0000000000114695
AUTHOR
Siavosh Mahboobi
showing 12 related works from this author
Synthesis of the Racemates of the b-Carboline Alkaloid Chrysotricine and its Diastereomer
2000
The racemates of the rubiacea alkaloid Chrysotricine (1) and its diastereomer are synthesized from the isomeric mixture of linalyl oxides 3 and tryptamine in six steps, followed by separation of the diastereomers.
Synthesis of pyrrolo[3′,4′:2,3]azepino[4,5,6-cd]indole-8,10-diones
2000
3-Amino-4-(3-indolyl)pyrrolin-2,5-diones are condensed with various aldehydes and ketones to the cor responding imines. Under Pictet-Spengler conditions, the latter do not cyclize to pyrrolo-β-carbolines, but readily yield pyrrolo[3′,4′:2,3]azepino[4,5,6-cd]indole-8,10-diones.
Synthesis of Naturally Occurring Pyrazine and Imidazole Alkaloids from Botryllus LeachiRID=?a?ID=?a? Dedicated to Prof. G . Märkl on the occasion of …
2004
The synthesis of the naturally occurring and biologically active alkaloids 1 and 2, first isolated from the red ascidian Botryllus leachi by Duran et al. [1], is described and the structure proposed for Botryllazine B (1) is confirmed. The analytical data for 2-(p-hydroxybenzoyl)-4-(p-hydroxyphenyl)imidazole (2) are discussed and compared with the literature. With special emphasis of 1H NMR data the tautomerism of aroylimidazolemethanones is described.
Bis(1H-indol-2-yl)methanones are effective inhibitors of FLT3-ITD tyrosine kinase and partially overcome resistance to PKC412A in vitro.
2009
Inhibition of the mutated fms-like tyrosine kinase 3 (FLT3) receptor tyrosine kinase is a promising therapeutic strategy in acute myeloid leukaemia (AML). However, development of resistance to FLT3 tyrosine kinase inhibitors (TKI), such as PKC412A, has been described recently. This observation may have an increasing impact on the duration of response and relapse rates in upcoming clinical trials employing FLT3-TKI. Herein we investigated two representatives of a novel class of FLT3-TKI: Bis(1H-indol-2-yl)methanones. Both compounds effectively induced apoptosis in FLT3-internal tandem duplicate (ITD)-transfected murine myeloid cells and in primary FLT3-ITD positive blasts. Combination of bot…
Synthesis of bis(indolylmaleimide) macrocycles
2000
The synthesis of a novel class of macrocyclic bis(indolylmaleimides) is reported. The key step involves the intermolecular connection of 2,2′-bridged indoles with 3,4-dibromo-2,5-dihydro-1H-2,5-pyrroledione (dibromomaleimide) derivatives. The bis(indolylmaleimides) afforded by this method were further processed by intramolecular nucleophilic substitution of the remaining bromo substituents forming flexible N-substituted macrocycles (9a-9j, 10a-10e) and, by connecting both maleimides, semi rigid macrocycles (7a-7xx).
Synthesis of Pyrrolidin-2-ones and of Staurosporine Aglycon (K-252c) by Intermolecular Michael Reaction
1999
Indolo[2,3-a]pyrrolo[3,4-c]carbazoles were isolated from nature, e.g., from low plants, especially fungi, as structurally rare natural substances. Responsible for naming and also the most important representative of this type is staurosporine (1), isolated from Streptomyces staurosporeus, and its aglycon (2), also known as staurosporinone or K-252c. 3,4-Disubstituted pyrrolidin-2-ones, a group of compounds with many interesting biological properties are related to staurosporinone. The most important property is the inhibition of protein kinase C (PKC), so that this antiproliferative agent can interfere with the cell cycle. The synthetic strategy, developed by us, allows the synthesis of pyr…
X-ray Crystal Structure of Woodinine and Conformational Analysis by Semiempirical and 1H-NMR Methods
1997
The mol. structure of (-)-woodinine (I), a carboline-based alkaloid with antibacterial and antimycobacterial activities, was investigated by X-ray crystallog., NMR, and semiempirical quantum chem. methods. The X-ray crystal structure of I showed the indole ring in the expected planar conformation, the pyrrolidine ring in an envelope conformation, and a weak intramol. hydrogen bond between the pyrrolidine nitrogen and the proton of the indole nitrogen. NMR expts. indicated that this hydrogen bond is not present in soln. and that further differences exist between the crystal and the soln. structures of I. By semiempirical quantum chem. methods, different local energy min. conformations of I, …
HDAC1 and HDAC2 integrate the expression of p53 mutants in pancreatic cancer.
