PREPARATION OF B-CYCLODEXTRIN-THIABENDAZOLE-PIPERONYL BUTOXIDE SUPRAMOLECULAR COMPLEX AND ITS ACTIVITY AGAINST BLUE AND GREEN MOULD DECAY ON INOCULATED SATSUMA FRUIT.

The supramolecular complex of ß-cyclodextrin-thiabendazole-piperony butoxide (ßCD-TBZ/PBO) was prepared and its structure was characterized by 1H NMR. Additionally, the antifungal activity of ßCD-TBZ/PBO was investigated in comparison with the commercially available thiabendazole (TBZ) fungicide by in vitro tests and on artificially inoculated 'Okitsu' satsuma fruit dipped in water at 20 degrees C or at 50 degrees C to control postharvest blue (Penicillium italicum) and green mould (P. digitatum). ß-CD-TBZ/PBO is stable for several months when stored as powder in a dark bottle. At pH 7.0 the water solubility of the ßCD-TBZ/PBO complex was consistently higher than free TBZ. Water dip at 20 degrees C did not affect decay incidence caused by blue mould but favoured the development of green mould during 4-8 days of storage at 20 degrees C with respect to untreated (control) fruit. Water at 50 degrees C effectively reduced the incidence of blue mould and totally suppressed green mould during the first 4 days but lost its efficacy afterwards. By contrast, both TBZ and ßCD-TBZ/PBO had a lasting effect and were equally effective in controlling green and blue mould decay when applied at 20 degrees C and 60 mg L(-1) active ingredient (a.i.). When applied at 50 degrees C and 20 mg L(-1) a.i. the activity of the complex against blue mould was inferior than the corresponding treatment with TBZ. In vitro assays revealed a significant effectiveness of ßCD-TBZ/PBO complex at low concentration compared to commercial formulation of TBZ.

Liquid chromatography-tandem mass spectrometry for the identification of impurities in d-allethrin samples.

A previous GC/MS study highlighting the impurity profile of the synthetic pesticide d-allethrin is extended here to validate and confirm the impurities identity through the development of soft ionisation HPLC-MS methods. To accomplish this, we developed a reverse phase LC-MS analysis in gradient elution with two distinct soft ionisation techniques, the atmospheric pressure ionisation with electrospray source (API-ESI) and the chemical ionisation (APCI). A single quadrupole and an ion trap, which allowed the simultaneous determination of the molecular masses and structural information of the impurities by acquisition of collisionally induced (CID) product ions spectrum and in-source fragmentation, were employed as analysers. Single quadrupole and ion trap analysers resulted perfectly matching in the d-allethrin impurity fragmentation patterns. All the main impurities over 0.1% identified by GC/MS were confirmed. Results indicate that the proposed HPLC/MS method was found appropriate to confirm the presence of impurities such as chrysolactone, chloro allethrin derivatives, allethrolone and chrysanthemic acid, excluding their formation under GC/MS strong ionisation condition.

Stereoselective determination of allethrin by two-dimensional achiral/chiral liquid chromatography with ultraviolet/circular dichroism detection.

A two-dimensional achiral/chiral HPLC method with circular dichroism (CD) detection was optimized for the stereochemical resolution and determination of the elution order of the eight stereoisomers of synthetic allethrin. A monolithic silica HPLC column (Chromolith, Merck, 100 mm x 4.6 mm i.d.) was put orthogonally to an enantioselective OJ Daicel column (250 mm x 4.6 mm i.d.) by means of a switching valve. The resolution of cis and trans diastereoisomers on the silica column was obtained by using a mobile phase consisting of n-hexane:tert-butyl methyl ether (96:4) (v/v) at a flow rate of 1 ml min(-1). The cis and trans peaks were then switched to the enantioselective OJ column separately in two subsequent injections. The resolution of the four trans stereoisomers was accomplished by using n-hexane:tert-butyl methyl ether (90:10) (v/v), while the mobile phase composition for the four cis stereoisomers consisted of n-hexane:isopropanol (99.3:0.7) (v/v). The CD based detection system allowed the determination of the elution order on the basis of the CD signals of the single stereoisomers, together with the injection of pure stereoisomers. Under the final conditions, the validated method was applied to the determination of stereoisomeric composition and absolute configuration of the prevailing stereoisomers of real samples, i.e. commercial batches of different sources of d-allethrin.

The effects of hypolipidemic agents derived from procetofenic acid on the activity of superoxide dismutase and glutathione peroxidase and on malonyl dialdehyde production of rat liver.

Male and female rats were treated with hypolipidemic agents derived from procetofenic acid, namely fenofibrate ( procetofene ), cholestyrammonium alpha-(4-p-chlorobenzoyl-phenoxy)-isobutyrate (Alfa-1081) and alpha-(4-p-chlorobenzoyl-phenoxy)-isobutyryl-taurine (35/ipo). A marked decrease of liver superoxide dismutase and glutathione peroxidase was observed in the male rats treated with fenofibrate. In this sample a significant increase of malonyl dialdehyde was also detected when the liver homogenates were subjected to a test of lipid peroxidation induced by active oxygen species. Alfa-1081 and 35/ipo produced no substantial changes of superoxide dismutase and glutathione peroxidase and no significant increase of peroxidation products. These results, while providing an in vivo evidence for the role of superoxide dismutase and glutathione peroxidase as antioxidant enzymes, indicate that hypolipidemic agents can affect also enzymes not bound to membranes as they do with peroxisomal enzymes. The side effect presented here may be harmful, since it can lead to an augmented risk of lipid peroxidation in tissues. It is, however, clear that also within the same class of hypolipidemic drugs the effect is not always present. Peroxidative damage should therefore be considered as a key parameter in the characterization of hypolipidemic agents.

Effects of a salt of cholestyramine and 2-[4-(p-chlorobenzoyl)phenoxy]2-methyl propionic acid (alpha-1081) on biliary lipid secretion in rats.

1 Hypolipidaemic agents may increase biliary cholesterol in man, inducing a supersaturated bile. 2 To evaluate this possible side-effect, we have studied bile lipid secretion over a period of 8 h with intact enterohepatic circulation and 4 h with complete interruption in rats treated for two months with a salt of cholestyramine and 2-[4-(p-chlorobenzoyl)-phenoxy]2-methyl propionic acid (alpha-1081, 1.150 g/kg body wt., daily), cholestyramine (1.125 g/kg body wt. daily), procetofenic acid (25 mg/kg body wt. daily) and saline respectively (six rats for each group). 3 Cholesterol saturation index significantly (P less than 0.005) increased (from 0.21 +/- 0.01 to 0.39 +/- 0.09, mean +/- s.d.), in rats fed with procetofenic acid but it did not in alpha-1081- and cholestyramine-treated animals. 4 Procetofenic acid and, to a lesser extent, cholestyramine increased the bile flow. Procetofenic acid increased cholesterol secretion from 0.45 +/- 0.17 to 0.94 +/- 0.19 mumol kg-1 body wt. h-1 (mean +/- s.d.). 5 Cholestyramine increased both serum cholesterol and bile acid secretion from 0.45 +/- 0.17 to 0.68 +/- 0.10 and 25.8 +/- 9.48 to 39.96 +/- 6.68 mumol kg-1 body wt. h-1 respectively; alpha-1081, on the contrary, had no effect on bile lipid secretion. 6 These data suggest that alpha-1081 may be used as a new hypolipidaemic drug without any risk of increasing cholesterol in bile.