The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform
Hiromitsu Takayama - One of the best experts on this subject based on the ideXlab platform.
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asymmetric total synthesis of kopsiyunnanine k a monoterpenoid Indole Alkaloid with a rearranged skeleton
Organic Letters, 2016Co-Authors: Ryoko Tokuda, Mariko Kitajima, Noriyuki Kogure, Yoshiki Okamoto, Tetsuya Koyama, Hiromitsu TakayamaAbstract:A new monoterpenoid Indole Alkaloid, kopsiyunnanine K, was isolated from Kopsia arborea. Its intriguing rearranged structure and absolute configuration, which were inferred from spectral data and a possible biosynthetic pathway, were determined on the basis of a 13-step asymmetric total synthesis.
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asymmetric total synthesis of novel pentacyclic Indole Alkaloid kopsiyunnanine e isolated from kopsia arborea
Organic Letters, 2014Co-Authors: Mariko Kitajima, Noriyuki Kogure, Nobuaki Takahashi, Yosuke Murakami, Rongping Zhang, Hiromitsu TakayamaAbstract:A new pentacyclic Indole Alkaloid, kopsiyunnanine E, was isolated from Yunnan Kopsia arborea, and its structure, which was inferred from spectroscopic data, was established by a 16-step asymmetric total synthesis that proved that the natural Alkaloid was not enantiomerically pure.
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β-Carboline-type Indole Alkaloid glycosides from Ophiorrhiza trichocarpon
Tetrahedron, 2013Co-Authors: Mariko Kitajima, Noriyuki Kogure, Satoko Ohara, Dammrong Santiarworn, Hiromitsu TakayamaAbstract:Abstract Six new β-carboline-type Indole Alkaloid glycosides, ophiorrhisides A–F ( 1 – 6 ), were isolated from Ophiorrhiza trichocarpon (Rubiaceae) collected in Thailand. Ophiorrhisides A ( 1 ) and B ( 2 ) possess a lactam function in the C ring and a unique biose residue in the molecule. Ophiorrhiside F ( 6 ) has a highly oxidized C ring with a 1,2-dicarbonyl function at C-5 and C-6 positions as well as a double bond between C-3 and C-14.
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Asymmetric total synthesis of an iboga-type Indole Alkaloid, voacangalactone, newly isolated from Voacanga africana.
Organic letters, 2012Co-Authors: Masaya Harada, Mariko Kitajima, Masumi Iwai, Ken Nunettsu Asaba, Noriyuki Kogure, Hiromitsu TakayamaAbstract:A new hexacyclic iboga-type Indole Alkaloid, voacangalactone (1), was isolated from Voacanga africana , and its structure including the absolute configuration was established by asymmetric total synthesis involving such key steps as the asymmetric Diels-Alder reaction using an aminodiene and the construction of an isoquinuclidine ring and an Indole skeleton.
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determination of absolute configuration of trimeric Indole Alkaloid psychotrimine by first asymmetric total synthesis
Chemical Communications, 2010Co-Authors: Nobuaki Takahashi, Mariko Kitajima, Noriyuki Kogure, Yohei Matsuda, Takeshi Ito, Hiromitsu TakayamaAbstract:The first asymmetric total synthesis of psychotrimine, a trimeric Indole Alkaloid, was accomplished via an asymmetric Ireland–Claisen rearrangement to construct a chiral quaternary carbon center, thereby establishing the absolute configuration of psychotrimine.
Mariko Kitajima - One of the best experts on this subject based on the ideXlab platform.
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asymmetric total synthesis of kopsiyunnanine k a monoterpenoid Indole Alkaloid with a rearranged skeleton
Organic Letters, 2016Co-Authors: Ryoko Tokuda, Mariko Kitajima, Noriyuki Kogure, Yoshiki Okamoto, Tetsuya Koyama, Hiromitsu TakayamaAbstract:A new monoterpenoid Indole Alkaloid, kopsiyunnanine K, was isolated from Kopsia arborea. Its intriguing rearranged structure and absolute configuration, which were inferred from spectral data and a possible biosynthetic pathway, were determined on the basis of a 13-step asymmetric total synthesis.
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asymmetric total synthesis of novel pentacyclic Indole Alkaloid kopsiyunnanine e isolated from kopsia arborea
Organic Letters, 2014Co-Authors: Mariko Kitajima, Noriyuki Kogure, Nobuaki Takahashi, Yosuke Murakami, Rongping Zhang, Hiromitsu TakayamaAbstract:A new pentacyclic Indole Alkaloid, kopsiyunnanine E, was isolated from Yunnan Kopsia arborea, and its structure, which was inferred from spectroscopic data, was established by a 16-step asymmetric total synthesis that proved that the natural Alkaloid was not enantiomerically pure.
