- A new megastigmane sulphoglycoside and polyphenolic constituents from pericarps of Garcinia mangostana
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A megastigmane sulphoglycoside together with three phenolic compounds were isolated from the water-soluble fraction of the pericarps of Garcinia mangostana. The structure of the new compound was determined as 4-O-sulpho-β-d-glucopyranosyl abscisate (1) by spectroscopic data. Proanthocyanidin A2 (2) showed potent α-glucosidase inhibitory and DPPH scavenging activities with IC50values of 3.46 and 11.6 μM, respectively.
- Tran, Thu Huong,Le Huyen, Tram,Tran, Thi Minh,Nguyen, Tuan Anh,Pham, Thanh Binh,Nguyen Tien, Dat
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p. 1598 - 1604
(2016/07/06)
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- Synthesis and biological activity of abscisic acid esters
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Abstract 16 ABA esters including 11 new compounds were prepared by two different esterification routes. All the structures of ABA esters were confirmed by 1H NMR, 13C NMR and HRMS. Their biological activity and hydrolysis stability were investigated. Fortunately, there were 15 and 9 compounds which displayed much better or nearly the same inhibition activity for rice seedling growth and Arabidopsis thaliana seed germination compared to ABA, respectively. Especially, compounds 2d and 2g showed better biological activities than ABA in the three tests. Moreover, we found that chemical hydrolysis ability of the esters in vitro had little relationship to their biological activity.
- Wan, Chuan,Zhang, Yuanzhi,Yang, Dongyan,Han, Xiaoqiang,Li, Xiuyun,Li, Hong,Xiao, Yumei,Qin, Zhaohai
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p. 267 - 272
(2015/06/22)
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- Concise enantioselective synthesis of abscisic acid and a new analogue
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Short and high-yielding syntheses of enantiomerically pure (S)-(+) and (R)-(-)-abscisic acid are described. The syntheses proceed through key intermediates that preferentially recrystallise as single diastereoisomers for each enantiomer. This route allows the preparation of either enantiomer of abscisic acid in ca. 30% overall yield, and as demonstrated, gives access to an enantiomerically pure abscisic acid analogue. The Royal Society of Chemistry 2006.
- Smith, Timothy R.,Clark, Andrew J.,Clarkson, Guy J.,Taylor, Paul C.,Marsh, Andrew
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p. 4186 - 4192
(2008/09/19)
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- Resolution of (+)-abscisic acid using an Arabidopsis glycosyltransferase
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Abscisic acid (ABA) can exist as two enantiomers, with (+)-ABA as the naturally occurring form. Typically, both enantiomers occur in chemical preparations and both can be modified in the plant to their respective glucose esters. To identify glycosyltransferases capable of discriminating between the different forms of ABA, the Family 1 enzymes of Arabidopsis thaliana were screened for activity towards (±)-ABA. Eight enzymes were found to recognise the plant hormone, with one UGT71B6 showing enantioselective glucosylation towards (+)-ABA. UGT71B6 was used in a whole-cell biocatalysis system as a means of separating (+)- and (-)-ABA, thereby offering an alternative to chemical synthesis for the production of pure (+)-ABA.
- Lim, Eng-Kiat,Doucet, Charlotte J.,Hou, Bingkai,Jackson, Rosamond G.,Abrams, Suzanne R.,Bowles, Dianna J.
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p. 143 - 147
(2007/10/03)
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- Crop-selective herbicide
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An agricultural chemical composition which comprises a first component having herbicidal activity selected from the group consisting of glyphosate and the like and a second component selected from the group consisting of phosphorus acid derivatives and the like and may further comprise a third component selected from maleic hydrazide and the like; and use of it as a plant growth retardant and crop selective herbicide.
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- Synthesis, Biological Activity, and Metabolism of 8′,8′,8′-Trideuteroabscisic Acid
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An 8′,8′,8′-trideuterated analog of abscisic acid (ABA) was diastereoselectively synthesized as a new analog of ABA that is resistant to 8′-hydroxylation, the first metabolic reaction of ABA, owing to the primary kinetic isotope effect. (+)-8′,8′,8′-Trideutero-ABA showed long-term activity in the rice elongation assay. The rate of metabolism of this analog in rice cell suspension culture was about two fold slower than that of (+)-ABA. The concentration of 8′,8′-dideuterophaseic acid produced was about 1/3 that of phaseic acid converted from (+)-ABA. This result indicated that the long-lasting activity of the (+)-trideutero-ABA in the rice assay was the result of the delayed 8′-hydroxylation as expected.
- Todoroki, Yasushi,Nakano, Sei-Ichi,Hirai, Nobuhiro,Mitsui, Toshiaki,Ohigashi, Hajime
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p. 1872 - 1876
(2007/10/03)
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- Facile Preparation of Chiral Abscisic Acid
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The asymmetric epoxidation of (+/-)-methyl (2Z,4E)-1',4'-dihydroxy-α-ionylideneacetates is described for the preparation of chiral abscisic acid.A conventional Sharpless kinetic resolution of (+/-)-1',4'-cis-dihydroxyacetate with diethyl L-tartrate and then two simple steps of conversion gave (S)-abscisic acid, which was also obtained by combination of (+/-)-1',4'-trans-dihydroxyacetate with diethyl D-tartrate.Finally, (S)-abscisic acid was obtained in a 25percent overall yield from the racemic mixture.
