Evidence for 4-hydroxyalkenals in rat renal cortex peroxidized by N2-methyl-9-hydroxyellipticinium acetate or Celiptium

The antitumor drug celiptium is an ellipticine derivative whose nephrotoxic pathogenesis implicates a lipid peroxidation process. It has been shown that hydrophobic lipid deposits overload the proximal tubular cells. Histochemistry with Holczinger's technique has demonstrated that these deposits are free fatty acids. In this study, the fatty acid analysis of phospholipids and neutral lipids was performed in rat renal cortex 4 and 8 days following a single i.v. dose of 20 mg/kg celiptium and showed: (1) a loss of polyunsaturated fatty acids within total phospholipids and a loss of phosphatidylethanolamine with a preferential decrease of arachidonic (20:4) and docosahexaenoic (22:6) acids; (2) an increase of free fatty acid levels with an increase in oleic (18:1) and linoleic (18:2) acids; (3) an increase of thiobarbituric acid-reactive substances or aldehydes. The analysis of these aldehydes showed significant amounts of 4-hydroxyalkenals, mainly the presence of 4-hydroxynonenal on day 4 and of a hydroxyaldehyde with a chromatographic behavior very similar to 4-HNE on day 8. We conclude that celiptium induced a preferential decrease of phosphatidylethanolamine linked to the formation of unsaturated free fatty acids and of 4-hydroxyalkenals. The toxic side-effects of these breakdown products produced in the proximal tubular cell are discussed in light of the lipid peroxidation process involved in the renal toxicity of celiptium.     

Probing intercalation and conformational effects of the anticancer drug 2-methyl-9-hydroxyellipticinium acetate in DNA fragments with circular dichroism.

Circular dichroism was applied to the analysis of drug-DNA associations. With the octanucleotide d(TGACGTCA) (octanucleotide I), which is the cAMP-responsive element (CRE) in gene promoters and its reverse d(ACTGCAGT) (octanucleotide II), it was demonstrated that the anticancer polyaromatic agent celiptium intercalates into DNA base pairs with its long direction perpendicular to both the DNA-helix axis and the base-pair long axis and induces larger conformational changes in the CpG-containing octanucleotide I CRE than in its reverse-sequence octanucleotide II. It was concluded that CD is a powerful and sensitive technique to discriminate between drug-binding modes of DNA, to define the geometry of the chromophore inserted into base pairs and, finally, to measure sequence-dependent conformational changes induced by intercalation in DNA. We anticipate that these studies will contribute to a better understanding of the molecular bases that underlie the mechanism of action of those cytotoxic drugs which interfere with the DNA-nuclear-protein recognition.     

Adrenal cortex and micro-RNAs

Comment on: Iliopoulos D, et al. Cancer Res. 2009; 69:3278-82.     

Characterization of 4-methyl-2-oxo-1,2-dihydroquinolin-6-yl acetate as an effective antiplatelet agent

We have studied earlier a membrane bound novel enzyme Acetoxy Drug: protein transacetylase identified as Calreticulin Transacetylase (CRTAase) that catalyzes the transfer of acetyl groups from polyphenolic acetates (PAs) to the receptor proteins and thus modulating their biological activities. In this communication, we have reported for the first time that acetoxy quinolones are endowed with antiplatelet action by virtue of causing CRTAase catalyzed activation of platelet Nitric Oxide Synthase (NOS) by way of acetylation leading to the inhibition of ADP/Arachidonic acid (AA)-dependent platelet aggregation. The correlation of specificity of platelet CRTAase to various analogues of acetoxy quinolones with intracellular NO and consequent effect on inhibition of platelet aggregation was considered crucial. Among acetoxy quinolones screened, 6-AQ (4-methyl-2-oxo-1,2-dihydroquinolin-6-yl acetate/6-acetoxyquinolin-2-one, 22) was found to be the superior substrate to platelet CRTAase and emerged as the most active entity to produce antiplatelet action both in vitro and in vivo. 6-AQ caused the inhibition of cyclooxygenase-1 (Cox-1) resulting in the down regulation of thromboxane A2 (TxA2) and the inhibition of platelet aggregation. Structural modification of acetoxy quinolones positively correlated with enhancement of intracellular NO and antiplatelet action.     

