The Experts below are selected from a list of 1059 Experts worldwide ranked by ideXlab platform
Margaret A Brimble - One of the best experts on this subject based on the ideXlab platform.
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synthesis of the bis spiroacetal core of the Antimitotic Agent spirastrellolide b
Journal of Organic Chemistry, 2011Co-Authors: Jack L Y Chen, Margaret A BrimbleAbstract:The spirastrellolides are a family of potent Antimitotic Agents isolated from the marine sponge Spirastrella coccinea. Synthetic studies toward the DEF bis-spiroacetal core of spirastrellolide B are reported. A modular approach was pursued by the use of two dithiane disconnections to enable a highly convergent synthesis. The ease of lithiation and nucleophilicity of these 2-substituted-1,3-dithianes were investigated during the course of the synthesis, and the alkylations were found to proceed most efficiently at elevated temperatures. Formation of the [5,6,6]-bis-spiroacetal ring system was achieved via a double dithiane deprotection/spiroacetalization strategy.
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synthesis of the bis spiroacetal c25 c40 moiety of the Antimitotic Agent spirastrellolide b using a bis dithiane deprotection spiroacetalisation sequence
ChemInform, 2010Co-Authors: Jack L Y Chen, Margaret A BrimbleAbstract:The [5,6,6]-bis-spiroacetal moiety (II) of spirastrellolide B is prepared via a HgCl2-mediated double dithiane deprotection accompanied by a simultaneous bis-spiroacetalisation as a key step.
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synthesis of the bis spiroacetal c25 c40 moiety of the Antimitotic Agent spirastrellolide b using a bis dithiane deprotection spiroacetalisation sequence
Chemical Communications, 2010Co-Authors: Jack L Y Chen, Margaret A BrimbleAbstract:Use of a bis-dithiane deprotection–tandem bis-spiroacetalisation sequence was key to the successful synthesis of the [5,6,6]-bis-spiroacetal of the Antimitotic Agent spirastrellolide B, achieved in a highly convergent fashion involving successive dithiane alkylations.
Jack L Y Chen - One of the best experts on this subject based on the ideXlab platform.
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synthesis of the bis spiroacetal core of the Antimitotic Agent spirastrellolide b
Journal of Organic Chemistry, 2011Co-Authors: Jack L Y Chen, Margaret A BrimbleAbstract:The spirastrellolides are a family of potent Antimitotic Agents isolated from the marine sponge Spirastrella coccinea. Synthetic studies toward the DEF bis-spiroacetal core of spirastrellolide B are reported. A modular approach was pursued by the use of two dithiane disconnections to enable a highly convergent synthesis. The ease of lithiation and nucleophilicity of these 2-substituted-1,3-dithianes were investigated during the course of the synthesis, and the alkylations were found to proceed most efficiently at elevated temperatures. Formation of the [5,6,6]-bis-spiroacetal ring system was achieved via a double dithiane deprotection/spiroacetalization strategy.
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synthesis of the bis spiroacetal c25 c40 moiety of the Antimitotic Agent spirastrellolide b using a bis dithiane deprotection spiroacetalisation sequence
ChemInform, 2010Co-Authors: Jack L Y Chen, Margaret A BrimbleAbstract:The [5,6,6]-bis-spiroacetal moiety (II) of spirastrellolide B is prepared via a HgCl2-mediated double dithiane deprotection accompanied by a simultaneous bis-spiroacetalisation as a key step.
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synthesis of the bis spiroacetal c25 c40 moiety of the Antimitotic Agent spirastrellolide b using a bis dithiane deprotection spiroacetalisation sequence
Chemical Communications, 2010Co-Authors: Jack L Y Chen, Margaret A BrimbleAbstract:Use of a bis-dithiane deprotection–tandem bis-spiroacetalisation sequence was key to the successful synthesis of the [5,6,6]-bis-spiroacetal of the Antimitotic Agent spirastrellolide B, achieved in a highly convergent fashion involving successive dithiane alkylations.
Magdalena Litaay - One of the best experts on this subject based on the ideXlab platform.
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The Potency of ??-Sitosterol Isolated From Hydroid Aglaophenia cupressina Lamoureoux as Antimitotic Agent towards Seatowards Sea Urchin Tripneustes gratilla Linn.
