- Dihydrochelerythrine and its derivatives: Synthesis and their application as potential G-quadruplex DNA stabilizing agents
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A convenient route was envisaged toward the synthesis of dihydrochelerythrine (DHCHL), 4 by intramolecular Suzuki coupling of 2-bromo-N-(2-bromobenzyl)-naphthalen-1-amine derivative 5 via in situ generated arylborane. This compound was converted to (±)-6-acetonyldihydrochelerythrine (ADC), 3 which was then resolved by chiral prep-HPLC. Efficiency of DHCHL for the stabilization of promoter quadruplex DNA structures and a comparison study with the parent natural alkaloid chelerythrine (CHL), 1 was performed. A thorough investigation was carried out to assess the quadruplex binding affinity by using various biophysical and biochemical studies and the binding mode was explained by using molecular modeling and dynamics studies. Results clearly indicate that DHCHL is a strong G-quadruplex stabilizer with affinity similar to that of the parent alkaloid CHL. Compounds ADC and DHCHL were also screened against different human cancer cell lines. Among the cancer cells, (±)-ADC and its enantiomers showed varied (15-48%) inhibition against human colorectal cell line HCT116 and breast cancer cell line MDA-MB-231 albeit low enantio-specificity in the inhibitory effect; whereas DHCHL showed 30% inhibition against A431 cell line only, suggesting the compounds are indeed cancer tissue specific.
- Malhotra, Rajesh,Rarhi, Chhanda,Diveshkumar,Barik, Rajib,D'Cunha, Ruhee,Dhar, Pranab,Kundu, Mrinalkanti,Chattopadhyay, Subrata,Roy, Subho,Basu, Sourav,Pradeepkumar,Hajra, Saumen
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p. 2887 - 2896
(2016/06/13)
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- Pd-catalyzed direct arylation approach to the 6H-dibenzo[c,h]chromenes: Total synthesis of arnottin I
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An efficient synthesis of 6H-dibenzo[c,h]chromenes has been achieved from 2-bromobenzyl-α-naphthyl ethers via a Pd-catalyzed Intramolecular direct-arylation using easily available Pd(PPh3)4 or Pd(OAc)2/PPh3 at elevated temperature. The reaction affords biaryl-coupling products in good to excellent yields in 6-9 h (up to 94% yields). A tentative mechanism has been proposed to understand the reaction pathway. Applying the methodology, a straightforward and concise total synthesis of arnottin I has been demonstrated by converting the biaryl-coupling products to the 6H-benzo[d]naphtho[1,2-b]pyran-6-one using pyridinium chlorochromate (PCC) mediated oxidation.
- De, Subhadip,Chaudhuri, Saikat,Mishra, Sourabh,Mamtani, Himanshu,Bisai, Alakesh
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p. 1871 - 1884
(2014/01/17)
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- The total synthesis of salvianolic acid F
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An expeditious synthesis of salvianolic acid F 2 is described in 10% overall yield. Tetramethyl salvianolic acid F 3 was obtained in six steps in 39% overall yield and was converted into the target molecule using boron tribromide in 26% yield.
- Dalla, Vincent,Cotelle, Philippe
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p. 6923 - 6930
(2007/10/03)
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- Synthesis of linear oligo(catechol) ligands for the metal directed self-assembling of helicates
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The synthesis of the oligo(catechol) systems 1-4 with different substituents, length of the connecting spacer, and number of catechol units is achieved by the use of various coupling reactions (e.g. Wurtz, Glaser-Eglinton, Stephens-Castro). In order to do this methods of preparing the building blocks, 2,3-dimethoxybenzyl bromides 5, 2,3-dimethoxyphenylacetylene (17), or 1,4-dibromo-2,3-dimethoxybenzene (23) have been developed starting with simple catechol (benzene-1,2-diol) derivatives.
- Albrecht, Markus
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p. 230 - 236
(2007/10/03)
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