 4 September 2006
Show/Hide Abstract
| Download PDF Full-text (60 KB) 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.
p. 666-676
Received: 9 August 2006; in revised form: 5 September 2006 / Accepted: 5 September 2006 / Published: 6 September 2006
Show/Hide Abstract
| Download PDF Full-text (178 KB) 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, 1 H-NMR, 13 C- and 31 P-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.
p. 677-683
Received: 12 August 2006; in revised form: 31 August 2006 / Accepted: 31 August 2006 / Published: 7 September 2006
Show/Hide Abstract
| Download PDF Full-text (73 KB) 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 for the first time.
p. 684-692
Received: 31 July 2006; in revised form: 28 August 2006 / Accepted: 29 August 2006 / Published: 13 September 2006
Show/Hide Abstract
| Download PDF Full-text (321 KB) 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.
p. 693-699
Received: 25 July 2006; in revised form: 28 August 2006 / Accepted: 30 August 2006 / Published: 13 September 2006
Show/Hide Abstract
| Download PDF Full-text (174 KB) 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) 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.
p. 700-706
Received: 13 August 2006; in revised form: 6 September 2006 / Accepted: 14 September 2006 / Published: 14 September 2006
Show/Hide Abstract
| Download PDF Full-text (67 KB) 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 in an overall yield of 35 % over eight steps without resorting to chromatographic purification.
p. 707-713
Received: 7 September 2006; in revised form: 14 September 2006 / Accepted: 14 September 2006 / Published: 18 September 2006
Show/Hide Abstract
| Download PDF Full-text (52 KB) 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.
p. 714-719
Received: 9 November 2005; in revised form: 27 September 2006 / Accepted: 28 September 2006 / Published: 28 September 2006
Show/Hide Abstract
| Download PDF Full-text (57 KB) 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.
p. 720-725
Received: 5 September 2005; in revised form: 7 June 2006 / Accepted: 30 June 2006 / Published: 28 September 2006
Show/Hide Abstract
| Download PDF Full-text (49 KB) 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 under mild conditions with excellentyields in short times by a heterogeneous wet TSA/KMnO4 in dichloromethane system.
p. 726-730
Received: 28 July 2006; in revised form: 30 August 2006 / Accepted: 21 September 2006 / Published: 28 September 2006
Show/Hide Abstract
| Download PDF Full-text (74 KB) Abstract: 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).
Displaying article 1-10
Plain Text
BibTeX
BibTeX (without abstracts)
Endnote
Endnote (without abstracts)
Tab-delimited
PubMed XML
DOAJ XML
AGRIS XML
to open them.