Publications by authors named "Chinh Pham The"

Two new compounds, named eudesm-4(15),7-diene-3α,9β,11-triol (1) and eudesm-4(15),7-diene-1β,3α,9β,11-tetraol (2) together with three known sesquiterpene lactones (1S,5R,7R,10R)-secoatractylolactone (3), (1S,5R,7R,10R)-secoatractylolactone-11-O-β-D-glucopyranoside (4) atractylenolide III (5) were isolated from the rhizomes of Atractylodes macrocephala. Their structures were elucidated by using one-dimensional (1D) and 2D-NMR spectra and high resolution electrospray ionization (HR-ESI)-MS data. Compound 5 exhibited the most active anti-inflammatory activity with IC values of 27.

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Three new chromanes, malloapeltas J-L (-), and one new flavone -glycoside, malloflavoside (), together with four known compounds, apigenin 6---D-xylopyranosyl-8---L-arabinopyranoside (), apigenin 6---D-glucopyranosyl-8---L-arabinopyranoside (), apigenin 7---D-apiofuranosyl-(1→2)--D-glucopyranoside (), and acantrifoside E () were isolated from the methanol extract of the leaves of . Their chemical structures were determined using spectroscopic methods, including 1D, 2D NMR, and HR-ESI-MS methods. All the isolated compounds were evaluated their cytotoxic activity against human prostate cancer (PC-3) and human breast cancer (MCF-7) cells, but none of them showed cytotoxicities on both human cancer cell lines.

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A new muurolane-type sesquiterpene, a new flavone arabinofuranoside derivative, and other five known flavone arabinofuranoside derivatives were isolated from the leaves of (Annonaceae family). Their chemical structures were determined to be (1,6,7)-muurola-4,10(14)-diene-15-ol (), quercetin 3---D-apiofuranosyl-(1→2)--L-arabinofuranoside (), quercetin 3---L-rhamnopyranosyl-(1→2)--L-arabinofuranoside (), quercetin 3---L-arabinofuranoside (), kaempferol 3---D-apiofuranosyl-(1→2)--L-arabinofuranoside (), kaempferol 3---L-rhamnopyranosyl-(1→2)--L-arabinofuranoside (), and kaempferol 3---L-arabinofuranoside () by analyses of HR-ESI-MS and NMR spectral data. Compounds and containing monosaccharide, arabinofuranoside, potentially inhibited NO productions in LPS activated RAW264.

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Mallotusapelta(Lour.) Müll.Arg has been used in traditional medicine for the treatment of chronic hepatitis.

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Dihydroartemisinin was converted to its corresponding alkyne-functionalized esters, which were subsequently deployed as substrates for a 'click' chemistry-mediated coupling-with 3'-azido-3'-deoxythydimine (AZT) to furnish novel triazole-artesunate-AZT hybrid compounds. Moreover, various substituted triazole-artemisinin :hybrids were synthesized based on 'click' chemistry between propargyl-substituted derivatives and artemisinin containing a 2-hydroxypropane unit. Fourteen new hybrids were thus successfully prepared and evaluated as cytotoxic agents, revealing an interesting anticancer activity of four triazole-artemisinin derivative hybrids in KB and HepG2 cancer cell lines.

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The synthesis of various substituted triazole-indenoisoquinoline hybrids was performed based on a CuI-catalyzed 1,3-cycloaddition between propargyl-substituted derivatives and the azide-containing indenoisoquinoline. Besides, a variety of N-(alkyl)propargylindenoisoquinolines was used as substrates for the construction of triazole-indenoisoquinoline-AZT conjugated via a click chemistry-mediated coupling with 3'-azido-3'-deoxythymidine (AZT). Thus, twenty three new indenoisoquinoline-substituted triazole hybrids were successfully prepared and evaluated as cytotoxic agents, revealing an interesting anticancer activity of four triazole linker-indenoisoquinoline-AZT hybrids in KB and HepG2 cancer cell lines.

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1,4-Dihydroxy-2-naphthoic acid was used as a substrate for a straightforward five-step synthesis of 3-substituted 1H-benzo[g]isochromene-5,10-diones, with a Michael addition of N-acylmethylpyridinium ylides across 2-hydroxymethyl-1,4-naphthoquinone and a subsequent acid-mediated dehydratation of intermediate hemiacetals as the key steps. The obtained benzo[g]isochromene-5,10-diones were subsequently deployed for further synthetic elaboration to produce new 3,4-dihydrobenzo[g]isochromene-5,10-diones and (3,4-dihydro-)4a,10a-epoxybenzo[g]isochromene-5,10-diones. All compounds were screened for their cytotoxic and antimicrobial effects, revealing an interesting cytotoxic activity of 1H-benzo[g]isochromene-5,10-diones against different cancer cell lines.

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Betulinic acid and analogous naturally occurring triterpenoid acids were transformed into the corresponding propargyl esters and subsequently deployed as substrates for a click chemistry-mediated coupling with azidothymidine (AZT) en route to novel 1,2,3-triazole-tethered triterpenoid-AZT conjugates. Twelve new hybrids were thus prepared and assessed in terms of their cytotoxic activity, revealing an interesting anticancer activity of five triterpenoid-AZT hybrids on KB and Hep-G2 tumor cell lines.

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In this Letter, we report a convenient and efficient method for the synthesis of new simplified derivatives of hemiasterlin in which the α,α-dimethylbenzylic moiety A is replaced by α,β-unsaturated aryl groups as Michael acceptor. Most of these derivatives have a strong cytotoxic activity on three human tumor cell lines (KB, Hep-G2 and MCF7). Analogs 17b and 17f showed a high cytotoxicity against KB and Hep-G2 cancer cell lines comparable to paclitaxel and ellipticine.

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A five-step procedure for the synthesis of cis-1-tosyl-2-tosyloxymethyl-3-(trifluoromethyl)aziridine was developed, starting from 1-ethoxy-2,2,2-trifluoroethanol, involving imination, aziridination, ester reduction, hydrogenation, and N-,O-ditosylation steps. Further synthetic elaborations revealed a remarkable difference in the reactivity of cis-1-tosyl-2-tosyloxymethyl-3-(trifluoromethyl)aziridine with respect to aromatic sulfur and oxygen nucleophiles, thus enabling the selective deployment of this versatile substrate as a building block for the synthesis of functionalized aziridines, azetidines, and benzo-fused dithianes, oxathianes, dioxanes, and (thio)morpholines.

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A convenient approach toward nonactivated 1-alkyl-2-(trifluoromethyl)azetidines as a new class of constrained azaheterocycles was developed starting from ethyl 4,4,4-trifluoroacetoacetate via imination, hydride reduction, chlorination, and base-induced ring closure. Furthermore, the reactivity profile of these 2-CF(3)-azetidines was assessed by means of quaternization and subsequent regiospecific ring opening at C4 of the azetidinium intermediates by oxygen, nitrogen, carbon, sulfur, and halogen nucleophiles, pointing to a clear difference in reactivity compared to azetidines bearing other types of electron-withdrawing groups at C2.

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