636-61-3Relevant articles and documents
Racemic Structure and Optical Resolution by Preferential Crystallization of (+/-)-Organic Ammonium Hydrogen Malates
Shiraiwa, Tadashi,Sado, Yujin,Inoue, Mitsuo,Sakamoto, Keiji,Miyazaki, Hideya,Kurokawa, Hidemoto
, p. 899 - 904 (1988)
Gibbs energies of formation of racemate, binary melting point diagrams, and ternary solubility diagrams indicate that (+/-)-propylammonium ((+/-)-PA salt) and (+/-)-1,1,3,3-tetramethylbutylammonium ((+/-)-TMB salt) hydrogen malates are conglomerates at room temperature, whereas (+/-)-TMB salt forms a racemic compound at its melting point.Free energies of critical nucleation in supersaturated solutions were examined to resolve (+/-)-PA and -TMB salts efficiently by preferential crystallization.Successive preferential crystallization of (+/-)-PA salt in methanol at 10 deg C and that of (+/-)-TMB salt in water give (+)- and (-)-PA and -TMB salts with about 90percent optical purity.Optically pure (+)- and (-)-malic acids are obtained from purified (-)- and (+)-salts.
Sesquiterpene dimers esterified with diverse small organic acids from the seeds of Sarcandra glabra
Wang, Peng,Luo, Jun,Zhang, Yang-Mei,Kong, Ling-Yi
, p. 5362 - 5370 (2015/07/15)
11 new sesquiterpene dimers, sarglabolides A-K (1-11), and five known ones were isolated from the seeds of Sarcandra glabra. Their structures were elucidated by spectroscopic data analysis and chemical evidence. Sarglabolide A (1) was verified to exclusively possess a seventeen-membered macrocyclic ester ring formed by the scaffold of the sesquiterpene dimer and small organic acids, different from the eighteen-membered rings of the other reported analogues. The chiral small organic acid moieties were assigned to l-malic acid, d-malic acid, and d-tartaric acid based on the combination of spectroscopy, chemical derivatization and HPLC analysis. Dimers 1, 12 and 13 can significantly inhibit NO production in LPS-induced macrophages with IC50 values at 3.04, 4.65 and 2.33 μmol/L, respectively.
An approach to the chemotaxonomic differentiation of two European Dog's mercury species: Mercurialis annua L. and M. perennis L.
Lorenz, Peter,Duckstein, Sarina,Conrad, Juergen,Knoedler, Matthias,Meyer, Ulrich,Stintzing, Florian C.
experimental part, p. 282 - 297 (2012/05/04)
Mercurialis annua and M. perennis are medicinal plants used in complementary medicine. In the present work, analytical methods to allow a chemotaxonomic differentiation of M. annua and M. perennis by means of chemical marker compounds were established. In addition to previously published compounds, the exclusive presence of pyridine-3-carbonitrile and nicotinamide in CH2Cl2 extracts obtained from the herbal parts of M. annua was demonstrated by GC/MS. Notably, pyridine-3-carbonitrile was identified for the first time as a natural product. Further chromatographic separation of the CH2Cl2 extracts via polyamide yielded a MeOH fraction exhibiting a broad spectrum of side-chain saturated n-alkylresorcinols. While the n-alkylresorcinol pattern was similar for both plant species, some specific differences were observed for particular n-alkylresorcinol homologs. Finally, the investigation of H2O extracts by LC/MS/MS revealed the presence of depside constituents. Whereas, in M. perennis, a mixture of mercurialis acid (=(2R)-[(E)-caffeoyl]-2-oxoglutarate) and phaselic acid (=(E)-caffeoyl-2-malate) could be detected, in M. annua solely phaselic acid was found. By comparison with synthesized enantiomerically pure (2R)- and (2S)-phaselic acids, the configuration of the depside could be determined as (2S) in M. annua and as (2R) in M. perennis.
Process for preparing R-(-) -carnitine from S-(-)-chlorosuccinic acid or from a derivative thereof
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Page column 9, (2008/06/13)
An inner salt of L-carnitine is prepared by reduction, with a suitable reducing agent, of a compound of formula (I): where X1and X2, which may be the same or different, are hydroxy, C1-C4alkoxy, phenoxy, halogen, or X1and X2, when taken together are an oxygen atom and the resulting compound is a derivative of succinic anhydride; Y is halogen, the mesyloxy or the tosyloxy group: and subsequent treatment with water, then with a base and then with trimethylamine.