Plant extracts traditionally used for male impotence (Tribulus terrestris, Ferula hermonis, Epimedium breVicornum, Cinnamomum cassia), and the individual compounds cinnamaldehyde, ferutinin, and icariin, were screened against phosphodiesterase-5A1 (PDE5A1) activity. Human recombinant PDE5A1 was used as the enzyme source. Only E. breVicornum extract (80% inhibition at 50 µg/mL) and its active principle icariin (1) (IC 50 5.9 µM) were active. To improve its inhibitory activity, 1 was subjected to various structural modifications. Thus, 3,7-bis(2-hydroxyethyl)icaritin (5), where both sugars in 1 were replaced with hydroxyethyl residues, potently inhibited PDE5A1 with an IC 50 very close to that of sildenafil (IC 50 75 vs 74 nM). Thus, 5 was 80 times more potent than 1, and its selectivity versus phosphodiesterase-6 (PDE6) and cyclic adenosine monophosphate-phosphodiesterase (cAMP-PDE) was much higher in comparison with sildenafil. The improved pharmacodynamic profile and lack of cytotoxicity on human fibroblasts make compound 5 a promising candidate for further development.The inability to achieve or maintain an erection sufficient for satisfactory sexual function is an increasing problem with a considerable impact on interpersonal relationships and quality of life for men.1 During erection, nitric oxide is released from the axon terminals of the parasympathetic nerves and diffuses into smooth muscle cells of the arterial walls of the corpus cavernosum. The consequent activation of guanyl cyclase, converting guanosine triphosphate (GTP) into cyclic guanosine monophosphate (cGMP), causes smooth muscle relaxation, leading to dilation and increased influx of blood into the penile tissue. The trapping of blood in the penis results in an erection.2 Selective inhibitors of cGMPphosphodiesterase-5 (PDE5) such as sildenafil (Viagra), tadalafil, and vardenafil are currently used for erectile dysfunction (ED). However, several adverse effects have been recorded in clinical trials, including priapism and visual disturbances.3 Furthermore, therapy with PDE5 inhibitors is cost-effective. Thus, the search for new compounds of this type for drug development could be worthwhile. A variety of natural plant products, including berberine, forskolin, papaverine, and yohimbine, are claimed to be useful for improving sexual performance. Extracts from Lepidium meyenii Walp. (maca), Panax ginseng C.A. Meyer, Ginkgo biloba L., Ferula hermonis Boiss., and many other herbal remedies, alone or in combination, have been promoted for the treatment of sexual problems. 4,5 With the aim of looking for new leads for selective PDE5 inhibitors, plant extracts and their putative active principles were selected for screening against human PDE5 activity in vitro. Our attention focused on Tribulus terrestris L., Ferula hermonis, Epimedium breVicornum Maxim., and Cinnamomum cassia L., since these extracts are claimed traditionally to improve sexual performance. T. terrestris caused vasodilating and antihypertensive effects in rats 6 and a pro-erectile eff...

No abstract

The marine dinojlagellates Prorocentrum micans, Gonyaulax polyedra, Gymnodinium sp., and Alexandrium tamarense, collected from the Adriatic Sea during red-tide blooms, were cultured to investigate the 4-methy l sterol constituents. To ascertain a possible influence of cell age on the 4-methyl sterol content, for one strain (Gymnodinium sp.) we investigated the composition of these constituents at exponential and stationaly growing phases. The lipid material extracted with acetone from the lyophilized algal samples was fractionated by thin-layer chre matography. The 4-methyl sterols recovered from the layer were converted into the corresponding OTMS derivatives. Nine of 11 constituents were identified by gas chromatography and gas chromatography-mass spectromet?y; only two minor constituents were characterized by their gas chromatographic parameters. All free methyl sterols identzjied in the algal samples had been detected previously in various dinoflagellates. The 4-methyl sterol fractions generally

High-performance liquid chromatography with fluorescence detection was used for the analysis of polycyclic aromatic hydrocarbons (PAHs), in "Diavoletto" smoked cheese. Such cheese is typically produced in the Sorrento peninsula, and it is smoked commonly with different materials of vegetable origin. The importance of the smoking generation material is proven by the attention that the EU is paying in indicating the list of wood that may be used to produce smoking flavor agents. The PAHs considered are classified as "probable human carcinogens" by the U.S. Environmental Protection Agency for sufficient data from animal bioassays. The smoked samples contained high molecular mass PAHs with different levels ranging from 0.12 to 6.21 microg/kg. The determination was carried out also on liquid smoking flavor agents, smoke-flavored cheese, and nonsmoked cheese to measure the level of contamination before the treatment.