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β-Carboline-type Indole Alkaloid glycosides from Ophiorrhiza trichocarpon
Tetrahedron, 2013Co-Authors: Mariko Kitajima, Noriyuki Kogure, Satoko Ohara, Dammrong Santiarworn, Hiromitsu TakayamaAbstract:Abstract Six new β-carboline-type Indole Alkaloid glycosides, ophiorrhisides A–F ( 1 – 6 ), were isolated from Ophiorrhiza trichocarpon (Rubiaceae) collected in Thailand. Ophiorrhisides A ( 1 ) and B ( 2 ) possess a lactam function in the C ring and a unique biose residue in the molecule. Ophiorrhiside F ( 6 ) has a highly oxidized C ring with a 1,2-dicarbonyl function at C-5 and C-6 positions as well as a double bond between C-3 and C-14.
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Asymmetric total synthesis of an iboga-type Indole Alkaloid, voacangalactone, newly isolated from Voacanga africana.
Organic letters, 2012Co-Authors: Masaya Harada, Mariko Kitajima, Masumi Iwai, Ken Nunettsu Asaba, Noriyuki Kogure, Hiromitsu TakayamaAbstract:A new hexacyclic iboga-type Indole Alkaloid, voacangalactone (1), was isolated from Voacanga africana , and its structure including the absolute configuration was established by asymmetric total synthesis involving such key steps as the asymmetric Diels-Alder reaction using an aminodiene and the construction of an isoquinuclidine ring and an Indole skeleton.
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determination of absolute configuration of trimeric Indole Alkaloid psychotrimine by first asymmetric total synthesis
Chemical Communications, 2010Co-Authors: Nobuaki Takahashi, Mariko Kitajima, Noriyuki Kogure, Yohei Matsuda, Takeshi Ito, Hiromitsu TakayamaAbstract:The first asymmetric total synthesis of psychotrimine, a trimeric Indole Alkaloid, was accomplished via an asymmetric Ireland–Claisen rearrangement to construct a chiral quaternary carbon center, thereby establishing the absolute configuration of psychotrimine.
Noriyuki Kogure - One of the best experts on this subject based on the ideXlab platform.
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asymmetric total synthesis of kopsiyunnanine k a monoterpenoid Indole Alkaloid with a rearranged skeleton
Organic Letters, 2016Co-Authors: Ryoko Tokuda, Mariko Kitajima, Noriyuki Kogure, Yoshiki Okamoto, Tetsuya Koyama, Hiromitsu TakayamaAbstract:A new monoterpenoid Indole Alkaloid, kopsiyunnanine K, was isolated from Kopsia arborea. Its intriguing rearranged structure and absolute configuration, which were inferred from spectral data and a possible biosynthetic pathway, were determined on the basis of a 13-step asymmetric total synthesis.
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asymmetric total synthesis of novel pentacyclic Indole Alkaloid kopsiyunnanine e isolated from kopsia arborea
Organic Letters, 2014Co-Authors: Mariko Kitajima, Noriyuki Kogure, Nobuaki Takahashi, Yosuke Murakami, Rongping Zhang, Hiromitsu TakayamaAbstract:A new pentacyclic Indole Alkaloid, kopsiyunnanine E, was isolated from Yunnan Kopsia arborea, and its structure, which was inferred from spectroscopic data, was established by a 16-step asymmetric total synthesis that proved that the natural Alkaloid was not enantiomerically pure.
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β-Carboline-type Indole Alkaloid glycosides from Ophiorrhiza trichocarpon
Tetrahedron, 2013Co-Authors: Mariko Kitajima, Noriyuki Kogure, Satoko Ohara, Dammrong Santiarworn, Hiromitsu TakayamaAbstract:Abstract Six new β-carboline-type Indole Alkaloid glycosides, ophiorrhisides A–F ( 1 – 6 ), were isolated from Ophiorrhiza trichocarpon (Rubiaceae) collected in Thailand. Ophiorrhisides A ( 1 ) and B ( 2 ) possess a lactam function in the C ring and a unique biose residue in the molecule. Ophiorrhiside F ( 6 ) has a highly oxidized C ring with a 1,2-dicarbonyl function at C-5 and C-6 positions as well as a double bond between C-3 and C-14.
