Monitoring of progestins: development of immunochemical methods for purification and detection of levonorgestrel.

A polyclonal antibody (Ab) for the progestin levonorgestrel (LNG) was generated, and immunochemical assays for its detection, clean-up and concentration were developed. A highly specific microplate diagnostic assay for the detection of LNG was developed that used the enzyme linked immunosorbent assay (ELISA) method. The LNG ELISA developed was sensitive and reproducible; it exhibited I(50) and I(20) values of 3.3+/-1.8 ng mL(-1) and 0.6+/-0.4 ng mL(-1), respectively, and the Abs did not cross react with any of the tested steroid hormones. The above Abs were used to develop a sol-gel-based immunoaffinity purification (IAP) method for concentration and clean-up of LNG that is compatible with subsequent immunochemical or instrumental chemical analytical procedures, such as liquid chromatography followed by mass spectrometry (LC-MS/MS). Development of the columns included successful entrapment of Abs within a tetramethoxysilane (TMOS)-based SiO(2) polymer network. The Abs could bind the free analyte from solution, and the bound analyte could be easily eluted from the sol-gel matrix at high recoveries. The Ab selectivity towards the antigen was high, in both ELISA and the sol-gel columns, but the entrapped Abs cross-reacted with two other steroid hormones--ethynylestradiol (EE2) and nortestosterone (NT) - which share similar epitopes with LNG, despite the lack of cross reactivity in the ELISA. The validity of the method was investigated by LC-MS/MS and a good analytical correlation was obtained.

Aryl chain analogues of the biotin vitamers as potential herbicides. Part 3.

Novel aryl chain isosters and analogues of 7-keto-8-aminopelargonic acid (KAPA) and 7,8-diaminopelargonic acid (DAPA), the vitamer intermediates involved in the biosynthetic pathway of biotin, possessing chain lengths of eight carbon atoms, were prepared and evaluated as potential herbicides. In the greenhouse test the most active compounds were the fluorinated derivative 9d and the selenophenyl/furan mixture 17m/17p, which were most active against Foxtail millet. In the more sensitive Arabidopsis test the most active substances were 9a and 17m, which displayed GR(50) (concentration of active compound causing 50% growth inhibition) values of 0.2 and 0.5 mg kg(-1) respectively (values of < 50 mg kg(-1) are considered herbicidal).

AN-113, a novel prodrug of 4-phenylbutyrate with increased anti-neoplastic activity in glioma cell lines.

Butyroyloxymethyl-4-phenylbutyrate (AN-113) is a novel HDACI that releases potent anti-neoplastic derivatives upon intracellular hydrolysis. The precursor of AN-113, 4-phenylbutyrate has shown promising results in a Phase I study of gliomas, and we hypothesized that AN-113 offers significant advantages over the parent drug. AN-113 demonstrates selective in vitro cytotoxicity against malignant cells while sparing normal astrocytes, effective at doses over 20-fold lower than 4-phenylbutyrate. Combining AN-113 and radiation results in additive therapeutic effects. Enthusiasm is lent to this approach by the ability of AN-113 to efficiently kill glioma cells, its bioavailability and potency when administered orally, its capacity to cross the blood-brain barrier, and its effectiveness in combination with radiation.