- Four new pentasaccharide resin glycosides from Ipomoea cairica with strong α-glucosidase inhibitory activity
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Six pentasaccharide resin glycosides from Ipomoea cairica, including four new acylated pentasaccharide resin glycosides, namely cairicoside I-IV (1-4) and the two known compounds cairicoside A (5) and cairicoside C (6), were isolated from the aerial parts of Ipomoea cairica. Their structures were established by a combination of spectroscopic, including two dimensional (2D) NMR and chemical methods. The core of the six compounds was simonic acid A, and they were esterfied the same sites, just differing in the substituent groups. The lactonization site of the aglycone was bonded to the second saccharide moiety at C-2 in 1-4, and at C-3 in 5-6. Compounds 1 and 5, 4 and 6 were two pairs of isomers. The absolute configuration of the aglycone in 1-6 which was (11S)-hydroxyhexadecanoic acid (jalapinolic acid) was established by Mosher's method. Compounds 1-4 have been evaluated for inhibitory activity against α-glucosidase, which all showed inhibitory activities.
- Pan, Jie-Tao,Yu, Bang-Wei,Yin, Yong-Qin,Li, Jie-Hong,Wang, Li,Guo, Li-Bing,Shen, Zhi-Bin
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- Three new resin glycosides compounds from Argyreia acuta and their α-glucosidase inhibitory activity
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Three new phenolic compounds, acutacoside C (1), acutacoside D (2) and acutacoside E (3) were isolated from the aerial part of Argyreia acuta. The oligosaccharide chain was composed of two glucoses and three rhamnoses, and the aglycone was (11S)-hydroxyhexadecanoic acid (jalapinolic acid). The core of the three compounds was operculinic acid B, which was rare in resin glycosides. Their structures were established by a combination of spectroscopic and chemical methods. Compounds 1-3 have been evaluated for inhibitory activity against α-glucosidase, which all showed weak inhibitory activities.
- Wang, Li,Yan, You-Shao,Cui, Hong-Hua,Yin, Yong-Qin,Pan, Jie-Tao,Yu, Bang-Wei
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- A cytotoxic and apoptosis-inducing sesquiterpenoid isolated from the aerial parts of Artemisia princeps PAMPANINI (Sajabalssuk)
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Repeated silica gel and octadecyl silica gel (ODS) column chromatography of the aerial parts of Artemisia princeps PAMPANINI (Sajabalssuk) led to the isolation of a new sesquiterpenoid, 3-((S)-2-methylbutyryloxy)-costu-1(10),4(5)- dien-12,6α-olide (2), along with two previously reported sesquiterpenoids: 8α-angeloyloxy-3β,4β-epoxy-6βH,7αH,8βH-guaia- 1(10),11(13)-dien-12,6α-olide (1, carlaolide B) and 3β,4β-epoxy- 8α-isobutyryloxy-6βH,7αH,8βH-guaia-1(10),11(13)-dien-12, 6α-olide (3, carlaolide A). The structure of compound 2 was elucidated by spectroscopic data analysis, including one dimensional (1D) and two dimensional (2D) nuclear magnetic resonance (NMR) experiments. Of the isolates, compound 2 exhibited potent cytotoxicity against human cervix adenocarcinoma cells and induced apoptosis.
- Bang, Myun-Ho,Han, Min-Woo,Song, Myoung-Chong,Cho, Jin-Gyeong,Chung, Hae-Gon,Jeong, Tae-Sook,Lee, Kyung-Tae,Choi, Myung-Sook,Kim, Se-Young,Baek, Nam-In
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- Heterogeneous catalytic hydrogenation of olefinic substrates by poly-NAP
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With our previously described poly-NAP, various olefinic substrates were reduced with selectivities comparable to those obtained by BINAP. For substrates which contained a methyl ester, the selectivities were higher than those observed for their carboxylic acid analogues. (C) 2000 Elsevier Science Ltd.
- Ter Halle, Rob,Schulz, Emmanuelle,Spagnol, Michel,Lemaire, Marc
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- Asymmetric Hydrogenation of α-Substituted Acrylic Acids Catalyzed by a Ruthenocenyl Phosphino-oxazoline-Ruthenium Complex
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Asymmetric hydrogenation of various α-substituted acrylic acids was carried out using RuPHOX-Ru as a chiral catalyst under 5 bar H2, affording the corresponding chiral α-substituted propanic acids in up to 99% yield and 99.9% ee. The reaction could be performed on a gram-scale with a relatively low catalyst loading (up to 5000 S/C), and the resulting product (97%, 99.3% ee) can be used as a key intermediate to construct bioactive chiral molecules. The asymmetric protocol was successfully applied to an asymmetric synthesis of dihydroartemisinic acid, a key intermediate required for the industrial synthesis of the antimalarial drug artemisinin.
