RESUMEN
Extensive phytochemical investigation on the methanol extract of the inflorescences, twigs, and leaves of Brucea javanica led to the isolation and identification of 27 triterpenoids, including 21 previously undescribed ones, named brujavanoids A-U (1-21). Their structures were determined based on comprehensive spectroscopic analysis and single-crystal X-ray diffraction. Of these compounds, brujavanoid A (1) represents the first apotirucallane-type triterpenoid with a novel 19(10 â 9)abeo motif, and brujavanoids B and C (2-3) are the first apotirucallane-type triterpenoids with a rarely occurring 14-hydorxy-15,16-epoxy fragment. All the isolates were evaluated for their anti-inflammatory effect in an LPS-activated RAW264.7 cells model. Furthermore, the most active one, brujavanoid E (5), can suppress the transcriptional expression of typical pro-inflammatory mediators and inhibit the nuclear translocation of NF-κB p65 in the LPS- activated RAW264.7 cells.
Asunto(s)
Brucea , Triterpenos , Antiinflamatorios/farmacología , Brucea/química , Brucea javanica , Lipopolisacáridos/farmacología , Triterpenos/química , Triterpenos/farmacologíaRESUMEN
In the title compound, C(23)H(22)N(2)O(6), the crystal packing is stabilized by inter-molecular N-Hâ¯O hydrogen bonds, which link the mol-ecules into chains running parallel to the c axis. Inter-molecular C-Hâ¯O hydrogen bonds are also present in the structure.
RESUMEN
There are two mol-ecules in the asymmetric unit of the title compound, C(17)H(20)O(4)S(2). There are slight differences in the twist of the two rings relative to the S-C-S chain [dihedral angles of 48.41â (18) and 87.58â (16)° in the first mol-ecule and 45.98â (18) and 87.02â (18)° in the second] and the difference in the C-S-C-S torsion angles [176.68â (17) and -77.6â (2)° for the two independent mol-ecules].
RESUMEN
Some approaches for improving recombinant phenylalanine ammonia lyase (PAL) stability in Escherichia coli during the enzymatic methods of l-phenylalanine (l-Phe) production were developed following preliminary studies by means of statistical-based experiment designs (response surface method). The traditional non-statistical technology was used to screen four critical factors for PAL stability during the bioconversion process, viz., glycerin, sucrose, 1,4-dithiothreitol (DTT), and MgSO(4). The central composite design (CCD) was applied to optimize the combined effect of critical factors for recombinant PAL stability and understand the relationship between the factors and PAL stability. The optimum values for testing variables were 13.04 mM glycerin, 1.87 mM sucrose, 4.09 mM DTT, and 69 mM Mg(2+). A second-order model equation was suggested and then validated experimentally. The model adequacy was very satisfactory because the coefficient of determination was 0.88. The maximum PAL activity was retained as 67.73 units/g after three successive cycles of bioconversion. In comparison to initial PAL activity, the loss of PAL activity was only 22%. PAL activity was enhanced about 23% in comparison to the control (without any stabilizer additives). PAL stability was significantly improved during successive bioconversion. The results obtained here verified the effectiveness of the applied methodology and may be helpful for l-Phe production on an industrial scale.