The RC tumor, originally a renal adenocarcinoma very sensitive to different classes of chemotherapeutic agents, maintained in CDF 1 mice, was examined for its ability to metastasize. When inoculated into the foot (with 10(7) tumor cells), bulky metastases developed in the popliteal and para-aortic lymph nodes, in a constant and reproducible pattern, producing a massive microscopic invasion of the liver, the lungs and the spleen. The antigenicity tests demonstrated a low immunogenicity of the tumor. Chemotherapy assays showed that adriamycin and vincristine were effective against metastatic dissemination when administered early after tumor cell inoculation and principally when combined with excision of the tumor-bearing leg. The RC model appears to be suitable for the study of lymph node metastasis and could be used in chemotherapy trials of new drugs potentially effective against metastases of the lymphatic system.

Herein, we describe the structure-activity relationship study of a new 3-aryl-8H-thieno[2,3-b]pyrrolizin-8-one series of antitubulin agents. The pharmacological results from the National Cancer Institute in vitro human disease oriented tumor cell line screening allowed us to identify compound 1d (NSC 676693) as a very efficient antitumoral drug in all cancer cell lines tested. This prompted us to define the structural requirements essential for this antiproliferative activity. Among all analogues synthesized in this study, compound 1o was the most promising, being 10-fold more potent than compound 1d. Its activity over a panel of nine tumoral cell lines was in the nanomolar range for all of the histological types tested, and surprisingly, the resistant KB-A1 cell line was also sensitive to this compound. Moreover, a flow cytometric study showed that L1210 cells treated by the most potent compounds were arrested in the G(2)/M phases of the cell cycle with a significant percentage of cells having reinitiated a cycle of DNA synthesis without cell division. This interesting pharmacological profile, resulting from inhibition of tubulin polymerization, encouraged us to perform preliminary in vivo studies that led to a new prodrug chemical approach.

Ecomustine, or CY233 (NSC-609224), is a new water-soluble nitrosoureido sugar derived from acosamine. A high-performance liquid chromatographic assay (HPLC) developed to quantify the unchanged drug in aqueous solutions and biological specimens enabled us to study the chemical stability as a function of pH, light, and temperature. In buffered aqueous solutions, the kinetics of degradation of CY233 is a first-order process. The log k-pH profile demonstrated hydroxide ion-catalyzed solvolysis. The drug is most stable at pH 4, more stable than some other nitrosoureas in 5% glucose (t1/2, 62-67 h) and in 0.9% isotonic saline (t1/2, 25-37 h) solutions. Based on these findings, blood samples should be collected in cold tubes (4 degrees C) containing citrate buffer (pH 4) and all manipulations should be protected from heat and light.

A new type of ether of dihydroartemisinin containing cyano and aryl groups was prepared and tested for cytotoxicity to A549, P388, L1210 and HT29 cells using the MTT assay. 12k and 12l were the most cytotoxic compounds. 13 lacking the peroxy group showed a 1000-fold less potency than 12l. Similarly, the inactive compound 14 indicated that the position of cyano groups was also important. Flow cytometry data showed that the compounds caused an accumulation of P388 cells in the G(1)-phase of the cell cycle.

Condensation of N-methyl-1,3-dihydroxyacridone with 3-methyl-2-butenal led selectively to norisoacronycine, which upon methylation gave isoacronycine. Functionalization of the 1,2 double bond of isoacronycine led to derivatives with reduced cytotoxicity compared with the corresponding ones deriving from acronycine. Two very interesting exceptions were 1-hydroxy-1,2-dihydroisoacronycine (14) and its acetate (16), which showed strong induction of apoptosis.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Heading Abstract Background. The new olivacine derivative S 16020-2 (NSC-659687) has entered clinical trials on the basis of a marked antitumor activity in experimental models. Amongst the analogues which were synthesized to improve both therapeutic index and antitumor activity, the most active ones were those esterified on the 9-OH group such as S 30972-1, the glutaric acid monoester derivative. Purpose. To compare the pharmacological profile of S 30972-1 and S 16020-2 in vitro and in vivo and to investigate whether S 30972-1 could act as a prodrug of S 16020-2. Methods. The two compounds were compared in vitro in terms of their activity in inhibiting cellular proliferation and perturbing the cell cycle and in vivo in terms of their antitumor activity in murine transplantable tumors and human orthotopic models. The plasma concentrations of S 16020-2 and S 30972-1 were determined in mice, in a comparative pharmacokinetic study after i.v. administration, using an HPLC assay. Results. Although tumor cell proliferation and accumulation of cells in the G 2 phase of the cell cycle were similarly affected by the two compounds after a continuous exposure (IC 50 values of 30–50 n M ), S 30972-1 was about tenfold less potent than S 16020-2 after short exposures. In vivo, S 30972-1 induced more long-term survivors than S 16020-2 among mice with Lewis lung carcinoma and sensitive or multidrug resistant P388 leukemias. The growth of Colon 38 carcinoma was slightly more inhibited by S 30972-1 than S 16020-2. In the more relevant human orthotopic models, using the optimal doses of each drug, 160 mg/kg S 30972-1 was significantly more active than 80 mg/kg S 16020-2 in the NCI-H460 lung carcinoma. The two compounds were significantly active in A549 lung carcinoma, moderately active in the NIH:OVCAR-3 ovary carcinoma and inactive in the NCI-H125 lung and DU145 prostate carcinomas. Pharmacokinetic study demonstrated that S 30972-1 is a prodrug of S 16020-2: the conversion was rapid and complete within 1 h of the administration of S 30972-1. Conclusions. The in vivo profile of these two compounds appeared very similar, although S 30972-1 exhibited globally a wider therapeutic index. The rapid conversion of S 30972-1 to S 16020-2 shows that S 30972-1 acts mainly as a prodrug of S 16020-2. This should be taken into account before considering S 30972-1 as a valuable back-up of S 16020-2.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

As part of a research program directed towards the design and synthesis of pyranoxanthones structurally related to acronycine, we present here the synthesis and cytotoxic activity of the pyranoxanthones 3 and 4 (X = H, Br; R = H, OMe; R' = H, Ac). Some of these compounds inhibit L1210 cell proliferation.

Condensation of 3-hydroxy-2-naphthalenecarboxylic acid with phloroglucinol afforded 1,3-dihydroxy-12H-benzo[b]xanthen-12-one. Construction of an additional dimethylpyran ring onto this skeleton, by alkylation with 3-chloro-3-methyl-1-butyne followed by Claisen rearrangement, gave access to a series of benzo[b]pyrano[2,3-i]xanthen-6-ones and benzo[b]pyrano[3,2-h]xanthen-7-ones related to psorospermine and benzo[b]acronycine. In contrast with what is observed in the pyridoacridone and benzopyridoacridone series, the linear benzo[b]-pyrano[2,3-i]xanthen-6-one derivatives were more potent than their angular benzo[b]pyrano[3,2-h]xanthen-7-one isomers. cis-3,4-Diacetoxy-5-methoxy-2,2-dimethyl-3,4-dihydro-2H,6H-benzo[b]pyrano[2,3-i]xanthen-6-one, the most active among the new compounds, was more potent than acronycine in inhibiting the proliferation of L1210 murine leukemia cells.