| 1. |
- Almqvist, Fredrik, et al.
(author)
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Spirobicyclo[2.2.2]octane derivatives: mimetics of baccatin III and paclitaxel (Taxol)
- 2004
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In: Organic & Biomolecular Chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 2:21, s. 3085-3090
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Journal article (peer-reviewed)abstract
- The formylated spirobyclic alcohol 8a was computer modeled to be a mimetic of paclitaxel. In this model, the formyl group was used as a truncated paclitaxel side chain in order to reduce the computational work. Compound 8c, carrying the paclitaxel side chain, was synthesized in six steps from optically active 1,3-diketone 12. Microtubule stabilization was not observed for 8c, indicating that the model needs to be adjusted.
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| 2. |
- Almqvist, Fredrik, et al.
(author)
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Spirobicyclo[2.2.2]octane derivatives: mimetics of baccatin III and paclitaxel (Taxol)
- 2004
-
In: ORGANIC & BIOMOLECULAR CHEMISTRY. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 2:21, s. 3085-90
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Journal article (peer-reviewed)abstract
- The formylated spirobyclic alcohol 8a was computer modeled to be a mimetic of paclitaxel. In this model, the formyl group was used as a truncated paclitaxel side chain in order to reduce the computational work. Compound 8c, carrying the paclitaxel side chain, was synthesized in six steps from optically active 1,3-diketone 12. Microtubule stabilization was not observed for 8c, indicating that the model needs to be adjusted.
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| 3. |
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| 4. |
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| 5. |
- Berg, Ulf, et al.
(author)
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Stereochemical variations on the colchicine motif. Peracid oxidation of thiocolchicone. Synthesis, conformation and inhibition of microtubule assembly
- 2004
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In: Organic and Biomolecular Chemistry. - : Royal Society of Chemistry (RSC). - 1477-0539 .- 1477-0520. ; 2:14, s. 2125-2130
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Journal article (peer-reviewed)abstract
- When 7-oxodesacetamidothiocolchicine ( 1) was treated with various peroxides in order to afford a Baeyer-Villiger rearrangement, a complex mixture of products was formed, which included the sulfoxide, ( 2) and sulfone, ( 3). When peracetic acid was used two additional products were formed; a C-ring lactone ( 4) and a ring-contracted allocolchicine derivative ( 5). The sulfoxide ( 2) was semi-preparatively resolved into enantiomers by chromatography on microcrystalline triacetylcellulose. Rotational barriers around the A - C pivot bond of 2, 4 and 5 were determined by dynamic H-1 NMR analysis. The compounds 2, 3, 4 and 7a exhibit moderate inhibition of tubulin polymerization, according to in vitro turbidity studies, whereas 5 was inactive.
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| 6. |
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| 7. |
- Doi, Hisashi, et al.
(author)
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Synthesis of 11C-labelled N,N’-diphenylurea and ethyl phenylcarbamate by rhodium-promoted carbonylation reaction via [11C]-isocyanatobenzene using phenyl azide and [11C]carbon monoxide
- 2004
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In: Organic and biomolecular chemistry. - 1477-0520 .- 1477-0539. ; 2:21, s. 3063-3066
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Journal article (peer-reviewed)abstract
- The reaction with phenyl azide and [11C]carbon monoxide to give N,N'-diphenyl[11C]urea and ethyl phenyl[11C]carbamate has been studied with the aim of development of a new methodology for carbonylation using [11C]carbon monoxide with high specific radioactivity. The synthesis of 11C-labelled N,N'-diphenylurea from phenyl azide and [11C]carbon monoxide, with 1,2-bis(diphenylphosphino)ethane-bound Rh(I) complex at 120 degrees C at a pressure of 35 MPa in the presence of aniline was accomplished in 82% trapping efficiency and 82% conversion yield. This approach was also useful for the synthesis of ethyl phenyl[11C]carbamate with lithium ethoxide as a nucleophilic reagent giving 90% trapping efficiency and 76% conversion yield. These reactions can be considered to proceed via a [11C]isocyanate or a [11C]isocyanate-coordinated Rh complex to give the corresponding 11C-products. This protocol provides the chemical basis for the synthesis of [11C]urea and [11C]carbamate derived from [11C]isocyanates.
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| 8. |
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| 9. |
- Emtenäs, Hans, et al.
(author)
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Stereoselective synthesis of optically active bicyclic -lactam carboxylic acids that target pilus biogenesis in pathogenic bacteria
- 2003
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In: Organic & Biomolecular Chemistry. - : Royal Society of Chemistry (RSC). - 1477-0520 .- 1477-0539. ; 1, s. 1308-14
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Journal article (peer-reviewed)abstract
- Optically active bicyclic -lactams were synthesized, starting from 2-H-2-thiazolines and Meldrum's acid derivatives. Several methods to accomplish an ester hydrolysis without damaging the -lactam framework were investigated. A rapid CsOH saponification of the -lactam methyl esters was developed and protonation of the Cs-carboxylates by Amberlite (IR-120 H+) afforded a series of bicyclic -lactam carboxylic acids. Moreover, a convenient method for the synthesis of 2-H-2-thiazolinecarboxylic acid methyl ester 2 was developed. Bicyclic -lactam carboxylic acids 7a–g and aldehydes 4a–d were screened for their affinity to the bacterial periplasmic chaperone PapD using a surface plasmon resonance technique. -Lactams substituted with large acyl substituents showed better binding to the chaperone than the native C-terminal peptide PapG 8, demonstrating that bicyclic -lactams constitute a new class of potential bacterial chaperone inhibitors.
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| 10. |
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