1. Induction of apoptosis in K562 cells by dicyclohexylammonium salt of hyperforin through a mitochondrial-related pathway
Jin-Yun Liu, Zhong Liu, Dong-Mei Wang, Man-Mei Li, Shao-Xiang Wang, Rui Wang, Jian-Ping Chen, Yi-Fei Wang, De-Po Yang Chem Biol Interact. 2011 Apr 25;190(2-3):91-101. doi: 10.1016/j.cbi.2011.02.026. Epub 2011 Mar 3.
Hyperforin is an abundant phloroglucinol-type constituent isolated from the extract of the flowering upper portion of the plant Hypericum perforatum L. The dicyclohexylammonium salt of hyperforin (DCHA-HF) has exhibited antitumor and antiangiogenic activities in various cancer cells. Here, the antitumor effects of DCHA-HF on the chronic myeloid leukemia K562 cell line were investigated for the first time. DCHA-HF exhibited dose- and time-dependent inhibitory activities against K562 cells, with IC(50) values of 8.6 and 3.2 μM for 48 h and 72 h of treatment, respectively, which was more effective than that of the hyperforin. In contrast, little cytotoxic activity was observed with DCHA-HF on HUVECs. DCHA-HF treatment resulted in induction of apoptosis as evidenced from DNA fragmentation, nuclear condensation and increase of early apoptotic cells by DAPI staining analysis, TUNEL assay and Annexin V-FITC/PI double-labeled staining analysis, respectively. Moreover, DCHA-HF elicited dissipation of mitochondrial transmembrane potential that commenced with the release of cytochrome c through down-regulation of expression of anti-apoptotic proteins and up-regulation of expression of pro-apoptotic proteins. DCHA-HF treatment induced activation of the caspase 3, 8, and 9 cascade and subsequent PARP cleavage, and DCHA-HF-induced apoptosis was significantly inhibited by caspase inhibitors. Treated cells were arrested at the G1 phase of the cell cycle and the expression of p53 and p27(Kip1), two key regulators related to cell cycle and apoptosis, was up-regulated. These results suggest that DCHA-HF inhibits K562 cell growth by inducing caspase-dependent apoptosis mediated by a mitochondrial pathway and arresting the cell cycle at the G1 phase. Therefore, DCHA-HF is a potential chemotherapeutic antitumor drug for chronic myeloid leukemia therapy.
2. Dicyclo-hexyl-ammonium 3,5-dinitro-benzoate
Sohail Saeed, Naghmana Rashid, Rizwan Hussain, Wing-Tak Wong Acta Crystallogr Sect E Struct Rep Online. 2012 Jul 1;68(Pt 7):o2168. doi: 10.1107/S1600536812027389. Epub 2012 Jun 23.
The asymmetric unit of the title salt, C(12)H(24)N(+)·C(7)H(3)N(2)O(6) (-), contains two cations and two anions. In the crystal, the cations and anions are connected by N-H⋯O hydrogen bonds, forming a 12-membered ring with an R(4) (4)(12) graph-set motif. The center of this 12-membered ring coincides with an inversion centre. π-π stacking is observed between parallel benzene rings [centroid-centriod distance = 3.771 (2) Å].
3. The formation of 2-hydroxypropylmercapturic acid from 1-halogenopropanes in the rat
E A Barnsley Biochem J. 1966 Aug;100(2):362-72. doi: 10.1042/bj1000362.
1. 2-Hydroxypropylmercapturic acid, i.e. N-acetyl-S-(2-hydroxypropyl)-l-cysteine, has been isolated, as the dicyclohexylammonium salt, from the urine of rats dosed with 1-bromopropane. 2. The formation of the same metabolite from 1-chloropropane, 1-iodopropane, 1,2-epoxypropane and 1-chloropropan-2-ol has been demonstrated by chromatographic examination of the urine excreted by rats after they had been dosed with these compounds. 3. (+)- and (-)-Dicyclohexylammonium 2-hydroxypropylmercapturate have been prepared by fractional crystallization of the mixture of isomers obtained by two methods: the reaction of 1,2-epoxypropane with l-cysteine followed by acetylation, and the reduction of 2-oxopropylmercapturic acid. 4. The following compounds have also been prepared: S-(3-hydroxypropyl)-l-cysteine, (+)- and (-)-S-(2-hydroxypropyl)-l-cysteine, dicyclohexylammonium 3-hydroxypropylmercapturate, (+)- and (-)-dicyclohexylammonium 2-hydroxy-1-methylethylmercapturate, and (+)- and (-)-dicyclohexylammonium 1-(ethoxycarbonyl)ethylmercapturate.