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Asymmetric total synthesis of an iboga-type Indole Alkaloid, voacangalactone, newly isolated from Voacanga africana.
Organic letters, 2012Co-Authors: Masaya Harada, Mariko Kitajima, Masumi Iwai, Ken Nunettsu Asaba, Noriyuki Kogure, Hiromitsu TakayamaAbstract:A new hexacyclic iboga-type Indole Alkaloid, voacangalactone (1), was isolated from Voacanga africana , and its structure including the absolute configuration was established by asymmetric total synthesis involving such key steps as the asymmetric Diels-Alder reaction using an aminodiene and the construction of an isoquinuclidine ring and an Indole skeleton.
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determination of absolute configuration of trimeric Indole Alkaloid psychotrimine by first asymmetric total synthesis
Chemical Communications, 2010Co-Authors: Nobuaki Takahashi, Mariko Kitajima, Noriyuki Kogure, Yohei Matsuda, Takeshi Ito, Hiromitsu TakayamaAbstract:The first asymmetric total synthesis of psychotrimine, a trimeric Indole Alkaloid, was accomplished via an asymmetric Ireland–Claisen rearrangement to construct a chiral quaternary carbon center, thereby establishing the absolute configuration of psychotrimine.
Yohei Matsuda - One of the best experts on this subject based on the ideXlab platform.
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determination of absolute configuration of trimeric Indole Alkaloid psychotrimine by first asymmetric total synthesis
Chemical Communications, 2010Co-Authors: Nobuaki Takahashi, Mariko Kitajima, Noriyuki Kogure, Yohei Matsuda, Takeshi Ito, Hiromitsu TakayamaAbstract:The first asymmetric total synthesis of psychotrimine, a trimeric Indole Alkaloid, was accomplished via an asymmetric Ireland–Claisen rearrangement to construct a chiral quaternary carbon center, thereby establishing the absolute configuration of psychotrimine.
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first total synthesis of trimeric Indole Alkaloid psychotrimine
Organic Letters, 2008Co-Authors: Yohei Matsuda, Mariko Kitajima, Hiromitsu TakayamaAbstract:The first total synthesis of (±)-psychotrimine, a novel trimeric Indole Alkaloid isolated from Psychotria rostrata, was achieved. In the total synthesis, the copper-mediated intramolecular and intermolecular aminations of halobenzenes, which respectively contributed to the construction of a pyrrolidinoindoline core and the installation of a third tryptamine unit, were used as key steps.
Nehir Unver - One of the best experts on this subject based on the ideXlab platform.
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GalanthIndole: a new Indole Alkaloid from Galanthus plicatus ssp. byzantinus.
Planta Medica, 2003Co-Authors: Nehir Unver, G. Irem Kaya, Christa Werner, Robert Verpoorte, Robert Verpoorte, Belkis GözlerAbstract:A new Indole Alkaloid, galanthIndole, was isolated from Galanthus plicatus ssp. byzantinus (Amaryllidaceae), a plant native to northwestern Turkey. Incorporating a non-fused Indole ring, galanthIndole may represent the prototype of a new subgroup of the Amaryllidaceae Alkaloids. Two other bases, (+)-11-hydroxyvittatine and hordenine, are also reported from the same plant.
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Geraniol 10-hydroxylase1, a cytochrome P450 enzyme involved in terpenoid Indole Alkaloid biosynthesis
FEBS letters, 2001Co-Authors: Graziella Collu, Nehir Unver, Robert Van Der Heijden, Robert Verpoorte, Anja M.g. Peltenburg-looman, Robert Verpoorte, Johan MemelinkAbstract:Geraniol 10-hydroxylase (G10H) is a cytochrome P450 monooxygenase involved in the biosynthesis of iridoid monoterpenoids and several classes of monoterpenoid Alkaloids found in a diverse range of plant species. Catharanthus roseus (Madagascar periwinkle) contains monoterpenoid Indole Alkaloids, several of which are pharmaceutically important. Vinblastine and vincristine, for example, find widespread use as anti-cancer drugs. G10H is thought to play a key regulatory role in terpenoid Indole Alkaloid biosynthesis. We purified G10H from C. roseus cells. Using degenerate PCR primers based on amino acid sequence information we cloned the corresponding cDNA. The encoded CYP76B6 protein has G10H activity when expressed in C. roseus and yeast cells. The stress hormone methyljasmonate strongly induced G10h gene expression coordinately with other terpenoid Indole Alkaloid biosynthesis genes in a C. roseus cell culture.