Synthesis and antitumor activities of 5-methyl-1- and 2-[[2-dimethylaminoethyl]amino]-aza-thiopyranoindazoles

The synthesis of 1- and 2-substituted aza-benzothiopyranoindazoles has been accomplished. The comparisons of the in vitro antitumor activities of the 2-substituted analogues with the benzothiopyranoindazole chemotypes indicate that the positioning of the nitrogen atom at C-9 (9-aza analogue 4d) leads to a substrate with potent antitumor activity. The 1-substituted aza-benzothiopyranoindazoles, in comparison with the corresponding 2-substituted analogues, exhibit a much lower potency.     

原发性肾上腺非霍奇金淋巴瘤（附9 例报告）

目的:探讨原发性肾上腺淋巴瘤(Primary Adrenal Lymphoma,PAL)的临床特点、提高对PAL的认识。方法:回顾分析解放军总医院1995年12月至2007年6月收治的9例PAL的临床表现、实验室检查、影像学特点、组织病理类型以及治疗方法等临床资料,并结合国内外文献进行分析。结果:9例患者中,1例因常规体检发现,8例因腹痛、腹胀或腰痛就诊发现;其中单侧3例,双侧6例,实验室检查无明显异常,影像学检查仅发现肾脏肿瘤,但术后病理组织学诊断为非霍奇金淋巴瘤(non-Hodgkin’s lymphoma,NHL),其中8例弥漫大B细胞淋巴瘤,1例T细胞淋巴瘤;7例患者术后均接受了CHOP或RCHOP方案化疗为主的综合治疗,2例常规治疗;随访至2010年2月,1例弥漫性大B细胞淋巴瘤患者存活4年,1例在术后3年2个月死亡,余7均在2年内死亡。结论:PAL是一种罕见的、恶性程度较高的肿瘤,临床表现和影像学检查缺乏特异性,组织病理学及免疫组织化学是明确诊断的好方法。术前确诊肾上腺原发性非霍奇金淋巴瘤可避免手术,联合化疗应为治疗首选。     

Selective catalytic reduction of 7-methyl-6-dehydrotestosterone acetate to 7 beta-methyltestosterone acetate by benzyl alcohol.

Using benzyl alcohol as a hydrogen donor in the presence of Pd on charcoal, 7-methyl-6-dehydrotestosterone acetate was selectively reduced to 7 beta-methyltestosterone acetate in 90% yield. The addition of hydrogen atoms to the 6, 7 double bond proceeded from the less hindered alpha-face of the steroid molecule, giving rise to the 7 beta-methyl product. Gas chromatograph analysis indicated small amounts of the 7 alpha-methyl epimer, 7 beta-methyl-5 alpha-dihydrotestosterone acetate and the 5 beta-epimer. The 6,7 double bond was hydrogenated in preference to 4,5 double bond, although both are trisubstituted.     

Synthesis of racemic 9-methyl-10-hexadecenoic acid

The marine bacterial fatty acid 9-methyl-10-hexadecenoic acid was conveniently prepared in 6 steps and in a 22% overall yield, starting from commercially available methyl 10-hydroxydecanoate. The naturally occurring fatty acid has the E double bond configuration as confirmed by gas chromatographic co-elution experiments.     

Synthesis and activities of 9-pyrrolo-9-deoxoerythromycin a analogs

Preparation of novel 9-pyrrolo-9-deoxoerythromycin A analogs from 9-(S) and (R, erythromycylamines by the Clauson-Kass and Wasserman reactions is described. The biological activities of these novel analogs are also reported.     

Design, synthesis and antimycobacterial activities of 1-methyl-2-alkenyl-4(1H)-quinolones

A series of 23 new 1-methyl-2-alkenyl-4(1H)quinolones have been synthesized and evaluated in vitro for their antimycobacterial activities against fast growing species of mycobacteria, such as Mycobacterium fortuitum, M. smegmatis and M. phlei. The compounds displayed good to excellent inhibition of the growth of the mycobacterial test strains with improved antimycobacterial activity compared to the hit compound, evocarpine. The most active compounds, which possessed chain length of 11-13 carbons at position-2 displayed potent inhibitory effects with an MIC value of 1.0 mg/L. In a human diploid embryonic lung cell line, MRC-5 cytotoxicity assay, the alkaloids showed weak to moderate cytotoxic activity. Biological evaluation of these evocarpine analogues on the less pathogenic fast growing strains of mycobacteria showed an interesting antimycobacterial profile and provided significant insight into the structure-activity relationships.     