2017Co-Authors: Eva Johannes, Magdalena LitaayAbstract:The potency of ??-Sitosterol isolated from hydroid Aglaophenia cupressina Lamoureoux as\ud Antimitotic Agent towards early cleavage of Sea Urchin Tripneustes gratilla Linn had been\ud conducted. The study aimed to determine ??-Sitosterol activity isolated compound from hydroid A. cupressina Lamoureoux as Antimitotic compound towards early cleavage of zygote of Sea Urchin T. gratilla Linn. Antimitotic treatments were ??-Sitosterol (concentration 1 ??g/ml, 10 ??g/ml and100??g/ml), positive control vincristine (concentration 0.01 ??g/ml, 0.1 ??g/ml, and 1 ??g/ml) and negative control. A protozoa-free seawater was used in this assay. The results revealed that ??-Sitosterol compound had the highest inhibition activity at concentration of 100 ??g/ml was 69.22 % with IC-50 on 0.95 ??g/ml which could develop as cancer chemotherapy compound. Keywords: Antimitotic, ??-Sitosterol, Hydroid Aglaophenia cupressina Lamoureoux, Tripneustes gratilla\ud Linn
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the potency of β sitosterol isolated from hydroid aglaophenia cupressina lamoureoux as Antimitotic Agent towards sea urchin tripneustes gratilla linn
International Journal of Engineering, 2017Co-Authors: Afriansyah Afriansyah, Eva Johannes, Sjafaraenan Sjafaraenan, Magdalena LitaayAbstract:The potency of β-Sitosterol isolated from hydroid Aglaophenia cupressina Lamoureoux as Antimitotic Agent towards early cleavage of Sea Urchin Tripneustes gratilla Linn had been conducted. The study aimed to determine β-Sitosterol activity isolated compound from hydroid A. cupressina Lamoureoux as Antimitotic compound towards early cleavage of zygote of Sea Urchin T. gratilla Linn. Antimitotic treatments were β-Sitosterol (concentration 1 µg/ml, 10 µg/ml and100 µg/ml), positive control vincristine (concentration 0.01 µg/ml, 0.1 µg/ml, and 1 µg/ml) and negative control. A protozoa-free seawater was used in this assay. The results revealed that β-Sitosterol compound had the highest inhibition activity at concentration of 100 μg/ml was 69.22 % with IC-50 on 0.95 µg/ml which could develop as cancer chemotherapy compound.
Ernest Hamel - One of the best experts on this subject based on the ideXlab platform.
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synthesis Antimitotic and antivascular activity of 1 3 4 5 trimethoxybenzoyl 3 arylamino 5 amino 1 2 4 triazoles
Journal of Medicinal Chemistry, 2014Co-Authors: Romeo Romagnoli, Maria Kimatrai Salvador, Andrea Brancale, Ernest Hamel, Pier Giovanni Baraldi, Filippo Prencipe, Valerio Bertolasi, Michela Cancellieri, Ignazio Castagliuolo, Francesca ConsolaroAbstract:A new class of compounds that incorporated the structural motif of the 1-(3′,4′,5′-trimethoxtbenzoyl)-3-arylamino-5-amino-1,2,4-triazole molecular skeleton was synthesized and evaluated for their antiproliferative activity in vitro, interactions with tubulin, and cell cycle effects. The most active Agent, 3c, was evaluated for antitumor activity in vivo. Structure–activity relationships were elucidated with various substituents on the phenyl ring of the anilino moiety at the C-3 position of the 1,2,4-triazole ring. The best results for inhibition of cancer cell growth were obtained with the p-Me, m,p-diMe, and p-Et phenyl derivatives 3c, 3e, and 3f, respectively, and overall, these compounds were more or less as active as CA-4. Their vascular disrupting activity was evaluated in HUVEC cells, with compound 3c showing activity comparable with that of CA-4. Compound 3c almost eliminated the growth of syngeneic hepatocellular carcinoma in Balb/c mice, suggesting that 3c could be a new Antimitotic Agent with c...
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synthesis and evaluation of 1 5 disubstituted tetrazoles as rigid analogues of combretastatin a 4 with potent antiproliferative and antitumor activity
Journal of Medicinal Chemistry, 2012Co-Authors: Romeo Romagnoli, Delia Preti, Maria Kimatrai Salvador, Andrea Brancale, Suzhan Zhang, Xianhua Fu, Mojgan Aghazadeh Tabrizi, Pier Giovanni Baraldi, Ernest HamelAbstract:Tubulin, the major structural component of microtubules, is a target for the development of anticancer Agents. Two series of 1,5-diaryl substituted 1,2,3,4-tetrazoles were concisely synthesized, using a palladium-catalyzed cross-coupling reaction, and identified as potent antiproliferative Agents and novel tubulin polymerization inhibitors that act at the colchicine site. SAR analysis indicated that compounds with a 4-ethoxyphenyl group at the N-1 or C-5 position of the 1,2,3,4-tetrazole ring exhibited maximal activity. Several of these compounds also had potent activity in inhibiting the growth of multidrug resistant cells overexpressing P-glycoprotein. Active compounds induced apoptosis through the mitochondrial pathway with activation of caspase-9 and caspase-3. Furthermore, compound 4l significantly reduced in vivo the growth of the HT-29 xenograft in a nude mouse model, suggesting that 4l is a promising new Antimitotic Agent with clinical potential.
