Liquid Chromatographic Determination of Glyphosate in Water-Soluble Granular Formulations: Collaborative Study

A liquid chromatographic (LC) method for the determination of glyphosate in various water-soluble granular formulations was tested by 28 laboratories. Samples were dissolved in mobile phase and injected directly into an LC system with a 25 cm SAX column and a mobile phase of 96% aqueous buffer solution, 0.0062M KH2PO4, and 4% methanol. Detection was by UV absorption at 195 nm. Manual or automated injections were made via fixed-volume loops. Calculations were based on peak area comparisons with external standards. The collaborative study analyzed 5 matched pairs of 4 water-soluble granular formulations, with one determination per sample. The study generated 138 matched pairs, which were analyzed by using the AOAC spreadsheet and Youden’s matched-pair calculations. Coefficients of variation for the 4 formulations ranged from 0.65 to 1.37%. The LC method for the determination of glyphosate in water-soluble granular formulations has been adopted first action by AOAC INTERNATIONAL.

Differentiating between primary and secondary Sertoli-cell-only syndrome by histologic and hormonal parameters

The contribution of histologic differentiation between primary and secondary Sertoli-cell-only (SCO) syndrome in azoospermic men was evaluated. No correlation was found between the presence of sperm cells in the testis and the histologic findings or inhibin B or FSH levels, suggesting a low prognostic value for this differentiation.

Mechanistic aspects of DNA damage by morpholinyl and cyanomorpholinyl anthracyclines

Morpholino and cyanomorpholino derivatives of the anthracycline antitumor antibiotics, Adriamycin (ADM) and daunomycin (DNM), differ from their parent compounds in potency, cross-resistance and other biological properties. We therefore investigated the DNA interactions of several derivatives of ADM and DNM, including iminomorpholinoadriamycin, oxazolocyanomorpholinoadriamycin, (OCADM), and cyanomethyladriamycin (CMeADM). This work complements previous studies on morpholinodaunomycin (MoDNM), morpholinoadriamycin (MoADM), and cyanomorpholinoadriamycin (CNMoADM). As described in this work, unscheduled DNA synthesis is induced by iminomorpholinoadriamycin, 5-iminocyanomorpholinoadriamycin (ICADM), OCADM, and CMeADM but not by ADM and DNM. In addition, we observed the induction of DNA single-strand breaks by ICADM, OCADM, and CMeADM in V79 cells; previous work has shown that ADM and DNM but not MoDNM induce single-strand breaks in these cells. DNA cross-links were induced by ICADM at high concentrations (greater than 50 nM) but not by MoADM, OCADM, and CMeADM as described herein. In previous investigations, we observed that CNMoADM and cyanomorpholinodaunomycin (CNMoDNM) but not ADM, DNM, and MoDNM induce DNA cross-links. CNMoADM and CNMoDNM are the most potent cytotoxic derivatives of ADM and DNM and have their cross-linking potential in common. The fact that CNMoADM and CNMoDNM (as well as ICADM at higher concentrations) all contain an alpha-cyanamide functionality and also yield cross-links suggests that this functionality is important for cross-linking. The CN moiety in [14C]N-MoADM was shown to be lost during the reaction with DNA and rat liver S9 (but not with buffer), which suggests that adduction via CN displacement is possible. On the other hand, OCADM and CMeADM both contain the alpha-cyanamine functionality but have a modified morpholino ring and do not yield cross-links. This suggests that an intact morpholino ring, which is metabolized to a reactive form, is necessary for cross-linking. A number of metabolites from MoDNM treated with rat liver S9 mix were isolated. These products, when analyzed by gas chromatography-mass spectrometry, are consistent with metabolism in the morpholino ring; however, definitive structural assignments could not yet be made.

Separation of racemic pharmaceuticals by high-performance liquid chromatography on silica gel modified with carbohydrate residues

Derivatives of 2-amino-2-deoxyglucose covalently connected to aminopropyl-silica gel were used as chiral selectors in the separation of racemic pharmaceuticals. beta-Receptor blockers, adrenergic drugs and compounds with secondary amino functions could be separated after appropriate derivatization.