- Li, Jing,Shen, Jiefeng,Xia, Chao,Wang, Yanzhao,Liu, Delong,Zhang, Wanbin
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supporting information
p. 2122 - 2125
(2016/06/01)
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- Enantioselective enolate protonation in sulfamichael addition to r-substituted n-acryloyloxazolidin-2-ones with bifunctional organocatalyst
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Organocatalytic conjugate addition of thiols to R-substituted N-acryloyloxazolidin-2-ones followed by asymmetric protonation has been studied in the presence of cinchona alkaloid derived thioureas. Both of the enantiomers are accessible with the same level of enantioselectivity using pseudoenantiomeric quinine/quinidine derived catalysts. The addition/protonation products have been converted to useful biologically active molecules. 2011 American Chemical Society.
- Rana, Nirmal K.,Singh, Vinod K.
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supporting information; experimental part
p. 6520 - 6523
(2012/02/01)
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- Pentasaccharide glycosides from the tubers of sweet potato (Ipomoea batatas)
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Sweet potato (Ipomoea batatas) has been used as food and herb in many countries. In this research on the active constituents of sweet potato, nine compounds were isolated and identified, including seven new resin glycosides, batatosides A-G (1-7), along with two known compounds, batatinoside I (8) and simonin IV (9). The structures of 1-9 have been established by a combination of spectroscopic and chemical methods. The major characteristics of the new compounds are the presence of three different substituents. The absolute configuration of aglycones was established as S by Mosher's method. Batatoside E (5) showed weak cytotoxic activity against Hep-2 cells.
- Yin, Yongqin,Li, Yi,Kong, Lingyi
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experimental part
p. 2363 - 2368
(2009/12/29)
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- Three new pentasaccharide resin glycosides from the roots of sweet potato (Ipomoea batatas)
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Three new pentasaccharide resin glycosides, batatosides III-V (1-3), were isolated from the roots of Sweet potato (Ipomoea batatas). Saponification of the crude resin glycoside mixture yielded substituents and simonic acid B. The structures of the isolate
- Yin, Yong-Qin,Huang, Xue-Feng,Kong, Ling-Yi,Niwa, Masatake
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experimental part
p. 1670 - 1674
(2009/12/04)
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- Hasubanan type alkaloids from Stephania longa
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Thirteen new hasubanan type alkaloids, stephalonines A-I (1-9), norprostephabyssine (15), isoprostephabyssine (16), isolonganone (18), and isostephaboline (21), as well as nine known ones, were isolated from the whole plants of Stephania longa, a well-known traditional Chinese medicine. Their structures were elucidated on the basis of spectroscopic data and chemical methods.
- Zhang, Hua,Yue, Jian-Min
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p. 1201 - 1207
(2008/09/17)
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- Pheromone synthesis, CXCVII. Synthesis of the enantiomers of 2-sec- butyl-4,5-dihydrothiazole and (1R,5S,7R)-3,4-dehydro-exo-brevicomin, pheromone components of the male mouse, Mus musculus
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Two components [2-sec-butyl-4,5-dihydrothiazole (1) and 3,4-dehydro-exo- brevicomin (2)] of a male-produced pheromone of the mouse Mus musculus have been synthesized in optically active forms. The enantiomers of 1 were obtained with an enantiomeric purity of ca. 92% ee and were found to be readily racemizable. Asymmetric dihydroxylation was employed as the key reaction (15→16) allowing the preparation of (1R,5S,7R)-2 with ca. 94% ee.
- Tashiro, Takuya,Mori, Kenji
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p. 2167 - 2173
(2007/10/03)
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- Resin glycosides. XV. Simonins I-V, ether-soluble resin glycosides (jalapins) from the roots of Ipomoea batatas (cv. Simon)
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Five new ether-soluble resin glycosides (jalapins), simonins I-V, have been isolated from the roots of Ipomoea batatas and characterized on the bases of chemical and spectral data. Simonin I is the first example of resin glycoside with aromatic acid (trans-cinnamic acid) as a component organic acid.
- Noda,Yoda,Kawasaki,Miyahara
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p. 3163 - 3168
(2007/10/02)
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