Facile and efficient access to Androsten-17-(1',3',4')-pyrazoles and Androst-17ß-(1',3',4')-pyrazoles via Vilsmeier reagents, and their antiproliferative activity evaluation in vitro.

In this work, twenty-seven novel steroidal pyrazole derivatives were designed and effectively synthesized with two different commercially available staring material, Isopregnanolone 1 and 5,16-Pregnadienolone 7, via the key intermediates, 17ß-(4'-formyl)pyrazolylandrost-3ß-yl formate and 17-(4'-formyl)pyrazolylandrost- 5,16-dienes-3ß-yl formate, which were obtained from the cyclization of steroidal phenylhydrazone with Vilsmeier reagent catalyzed by phosphorous oxychloride followed by hydrolysis, then Borch reduction to afford the target derivatives under mild conditions. Structures of these compounds were identified by 1H NMR, 13C NMR and high resolution mass spectrometry. Based on our previous work, the cytotoxicity of these derivatives were evaluated by the SRB method against 293T cell lines and three cancer cell lines: A549, Hela and MCF-7. The results indicated that compounds 5b-d, and 11a-e exhibited moderate to high cytotoxic activities with IC50 values ranging from 0.62 to 7.51 µM. Among the eight hybrids, compound 11b, with an ethyl amino and a dien-pregn moieties showed the highest potency, with an IC50 values of 0.87 µM and 0.53 µM for 293T cell lines and Hela cell lines, respectively. Some structure-activity relationships among the groups of the twenty-seven derivatives are discussed and identify several determinants important for the activity of these compounds. What's more, further molecular mechanism studies suggested that 11b one of the most potent derivatives caused Hela cell lines apoptosis and arrested the cell cycle at S phase in a concentration dependent manner.

Insight into the Mode of Action of Haedoxan A from Phryma leptostachya.

Haedoxan A (HA) is a major active ingredient in the herbaceous perennial plant lopseed (Phryma leptostachya L.), which is used as a natural insecticide against insect pests in East Asia. Here, we report that HA delayed the decay rate of evoked excitatory junctional potentials (EJPs) and increased the frequency of miniature EJPs (mEJPs) on the Drosophila neuromuscular junction. HA also caused a significant hyperpolarizing shift of the voltage dependence of fast inactivation of insect sodium channels expressed in Xenopus oocytes. Our results suggest that HA acts on both axonal conduction and synaptic transmission, which can serve as a basis for elucidating the mode of action of HA for further designing and developing new effective insecticides.

Larvicidal activity of lignans from Phryma leptostachya L. against Culex pipiens pallens.

The larvicidal activity of crude petroleum ether, ethyl acetate, and methanol extracts of the whole plants of Phryma leptostachya L. was assayed for its toxicity against the early fourth instar larvae of Culex pipiens pallens. The larval mortality was observed after 24 h of exposure. Among three solvent extracts from Phyrma leptostachya L., the petroleum ether extract exhibited the best larvicidal activity. The corresponding LC50 values of petroleum ether, ethyl acetate, and methanol extracts were 3.23, 5.23, and 61.86 ppm against the early fourth instar larvae of Culex pipiens pallens. The petroleum ether extract was successively subjected to column chromatography and preparative high performance liquid chromatography, and yielded the three lignans, phrymarolin-I, haedoxane A, and haedoxane E, which were isolated and identified as new mosquito larvicidal compounds. Phrymarolin-I, haedoxane A, and haedoxane E showed high larvicidal activity, for which the lethal doses LC50 were estimated at 1.21, 0.025, and 0.15 ppm against the early fourth instar larvae of Culex pipiens pallens, respectively. The structures were elucidated by analyses of IR, UV, MS, and NMR spectral data. This is the first report on the mosquito larvicidal activity of the three compounds, phrymarolin-I, haedoxane A, and haedoxane E from Phyrma leptostachya L.

Histological study of vas deferens following intravasal laser irradiation.

AIM: To study the histologic changes of the vas deferens following Nd: YAG laser irradiation. METHODS: Intravasal laser irradiation was given to (i) 52 segments of rabbit (laser dosage: 2 seconds at 40 W approximately 50 W) and 16 segments of human (3 seconds at 45 W approximately 55 W) vas deferens in vitro, (ii) 25 rabbit vasa (2 seconds approximately 2.5 seconds at 40 W approximately 45 W) in vivo and (iii) 2 human vasa (3 seconds at 55 W) in vivo. Segments of vasa were removed from the in vivo irradiated vasa deferentia 15 days approximately 180 days (rabbit) or 15 days (man) after the exposure. All vas segments were embedded in methacrylate resin. Serial sections (thickness 25 microm approximately 30 microm) were obtained and observed under a light microscope. RESULTS: (i) Laser-induced damage reached the muscularis layer in 27% and 94% of the rabbit and human vas segments in vitro, respectively. (ii) Fourteen of the 25 in vivo rabbit vasa were completely occluded by fibrous tissue and the longer the time interval after treatment, the more likely was the vas occluded. Those unoccluded vasa had either a normal histology or a mucosal damage. (iii) One in vivo human vas was almost completely occluded by the fibrous tissue but the other had a relatively large lumen packed with sperm granulomatous tissue and partial destruction of the smooth muscle layer. CONCLUSION: Laser irradiation can induce long-term vas occlusion; for rapid occlusion, laser doses just completely destroying the mucosal layer will be advisable.