- Yamamoto, Hiroshi,Oritani, Takayuki
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p. 992 - 994
(2007/10/02)
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- Convenient Syntheses of Optically Active Abscisic Acid and Xanthoxin
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The Reformatzky reaction of 3-(bromomethyl)crotonate with an optically active epoxycyclohexane aldehyde derivative (3), followed by dehydration, gave the chiral dienoic acid (6) stereospecifically.The product was derived to optically active abscisic acid (1) and xanthoxin (2) successfully.
- Sakai, Kunikazu,Takahashi, Kyoko,Nukano, Tomoko
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p. 8229 - 8239
(2007/10/02)
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- Syntheses of Chiral 4'-Hydroxy and 1',4'-Dihydroxy-γ-ionylideneacetic Acids, Fungal Biosynthetic Intermediates of Abscisic Acid
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Both chiral 4'-hydroxy and 1',4'-dihydroxy-γ-ionylideneacetic acids (3, 4 and 5), biosynthetic intermediates of abscisic acid produced by Cercospora cruenta, were synthesized from a chiral starting material, (R)- or (S)-4-hydroxy-2,2-dimethyl-1-cyclohexanone (7). -Sigmatropic rearrangement of (S)-1-chloromethyl-3,3-dimethyl-5-tetrahydropyranyl(THP)oxy-1-cyclohexene (8), followed by the Reformatsky reaction with 4-bromo-3-methyl-2-butenoate (10) gave (1'R,4'S)-4.The diastereomeric isomer, (1'R,4'R)-3, was synthesized in the same manner.The reaction of (S)-2,2-dimethyl-5-methylene-4-THPoxy-1-cyclohexanone (14) with a Grignard reagent prepared from (Z)-3-methyl-2-penten-4-ynyl THP ether (15) and subsequent conversion of the side chain gave (1'S,4'S)-5.These synthetic compounds confirmed the stereochemistry of natural 3, 4 and 5.
- Yamamoto, Hiroshi,Oritani, Takayuki,Yamashita, Kyohei
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p. 1923 - 1929
(2007/10/02)
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- Enantioselective Reduction of Racemic Abscisic Acid by Aspergillus niger Cultures
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Biotransformation of racemic abscisic acid 1a with cultures of Aspergillus niger gives rise to the enantioselective reduction of the (S)-enantiomer to afford the corresponding (1'S,2'R)-(-)-2',3'-dihydro-ABA acid 2a in high enantiomeric excess (e.e.).The structure, stereochemistry, and preferred conformation of compound 2a have been elucidated on the basis of NMR evidence.
- Arnone, Alberto,Cardillo, Rosanna,Nasini, Gianluca,Pava, Orso Vajna de
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p. 3061 - 3063
(2007/10/02)
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- RATIO OF (S)- TO (R)-ABSCISIC ACID FROM PLANT CELL CULTURES SUPPLIED WITH RACEMIC ABA
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Determinations of the ratios of (S)- to (R)-abscisic acid have been made by an NMR method employing γ-cyclodextrin as a chiral complexing agent with the sodium salt of abscisic acid.In cultures of bromegrass cells that have been fed synthetic racemic abscisic acid the natural isomer is depleted from the medium much more rapidly than the unnatural form.The NMR method is shown to be applicable to biologically active compounds related to abscisic acid.Key Word Index - Bromus inermis; Gramineae; bromegrass; NMR; optical isomer; cyclodextrin; abscisic acid; abscisic acid analogues.
- Abrams, Suzanne R.,Reaney, Martin J. T.,Abrams, Garth D.,Mazurek, Ted,Shaw, Angela C.,Gusta, Lawrence V.
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p. 2885 - 2890
(2007/10/02)
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- Synthesis of (+)-Abscisic acid
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Starting from (4S)-4-hydroxy-2,6,6-trimethylcyclohex-2-enone (2), a short synthesis of the natural (+)-abscisic acid ((+)-1) has been accomplished.
- Soukup, Milan,Lukac, Teodor,Lohri, Bruno,Widmer, Erich
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p. 361 - 364
(2007/10/02)
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- THE STABILITY OF THE 1',4'-DIOLS OF ABSCISIC ACID
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The 1',4'-cis and 1',4'-trans-diols of abscisic acid (ABA) are unstable in acidic conditions: they interconvert and oxidize to ABA.When the diols were held in acidic (pH 4) H2O the oxygen atoms of both the 1'- and 4'-hydroxyl groups exchanged with the medium with retention and inversion of configuration.Thus the (+)--trans-diol was epimerized to the (+)--cis-diol and to the (-)--cis-diol.Similarly, the cis and trans-diol lost 18O during epimerization.The trans-diol was the more stable by about 30percent and was also less prone to oxidation to ABA.Significant epimerization of the cis-diol occurred below pH 6 while an equivalent reaction of the trans-diol occurred below pH 5.Key Word Index - 1',4'-trans-diol of ABA; 1',4'-cis-diol of ABA; 1',4'-dihydroabscisic acid; epimerization; abscisic acid.
- Vaughan, G. T.,Milborrow, B. V.
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p. 339 - 344
(2007/10/02)
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- Glycinoeclepins, Natural Hatching Stimuli for the Soybean Cyst Nematode, Heterodera Glycines. I. Isolation
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Hatching stimuli, designated as glycinoeclepins, for the soybean cyst nematode (Heterodera glycines) have been isolated by repeated chromatography of the aqueous extracts of dried roots of kidney bean (Phaseolus vulgaris), one of the host plants of the nematode.One of these compounds, glycinoeclepin A, stimulates the hatching and emergence of larvae in vitro in highly diluted aqueous solutions.
- Masamune, Tadashi,Anetai, Masaki,Fukuzawa, Akio,Tagasuki, Mitsuo,Matsue, Hideki,et al.
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p. 981 - 1000
(2007/10/02)
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