Levels and seasonal variations of organochlorine pesticides in urban and rural background air of southern Ghana.

Urban, suburban and rural background air samples were collected in southern Ghana in 2008 employing polyurethane foam disc passive air samplers (PAS). PAS were analysed for organochlorine pesticides (OCPs), namely hexachlorocyclohexanes (α-, β-, γ- and δ-hexachlorocyclohexane), dichlorodiphenyltrichloroethane including metabolites (o,p'- and p,p'-DDT, DDE and DDD), hexachlorobenzene, pentachlorobenzene, aldrin, dieldrin, endrins (endrin, endrin aldehyde and endrin ketone), isodrin, heptachlors (heptachlor, heptachlor epoxide A and heptachlor epoxide B), chlordanes (α-, β-chlordane, oxychlordane and trans-nonachlor), endosulfans (α- and β-endosulfan and endosulfan sulphate), methoxychlor and mirex using a gas chromatograph coupled to a mass spectrometer. The levels of OCPs ranged for the individual pesticides from below limit of quantification to 750 pg m(-3) (for α-endosulfan), and current agricultural application seemed to be the main primary source of most abundant pesticides.

Covalent bonding of azoles to quaternary protoberberine alkaloids.

Adducts of the quaternary protoberberine alkaloids (QPA) berberine, palmatine, and coptisine were prepared with nucleophiles derived from pyrrole, pyrazole, imidazole, and 1,2,4-triazole. The products, 8-substituted 7,8-dihydroprotoberberines, were identified by mass spectrometry and 1D and 2D NMR spectroscopy, including (1)H--(15)N shift correlations at natural abundance. In addition, two adducts of QPA with chloroform and methanethiolate were characterized by using NMR data.

Chemoprotective and toxic potentials of synthetic and natural chalcones and dihydrochalcones in vitro.

Cytochrome P4501A activity, oxidative stress and inhibition of gap junctional intercellular communication (GJIC) are involved in metabolic activation of promutagens and tumor-promoting activity of various xenobiotics, and their prevention is considered to be an important characteristic of chemoprotective compounds. In this study, a series of 31 chalcones and their corresponding dihydroderivatives, substituted in 2,2'-, 3,3'-, 4- or 4'-position by hydroxyl or methoxy group, were tested for their ability to inhibit Fe(II)/NADPH-enhanced lipid peroxidation and cytochrome P4501A-dependent 7-cethoxyresorufin-O-deethylase (EROD) activity in rat hepatic microsomes. Effects of the compounds on GJIC were determined in rat liver epithelial WB-F344 cells.