2015
Mutation of p53 is a frequent genetic lesion in pancreatic cancer being an unmet clinical challenge. Mutants of p53 have lost the tumour-suppressive functions of wild type p53. In addition, p53 mutants exert tumour-promoting functions, qualifying them as important therapeutic targets. Here, we show that the class I histone deacetylases HDAC1 and HDAC2 contribute to maintain the expression of p53 mutants in human and genetically defined murine pancreatic cancer cells. Our data reveal that the inhibition of these HDACs with small molecule HDAC inhibitors (HDACi), as well as the specific genetic elimination of HDAC1 and HDAC2, reduce the expression of mutant p53 mRNA and protein levels. We fur…
Concepts to Target MYC in Pancreatic Cancer.
2016
Abstract Current data suggest that MYC is an important signaling hub and driver in pancreatic ductal adenocarcinoma (PDAC), a tumor entity with a strikingly poor prognosis. No targeted therapies with a meaningful clinical impact were successfully developed against PDAC so far. This points to the need to establish novel concepts targeting the relevant drivers of PDAC, like KRAS or MYC. Here, we discuss recent developments of direct or indirect MYC inhibitors and their potential mode of action in PDAC. Mol Cancer Ther; 15(8); 1792–8. ©2016 AACR.
Class I histone deacetylases regulate p53/NF-κB crosstalk in cancer cells
2016
The transcription factors NF-κB and p53 as well as their crosstalk determine the fate of tumor cells upon therapeutic interventions. Replicative stress and cytokines promote signaling cascades that lead to the co-regulation of p53 and NF-κB. Consequently, nuclear p53/NF-κB signaling complexes activate NF-κB-dependent survival genes. The 18 histone deacetylases (HDACs) are epigenetic modulators that fall into four classes (I-IV). Inhibitors of histone deacetylases (HDACi) become increasingly appreciated as anti-cancer agents. Based on their effects on p53 and NF-κB, we addressed whether clinically relevant HDACi affect the NF-κB/p53 crosstalk. The chemotherapeutics hydroxyurea, etoposide, an…
ChemInform Abstract: Synthesis of Pyrrolidin-2-ones and of Staurosporine Aglycon (K-252c) by Intermolecular Michael Reaction.
2010
Indolo[2,3-a]pyrrolo[3,4-c]carbazoles were isolated from nature, e.g., from low plants, especially fungi, as structurally rare natural substances. Responsible for naming and also the most important representative of this type is staurosporine (1), isolated from Streptomyces staurosporeus, and its aglycon (2), also known as staurosporinone or K-252c. 3,4-Disubstituted pyrrolidin-2-ones, a group of compounds with many interesting biological properties are related to staurosporinone. The most important property is the inhibition of protein kinase C (PKC), so that this antiproliferative agent can interfere with the cell cycle. The synthetic strategy, developed by us, allows the synthesis of pyr…
ChemInform Abstract: Synthesis of Bis(indolylmaleimide) Macrocycles
2000
The synthesis of a novel class of macrocyclic bis(indolylmaleimides) is reported. The key step involves the intermolecular connection of 2,2′-bridged indoles with 3,4-dibromo-2,5-dihydro-1H-2,5-pyrroledione (dibromomaleimide) derivatives. The bis(indolylmaleimides) afforded by this method were further processed by intramolecular nucleophilic substitution of the remaining bromo substituents forming flexible N-substituted macrocycles (9a-9j, 10a-10e) and, by connecting both maleimides, semi rigid macrocycles (7a-7xx).