- Trans -Hydroboration-oxidation products in ?5-steroids via a hydroboration- retro -hydroboration mechanism
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Herein, we report for the first time a trans-hydroboration-oxidation product isolated and characterized under traditional hydroboration-oxidation conditions using cholesterol and diosgenin as substrates. These substrates are excellent starting materials because of the rigidity and different structural environments around the double bond. Further investigations based on experimental evidence, in conjunction with theoretical studies, indicate that the formation of this trans-species occurs via a retro-hydroboration of the major product to generate the corresponding ?6-structure and the subsequent hydroboration by the ?-face. Besides, the corresponding Markovnikov type products have been isolated in synthetically useful yields. The behavior of the reaction under a range of temperatures is also investigated.
- Bernès, Sylvain,Duarte, Fernanda,Dzib, Eugenia,Fernández-Herrera, María A.,García-Méndez, Jair,Hilario-Martínez, J. Ciciolil,Kürti, László,Merino, Gabriel,Mu?oz-Hernández, Miguel ángel,Murillo, Fernando,Sandoval-Ramírez, Jesús
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p. 12764 - 12768
(2020/12/30)
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- Novel steroid -based amphiphiles and uses thereof
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The present invention relates to a newly developed steroid-based amphiphilic compound, a preparation method thereof and a method for extracting, solubilizing, stabilizing, crystallizing or analyzing membrane proteins using the same. In addition, the compound, compared to the conventional compounds, can efficiently extract membrane proteins having various structures and properties from cell membranes and store the same in an aqueous solution for a long time, and thus can be used for functional analysis and structural analysis. Membrane protein structure and function analysis thereof is one of the areas of greatest interest in current biology and chemistry by being closely related to drug development.COPYRIGHT KIPO 2020
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Paragraph 0199-0202
(2020/05/23)
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- TIMOSAPONIN COMPOUNDS
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Provided herein are timosaponin compounds of Frmula I, II, IIΙ, I', II' and IIΙ', pharmaceutical compositions comprising the coumpounds, and processes of preparation thereof. Also provided are uses of said timosaponin compounds for preparing medicament for the treatment of diseases associated with beta-amyloid in hosts or subjects in need thereof.
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Paragraph 00259
(2013/10/22)
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- The convergent synthesis of novel cytotoxic certonardosterol D2 from diosgenin
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Certonardosterol D2, a polyhydroxysterol isolated from starfish Certonardoa semiregularis with exceptionally potent antitumor activity, was stereoselectively synthesized from natural rich diosgenin via the protocol of Julia olefination and Evan
- Jiang, Biao,Shi, He-ping,Tian, Wei-sheng,Zhou, Wei-shan
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p. 469 - 476
(2008/03/28)
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- New chlorogenin hexasaccharide isolated from Agave fourcroydes with cytotoxic and cell cycle inhibitory activities
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A new chlorogenin hexasaccharide (1) was isolated from leaves of Agave fourcroydes (Agavaceae). The structure of the new saponin was elucidated as chlorogenin 3-O-[α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl- (1→3)-{β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl- (1→2)}-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside] (1) by spectroscopic analysis and the result of acidic hydrolysis. The new saponin (1) as well as known hexasaccharides (3 and 5) isolated here showed cytotoxicity against HeLa cells, and 1 exhibited a cell cycle inhibitory effect at the G2/M stage at the concentration of 7.5 and 10μg/mL.
- Ohtsuki, Takashi,Koyano, Takashi,Kowithayakorn, Thaworn,Sakai, Shinobu,Kawahara, Nobuo,Goda, Yukihiro,Yamaguchi, Naoto,Ishibashi, Masami
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p. 3841 - 3845
(2007/10/03)
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- Spirostanic analogues of teasterone. Synthesis, characterisation and biological activity of laxogenin, (23S)-hydroxylaxogenin and 23-ketolaxogenin (23-oxolaxogenin)
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The synthesis and characterization of the naturally occurring steroid sapogenin laxogenin and its derivatives 23-ketolaxogenin and (23S)-hydroxylaxogenin were described. Compounds reported have shown plant-growth-stimulating activity in tests and field trials. The effect consisted of an increase of the length of the treated hypocotyls compared with that of the non-treated plants. Results showed that when the same solutions were applied to the seeds of orange tree, a strong promotion of the germination was observed.
- Iglesias-Arteaga, Martin A.,Perez Gil, Roxana,Perez Martinez, Carlos S.,Coll Manchado, Francisco
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p. 261 - 266
(2007/10/03)
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- Steroidal glycosides from the aerial parts of Polianthes tuberosa
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A chemical investigation of the aerial parts of Polianthes tuberosa resulted in the isolation of a new bisdesmosidic cholestane glycoside (1) and three new spirostanol saponins (2-4), along with a known cholestane glycoside. The structures of new glycosides were determined bY spectroscopic analysis, including 2D NMR spectroscopic data, and the results of hydrolytic cleavage. The isolated compounds were evaluated for their cytotoxic activity on HL-60 human promyelocytic leukemia cells.
- Mimaki, Yoshihiro,Yokosuka, Akihito,Sashida, Yutaka
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p. 1519 - 1523
(2007/10/03)
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- Synthesis of (22R, 25R)-3β,26-dihydroxy-5α-furostan-6-one
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The synthesis of a plant growth promoter furostanol which bears the characteristic functionality of teasterone on rings A and B is described.
- Iglesias Arteaga, Martin A.,Perez Gil, Roxana,Leliebre Lara, Vivian,Perez Martinez, Carlos S.,Coll Machado, Francisco,Rosado Perez, Aristide,Pozo Rios, Luis
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p. 1381 - 1386
(2007/10/03)
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- Steroidal saponins from the bulbs of Camassia cusickii.
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Six new steroidal saponins have been isolated from the fresh bulbs of Camassia cusickii. Their structures were determined by spectroscopic analysis and some chemical transformations to be (25R)-5 alpha-spirostan-3 beta,6 alpha-diol (chlorogenin) 6-O-beta-D-glucopyranoside, chlorogenin 6-O-beta-D-glucopyranosyl-(1----2)-beta-D-glucopyranoside, chlorogenin 6-O-beta-D-glucopyranosyl-(1----3)-beta-D-glucopyranoside, chlorogenin 6-O-beta-D-glucopyranosyl-(1----2)-O-[beta-D-glucopyranosyl-(1----3)]-beta- D-glucopyranoside, (25R)-6 alpha-hydroxy-5 alpha-spirostan-3-one 6-O-beta-D-glucopyranosyl- (1----3)-beta-D-glucopyranoside and (25R)-3,3-dimethoxy-5 alpha-spirostan-6 alpha-ol 6-O-beta-D-glucopyranosyl-(1----3)-beta-D-glucopyranoside. The saponins isolated were shown to contribute to the bitter taste of the bulbs.
- Mimaki,Sashida,Kawashima
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p. 3721 - 3727
(2007/10/02)
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- A SPIROSTANOL GLYCOSIDE FROM AGAVE CANTALA
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A new steroidal saponin has been isolated from the ethanolic extract of the roots of Agave cantala and shown to be 3-O--6-O--(25R)-5α-22α-O-spirostan-3β,6α-diol.Key Word Index - Agave cantala; Agavaceae; saponins; spirostanol glycoside; 3-O--6-O--(25R)-5α-22α-O-spirostan-3β,6α-diol.
- Sharma, S. C.,Sati, O. P.
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p. 1820 - 1821
(2007/10/02)
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