1 Chloroquine was given in 300 mg single doses as an i.v. infusion, an oral solution and as tablets at intervals of at least 56 days to 11 healthy volunteers. Concentrations of chloroquine and its metabolite desethylchloroquine were measured in plasma, erythrocytes and urine using h.p.l.c.

No abstract

Three new compounds, 5 alpha-lanosta-7,9(11),24-triene-3beta-hydroxy-26-al (1), 5 alpha-lanosta-7,9(11),24-triene-15 alpha-26-dihydroxy-3-one (2), and 8 alpha,9 alpha-epoxy-4,4,14 alpha-trimethyl-3,7,11,15,20-pentaoxo-5 alpha-pregnane (3), were isolated from Ganoderma concinna along with 12 known compounds. The structures of compounds 1 and 2 were determined on the basis of MS and NMR studies. The structure of 3 was determined by MS, NMR, and single-crystal X-ray diffraction. Compounds 1, 2, and 3 induce apoptosis in human promyelocytic leukemia HL-60 cells, as indicated by examining the morphological features of cells and detection of DNA fragmentation by gel electrophoresis.

In this paper we report the isolation and structural elucidation of a new flavonoid (1) and three known compounds, 6,8-di-C-methylkaempferol 3-methyl ether (2), oleanolic acid, and 2 alpha,3 beta-dihydroxyurs-12-en-28-oic acid, from aerial parts of Eucalyptus occidentalis collected in Algeria. Flavonoids 1 and 2 were used to study their biological activities on the human promyelocytic leukemia cell line, HL-60. Our data show that these compounds induce morphological changes and internucleosomal DNA fragmentation characteristic of apoptotic cell death, which is mediated by caspase-8/caspase-3 activation and cytochrome c release.

From the stem bark of Dracaena draco, three new compounds, namely, draconins A-C (1-3), were isolated, along with 17 known compounds. The structures of the new compounds isolated were elucidated on the basis of spectroscopic data interpretation. Several of the isolated compounds showed potent cytotoxic activities measured on the human leukemia cell line HL-60 (IC(50)'s from 2.0 to 9.7 microM at 72 h). The mechanism by which compounds 1 and 2 display their cytostatic properties is through induction of cell death by apoptosis, as evaluated by fluorescence microscopy and DNA fragmentation.

We have synthesized and evaluated a series of hybrids of polypyrrole minor groove binders structurally related to the natural antitumor agent distamycin A, and alpha-methylene-gamma-butyrolactones with methyl, phenyl, and 4-substituted phenyl groups at the lactone C(gamma) position, denoted 5-17, for in vitro cytotoxic activity against a variety of cancer cell lines. The apoptotic and cytotoxic activities against several tumor cell lines are reported and discussed in terms of their structural differences in relation to both the number of N-methylpyrrole rings and the type of the alkylating unit tethered to the oligopeptidic frame. It may be noted that in general, and especially for 11, 12, and 17, the cytotoxicity of the hybrids was much greater than that of the alpha-methylene-gamma-butyrolactone units 24a-g alone. Using the human leukemia cell line HL-60, we have tested the effects of a selected series of compounds on programmed cell death (apoptosis). The results clearly indicate that 11, 12, and 17, but not 9, are able to induce apoptosis as demonstrated from (i) identification of nuclear changes associated with apoptosis using fluorescence microscopy and (ii) by DNA laddering on agarose gel electrophoresis. Compound 12 was the most potent, especially after a short incubation period. It induced extensive hydrolysis of poly ADP-ribose polymerase (PARP), considered to be a hallmark of apoptosis, which plays a critical role in chromatin architecture and DNA metabolism.

Ins(1,4,5)P3 metabolism was examined in Saccharomyces cerevisiae extracts. S. cerevisiae contains readily detectable Ins(1,4,5)P3 kinase activity that is predominantly soluble, but phosphomonoesterase activity acting on Ins(1,4,5)P3 was not detected in either soluble or particulate preparations from this organism. We have purified the kinase activity approximately 685-fold in a rapid four-step process, and obtained a stable preparation. The enzyme has an apparent native molecular mass of approximately 40 kDa, and displays Michaelis-Menten kinetics with respect to its two substrates, ATP and Ins(1,4,5)P3. The Km for ATP was 2.1 mM, and that for Ins(1,4,5)P3 was 7.1 microM. The enzyme appeared to be the first step in the conversion of Ins(1,4,5)P3 into an InsP5, and the partially purified preparation contained another activity that converted the InsP4 product into an InsP5. The InsP4 product of the partially purified kinase was not metabolized by human erythrocyte ghosts and co-chromatographed with an Ins(3,4,5,6)P4 [L-Ins(1,4,5,6)P4] standard, identifying it as D-Ins(1,4,5,6)P4. The yeast enzyme is thus an Ins(1,4,5)P3 6-kinase. This activity may be an important step in the production of inositol polyphosphates such as InsP5 and InsP6 in S. cerevisiae.

In [3H]serine-labelled granulosa cells treatment with TNF alpha (10 ng/ml) resulted in a transient decrease in cellular [3H]sphingomyelin and generation of [3H]ceramide that remained elevated 60 min later. In cells labelled with [methyl-14C]choline, TNF alpha induced a similar reduction in [14C]sphingomyelin content that was accompanied by a sustained elevation in [14C]phosphorylcholine levels. In FSH-primed cells, TNF alpha inhibited P450-AROM activity in a dose-dependent manner, an effect that was also observed in cells treated with bacterial sphingomyelinase (SMase 0.003-0.3 U/ml) or increasing concentrations (0.1-10 microM) of N-acetylsphingosine (C2-cer) a membrane-permeable analogue of ceramide. These results support the notion that sphingomyelin degradation to a bioeffector molecule ceramide, may be an early event involved in TNF alpha-induced signal transduction in granulosa cells.