The measurement of trace levels of bisphenol A (BPA) leached out of household plastics using solid-phase microextraction (SPME) with gas chromatography−mass spectrometry (GC−MS) is reported here. BPA is an endocrine-disrupting compound used in the industrial manufacture of polycarbonate plastic bottles and epoxy resin can liners. This experiment allows students to use modern instrumentation and analytical techniques to investigate a timely and relevant issue involving the contamination of food products by a packaging component. The impact of handling conditions and container type on the quantity of BPA released from the plastics is explored. This experiment is suitable for an undergraduate analytical chemistry or instrumental analysis course and requires two, 3-h laboratory periods to complete.

Mosberg HI, Schmaier AH. Thrombostatin FM compounds: direct thrombin inhibitors -mechanism of action in vitro and in vivo. J Thromb Haemost 2008; 6: 837-45.Summary. Background: Novel pentapeptides called Thrombostatin FM compounds consisting mostly of D-isomers and unusual amino acids were prepared based upon the stable angiotensin converting enzyme breakdown product of bradykinin -RPPGF. Methods and Results: These peptides are direct thrombin inhibitors prolonging the thrombin clotting time, activated partial thromboplastin time, and prothrombin time at ‡0.78, 1.6, and 1.6 lM, respectively. They competitively inhibit a-thrombin-induced cleavage of a chromogenic substrate at 4.4-8.2 lM. They do not significantly inhibit plasma kallikrein, factor (F) XIIa, FXIa, FIXa, FVIIa-TF, FXa, plasmin or cathepsin G. One form, FM19 [rOicPaF(p-Me)], blocks athrombin-induced calcium flux in fibroblasts with an IC 50 of 6.9 ± 1.2 lM. FM19 achieved 100% inhibition of threshold aor c-thrombin-induced platelet aggregation at 8.4 ± 4.7 lM and 16 ± 4 lM, respectively. The crystal structure of thrombin in complex with FM19 shows that the N-terminal D-Arg retrobinds into the S1 pocket, its second residue Oic interacts with His-57, Tyr-60a and Trp-60d, and its C-terminal p-methyl Phe engages thrombinÕs aryl binding site composed of . When administered intraperitoneal, intraduodenal, or orally to mice, FM19 prolongs thrombin clotting times and delays carotid artery thrombosis. Conclusion: FM19, a low affinity reversible direct thrombin inhibitor, might be useful as an add-on agent to address an unmet need in platelet inhibition in acute coronary syndromes in diabetics and others who with all current antiplatelet therapy still have reactive platelets.

Inhibitors of the activation of platelet aggregation have promise as important therapeutic agents for the management of acute coronary syndrome (ACS). Platelet activation by thrombin, a serine protease, occurs by binding to and cleavage of the extracellular N‐terminal domains of protease‐activated receptors 1 and 4 (PAR1 and PAR4). The proteolysis of the PARs exposes new tethered ligands that then signal through transmembrane domains to initiate platelet activation as a downstream effect. A pentapeptide cleavage product of bradykinin with the sequence Arg‐Pro‐Pro‐Gly‐Phe serves as a thrombin inhibitor by blocking α‐ and γ‐thrombin‐induced platelet aggregation. Analogs of RPPGF have been prepared that result in improved inhibition of thrombin activation of platelets. Specific amino acid residues required for activity against platelet aggregation have been identified, and a lead compound, rOicPaPhe(p‐Me)‐NH2 (FM19), has been developed. FM19, which completely inhibits threshold γ‐thrombin‐induced platelet aggregation at a concentration of 16 ± 4 μm, represents an important lead compound in the development of inhibitors of thrombin‐mediated platelet aggregation for treatment of ACS.