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synthesis x ray crystal structure and tubulin binding properties of a benzofuran analogue of the potent cytotoxic Agent combretastatin a4
Australian Journal of Chemistry, 1999Co-Authors: Martin G Banwell, Bernard L Flynn, Anthony C Willis, Ernest HamelAbstract:The benzofuran (4), a ring-fused analogue of the potent Antimitotic Agent combretastatin A4 (1), has been prepared by a convergent route involving 5-endo-dig iodocyclization of o-hydroxytolan (5) as the key step. Compound (4), which has been characterized crystallographically as well as spectroscopically, is inactive as a tubulin-binding Agent.
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Curacin D, aN Antimitotic Agent from the marine Cyanobacterium Lyngbya majuscula
Phytochemistry, 1998Co-Authors: Brian L. Marquez, Ernest Hamel, Pascal Verdier-pinard, William H. GerwickAbstract:Curacin D is a novel brine shrimp toxic metabolite isolated from a Virgin Islands collection of the marine cyanobacterium Lyngbya majuscula. Structure elucidation of curacin D was accomplished through multidimensional NMR, GC/MS, and comparisons with curacin A. Curacin D provides new insights into structure-activity relationships in this natural product class as well as some aspects of the likely biosynthetic pathway of the curacins.
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structure of curacin a a novel Antimitotic antiproliferative and brine shrimp toxic natural product from the marine cyanobacterium lyngbya majuscula
Journal of Organic Chemistry, 1994Co-Authors: William H. Gerwick, Ernest Hamel, Dale G. Nagle, Philip Proteau, Andrei V Blokhin, Doris L SlateAbstract:Bioassay-guided fractionation of the organic extract of a Curacao collection of Lyngbya majuscula led to the isolation of a new lipid, curacin A, with exceptional brine shrimp toxic and antiproliferative activities. Its unique thiazoline-containing structure has been deduced from spectroscopic information. Pure curacin A is an Antimitotic Agent (IC 50 values in three cell lines ranging from 7 to 200 nM) that inhibits microtubule assembly and the binding of colchicine to tubulin
William H. Gerwick - One of the best experts on this subject based on the ideXlab platform.
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Curacin D, aN Antimitotic Agent from the marine Cyanobacterium Lyngbya majuscula
Phytochemistry, 1998Co-Authors: Brian L. Marquez, Ernest Hamel, Pascal Verdier-pinard, William H. GerwickAbstract:Curacin D is a novel brine shrimp toxic metabolite isolated from a Virgin Islands collection of the marine cyanobacterium Lyngbya majuscula. Structure elucidation of curacin D was accomplished through multidimensional NMR, GC/MS, and comparisons with curacin A. Curacin D provides new insights into structure-activity relationships in this natural product class as well as some aspects of the likely biosynthetic pathway of the curacins.
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absolute configuration of curacin a a novel Antimitotic Agent from the tropical marine cyanobacterium lyngbya majuscula
Tetrahedron Letters, 1995Co-Authors: Dale G. Nagle, William H. Gerwick, R S Geralds, Hyedong Yoo, Taeseong Kim, Mitch Nambu, James D WhiteAbstract:Curacin A is a structurally novel Antimitotic Agent isolated from the Caribbean cyanobacterium Lyngbya majuscula. Its planar structure has been previously determined from a spectroscopic investigation. Here, we define the complete relative and absolute configuration of curacin A by comparison of products obtained from chemical degradation of the natural product with the same substances prepared by synthesis. Curacin A is shown to have 2R, 13R, 19R, 21S absolute configuration.
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structure of curacin a a novel Antimitotic antiproliferative and brine shrimp toxic natural product from the marine cyanobacterium lyngbya majuscula
Journal of Organic Chemistry, 1994Co-Authors: William H. Gerwick, Ernest Hamel, Dale G. Nagle, Philip Proteau, Andrei V Blokhin, Doris L SlateAbstract:Bioassay-guided fractionation of the organic extract of a Curacao collection of Lyngbya majuscula led to the isolation of a new lipid, curacin A, with exceptional brine shrimp toxic and antiproliferative activities. Its unique thiazoline-containing structure has been deduced from spectroscopic information. Pure curacin A is an Antimitotic Agent (IC 50 values in three cell lines ranging from 7 to 200 nM) that inhibits microtubule assembly and the binding of colchicine to tubulin