97-67-6Relevant academic research and scientific papers
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.
METHODS OF PREPARATION OF MACROCYCLIC COMPOUNDS
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Page/Page column 24-25, (2009/10/18)
The instant invention describes methods for producing macrocyclic compounds having antiproliferation activity, and useful in methods of treating disorders such as cancer, tumors and cell proliferation related disorders.
Reverse reaction of malic enzyme for HCO3- fixation into pyruvic acid to synthesize L-malic acid with enzymatic coenzyme regeneration
Ohno, Yoko,Nakamori, Toshihiko,Zheng, Haitao,Suye, Shin-Ichiro
, p. 1278 - 1282 (2008/12/21)
Malic enzyme [L-malate: NAD(P)+ oxidoreductase (EC 1.1.1.39)] catalyzes the oxidative decarboxylation of L-malic acid to produce pyruvic acid using the oxidized form of NAD(P) (NAD(P)+). We used a reverse reaction of the malic enzyme of Pseudomonas diminuta IFO 13182 for HCO 3- fixation into pyruvic acid to produce L-malic acid with coenzyme (NADH) generation. Glucose-6-phosphate dehydrogenase (EC1.1.1.49) of Leuconostoc mesenteroides was suitable for coenzyme regeneration. Optimum conditions for the carboxylation of pyruvic acid were examined, including pyruvic acid, NAD+, and both malic enzyme and glucose-6-phosphate dehydrogenase concentrations. Under optimal conditions, the ratio of HCO 3- and pyruvic acid to malic acid was about 38% after 24 h of incubation at 30°C, and the concentration of the accumulated L-malic acid in the reaction mixture was 38mM. The malic enzyme reverse reaction was also carried out by the conjugated redox enzyme reaction with water-soluble polymer-bound NAD1.
Method for purifying succinic acid from fermentation broth
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Page/Page column 9, (2008/06/13)
Succinic acid is produced by bringing a succinic acid-containing liquid containing succinic acid and cation which is obtained by fermentation or an enzymatic method into contact with an H-type strongly acidic cation-exchange resin in an amount equivalent to or more than the amount of cation other than hydrogen ion contained in the succinic acid-containing liquid, and precipitating a crystal of succinic acid from the obtained ion-exchange-treated liquid to obtain purified succinic acid.
Purification and characterization of fumarase from Corynebacterium glutamicum
Genda, Tomoko,Watabe, Shoji,Ozaki, Hachiro
, p. 1102 - 1109 (2008/02/10)
Fumarase (EC 4.2.1.2) from Corynebacterium glutamicum (Brevibacterium flavum) ATCC 14067 was purified to homogeneity. Its amino-terminal sequence (residues 1 to 30) corresponded to the sequence (residues 6 to 35) of the deduced product of the fumarase gene of C. glutamicum (GenBank accession no. BAB98403). The molecular mass of the native enzyme was 200 kDa. The protein was a homotetramer, with a 50-kDa subunit molecular mass. The homotetrameric and stable properties indicated that the enzyme belongs to a family of Class II fumarase. Equilibrium constants (Keq) for the enzyme reaction were determined at pH 6.0, 7.0, and 8.0, resulting in Keq = 6.4, 6.1, and 4.6 respectively in phosphate buffer and in 16, 19, and 17 in non-phosphate buffers. Among the amino acids and nucleotides tested, ATP inhibited the enzyme competitively, or in mixed-type, depending on the buffer. Substrate analogs, meso-tartrate, D-tartrate, and pyromellitate, inhibited the enzyme competitively, and D-malate in mixed-type.
New results on the stereoselective alkylations of malic acid derivatives supported by molecular modeling
Sefkow, Michael,Koch, Andreas,Kleinpeter, Erich
, p. 4216 - 4229 (2007/10/03)
The stereoselectivity of the alkylation of dialkyl malates is dependent on steric hindrance of both ester alkyl groups. It was found that the two alkyl groups have opposite effects on diastereoselectivity. Increased steric hindrance at the C(1) carboxy group increases the anti-selectivity, whereas increased steric hindrance at the C(4) carboxy group decreases it. The results are explained by comparing the structures of the enolates, which were obtained by molecular modeling. Alkylation at C(4′) of dioxolanones, derived from benzyl-substituted malic acids, with an additional stereogenic center on the side chain is dependent on the stereogenic centers of the ring acetal and of the side chain. Alkylation at low temperatures occurs only with cis-dioxolanones having an (R)-configured side-chain stereogenic center. The corresponding trans-dioxolanone and the cis-dioxolanone with a (S)-configured side-chain stereogenic center were recovered unchanged. A rationale is presented with models of monolithiated dioxolanones obtained by ab initio calculations.
New phenolic constituents from the fruit juice of Phyllanthus emblica
Zhang,Tanaka,Yang,Kouno
, p. 537 - 540 (2007/10/03)
Six new phenolic constituents, L-malic acid 2-O- (1), mucic acid 2-O- (5), mucic acid 1,4-1actone 2-0- (6), 50- (8), 3-0- (10), and 3,5-di-0- (11) gallates, were isolated from the fruit juice of Phyllanthus emblica together with their methyl esters (2-4,
13C, 15N, and 18O equilibrium isotope effects and fractionation factors
Rishavy, Mark A.,Cleland
, p. 967 - 977 (2007/10/03)
A listing of 13C, 15N, and 18O equilibrium isotope effects and fractionation factors for atoms in specific positions is provided. Empirical factors that can be used to adjust these fractionation factors for more complex structures are presented and discussed. While much work needs to be done to determine equilibrium isotope effects for these heavy atoms, the values tabulated here should be useful to anyone working with isotope effects involving these atoms.
1,5-Asymmetric inductions in the reactions of 2-(2',3',4',6'-tetra-O-acetyl-β-D-glucopyranosyloxy)benzaldehyde with Danishefsky's diene
Cousins,Curtis,Ding,Stoodley
, p. 8689 - 8692 (2007/10/02)
The title compounds react to give mainly a 9:1 mixture of the aldols 14 and 15 in THF in the presence of BF3.OEt2, a 6:1 mixture of the cycloadducts 16 and 17 in THF in the presence of ZnCl2, and a 1:3 mixture of the cycloadducts 16 and 17 in toluene in the presence of Eu(fod)3.
