• YAKHAK HOEJI
• /
• v.32 no.4
• /
• pp.245-250
• /
• 1988

Naphthoquinone derivatives have been found to be anticoagulant. In this report, several new 2-chloro-3-(N-arylamino)-naphthoquinone derivatives were synthesized in oder to develope mild anticoagulant. 2, 3-dichloro-1, 4-naphthoquinone was reacted with p-aminobenzoic acid, m-aminobenzoic acid, toluidine, m-nitroaniline, sulfanilamide, sulfathiazole, sulfaguanidine, phenetidine, 2-aminopyrimidine and 3-amino-5-methylisoxazole in EtOH or AcOH afford 2-chloro-3-(p-carboxy anilino)-naphthoquinone (1), 2-chloro-3-(m-carboxyanilino)-naphthoquinone (2),2-chloro-3-(toluidino)-naphthoquinone (3),2-chloro-3-(m-nitroanilino)-naphthoquinone (4), 2-chloro-3-(4-sulfanilanilino)-naphthoquinone (5), 2-chloro-3-(4-sulfathiazolino)-naphthoquinone (6),2-chloro-3-(4-sulfaguanidino)-naphthoquinone (7),2-chlro-3-(phenetidino)-naphthoquinone (8), 2-chloro-3-(pyrimidine-2-amino)-naphthoquinone (9) and 2-chloro-3-(5-methylisoxazole-3-amino)-naphthoquinone (10) in good yield.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.5
• /
• pp.1833-1837
• /
• 2015

An aristolactam-type alkaloid, isolated from Orophea enterocarpa, is enterocarpam-III (10-amino-2,3,4,6-tetramethoxyphenanthrene-1-carboxylic acid lactam). It is cytotoxic to various human and murine cancer cell lines; however, the molecular mechanisms remain unclear. The aims of this study were to investigate cytotoxic effects on and mechanism (s) of human cancer cell death in human hepatocellular carcinoma HepG2 and human invasive breast cancer MDA-MB-231 cells compared to normal murine fibroblast NIH3T3 cells. Cell viability was determined by MTT assay to determine $IC_{10}$, $IC_{20}$ and $IC_{50}$ levels, reactive oxygen species (ROS) production with 2',7'-dichlorohydrofluorescein diacetate and the caspase-3, -8 and -9 activities using specific chromogenic (p-nitroaniline) tetrapeptide substrates, viz., DEVD-NA, IETD-NA and LEHD-NA and employing a microplate reader. Mitochondrial transmembrane potential (MTP) was measured by staining with 3, 3'-dihexyloxacarbocyanine iodide ($DiOC_6$) and using flow cytometry. The compound was cytotoxic to HepG2 and MDA-MB-231 cells with the $IC_{50}$ levels of $26.0{\pm}4.45$ and $51.3{\pm}2.05{\mu}M$, respectively. For murine normal fibroblast NIH3T3 cells, the $IC_{50}$ concentration was $81.3{\pm}10.1{\mu}M$. ROS production was reduced in a dose-response manner in HepG2 cells. The caspase-9 and -3 activities increased in a concentration-dependent manner, whereas caspase-8 activity did not alter, indicating the intrinsic pathway activation. Enterocarpam-III decreased the mitochondrial transmembrane potential (MTP) dose-dependently in HepG2 cells, suggesting that the compound induced HepG2 cell apoptosis via the mitochondrial pathway. In conclusion, enterocarpam-III inhibited HepG2 and MDA-MB-231 cell proliferation and induced human HepG2 cells to undergo apoptosis via the intrinsic (mitochondrial) pathway and induction of caspase-9 activity.

• Archives of Pharmacal Research
• /
• v.25 no.4
• /
• pp.505-510
• /
• 2002

An improved kinetic assay for prekallikrein activator (PKA), a potential vasodilator, has been developed to be used as an indicator for quality control during production of human albumin preparations. It consists of two reaction stages. In the first stage, PKA and prekallikrein are incubated at $37^{\circ}C$ for 45 min to allow the transformation into kallikrein. Kallikrein, a serine protease, catalyzes the splitting of p-nitroaniline (pNA) from its substrate H-D-Pro-Phe-Arg-pNA(S-2302). The rate at which pNA is released was measured spectrophotometrically at 405 nm. Prekallikrein, a substrate of PKA was purified by DEAE ion-exchange chromatography and the major potential variations in the assay were optimized; pH 8.0 and 150 mM sodium chloride were chosen to give a proper ionic strength. Reaction times in the range of 10 to 360 min provided linear dose-response curves. The concentration of prekallikrein was adjusted to fall between 1:1 and 1:3 dilutions to generate a linear standard calibration curve. Under the optimized conditions, reproducibility was checked. In a precision test, the coefficient of variation (CV) stayed within ${\pm}4%$ and the dose-response curve showed a good correlation (${r^2}=0.999$). An accuracy test with an international standard of PKA afforded a mean recovery of 97.5%.