Reactions of chloride salts of 7-amino-9-ethylguanine and 1-amino-3-methylbenzimidazoles with lead(IV) acetate: formation of 8-aza-9-ethylguanine and 1-methyl-1H-benzotriazoles

Reaction of 7-amino-9-ethylguaninium chloride with lead(IV) acetate (LTA) in MeOH yielded 8-aza-9-ethylguanine. Similarly, the reaction of 1-amino-3-methylbenzimidazolium chloride or its substituted derivatives (6-methyl, 5,6-dimethyl and 5-nitro) with LTA gave the corresponding 1-methyl-1H-benzotriazole (or 1-methyl-2-azabenzimidazole) derivatives along with N-methylformananilide derivatives.     

Radioprotective activity and toxicity of copolymer 2-methyl-5-vinyl pyridine with 2-methyl-5-vinylpyridinium-n-oxide

In experiments in mice, hamsters and dogs therapeutic radioprotective efficiency and toxicity of new water-soluble copolymer were studied. It was found that at intramuscular injection of the copolymer to dogs in a dose of 5 mg/kg 24 h after irradiation with a dose of 3.30 Gy (LD85/45) it showed pronounced therapeutic effect (68.1%). In mice and hamsters, the effect was less pronounced: 42-21% after irradiation with a dose of 8.0 Gy. The copolymer is low toxic substance and according to the State standards of Russian Federation belongs to the fourth class (harmless).     

Peroxidase-catalyzed covalent binding of the antitumor drug N2-methyl-9-hydroxyellipticinium to DNA in vitro

In the presence of DNA, the antitumor drug N2-methyl-9-hydroxyellipticinium (elliptinium; NMHE) [Le Pecq, J. B., Gosse, C., Dat-Xuong, N., & Paoletti, C. (1975) C. R. Seances Acad. Sci., Ser. D 281, 1365-1367] is oxidized by the horseradish peroxidase-hydrogen peroxide (HRP-H2O2) system to the quinone imine derivative N2-methyl-9-oxoellipticinium (NMOE) [Auclair, C., & Paoletti, C. (1981) J. Med. Chem. 24, 289-295], which interacts with DNA according to the intercalation mode. When excess H2O2 was used, the major part of the quinone imine was further oxidized to the o-quinone N2-methyl-9,10-dioxoellipticinium [Bernadou, J., Meunier, G., Paoletti, C., & Meunier, B. (1983) J. Med. Chem. 26, 574-579]. In the presence of stoichiometric amounts of H2O2 (H2O2/NMHE = 1), NMOE reacts with DNA, yielding a fluorescent compound irreversibly linked to the nucleic acid, which is related to the covalent binding of the ellipticinium chromophore. Under optimal reaction conditions, NMHE binding occurs according to a first-order process (k = 4.3 X 10(-3) min-1) with a linear increase with respect to drug to nucleotide ratio up to a maximum binding of 1 NMHE per 20 base pairs (r = 0.05). The fluorescence spectra (ex, 330 nm; em, 548 nm) of NMHE bound to DNA, the occurrence of energy transfer from the DNA to the drug, and the DNA length increase of the DNA-NMHE adduct suggest that the binding occurs at the intercalating site with limited denaturation of the DNA helix.(ABSTRACT TRUNCATED AT 250 WORDS)     

Anti-masculinizing action of estradiol and cyproterone acetate: regulation of a protein fraction with phospholipase-A2 stimulatory and masculinizing activities

Recently we have identified a protein fraction (55-63 K) from male and testosterone-exposed female mouse genital tract, which stimulates phospholipase A2 (PLA2) and induces masculine differentiation in an undifferentiated mouse genital explant, suggesting a role of this protein in the action of testosterone. In the current study we have further investigated the role of this protein by determining whether anti-masculinizing agents, namely, estradiol and cyproterone acetate, have any effect on the production of this protein. The results described here indicate that a protein fraction containing PLA2 stimulatory activity was present in both control male and estradiol- or cyproterone acetate-exposed male fetal genital tract. However the specific activity of the PLA2-stimulatory protein was significantly higher in the control males than in the experimental males. We did not find any major difference in the behavior of this protein fraction in various chromatographic steps except that in CM-sepharose column; the PLA2-stimulatory activity from the male preparation was eluted in two overlapping peaks with 0.3 and 0.25 M NaCl and that from the treated males was eluted only with 0.25 M NaCl. The SDS-gel analysis of this protein fraction revealed a doublet band (55 and 63 K) in control samples and primarily a 63 K band in experimental samples. The protein fraction from all these sources showed a significant difference in their biological activity. The control male preparation induced Wolffian duct whereas the estradiol sample was completely ineffective and the cyproterone acetate sample was partially effective in inducing Wolffian duct. Thus, it appears that the protein fraction has a role in the masculinizing action of testosterone.