Determination and mass spectrometric investigation of a new mixed halogenated persistent component in fish and seal.

An unknown component that caused an intense signal in sample extracts of fish tissue was enriched and investigated using a variety of mass spectrometric techniques coupled to gas chromatographic separation. With the help of electron capture negative ion mass spectrometry (ECNI-MS) and electron impact mass spectrometry (EI-MS) it was established that the component carries 2Br and 3Cl atoms and forms a molecular ion at m/z 396. A concentrated solution of this mixed halogenated compound (MHC-1) was investigated by gas chromatography interfaced to electron impact high-resolution mass spectrometry (GC/EI-HRMS). Using full scan and SIM techniques, the molecular formula of MHC-1 was established to be C10H13Br2Cl3. This points toward MHC-1 having a monoterpene backbone. No chemical with this molecular formula has been synthesized, but two components with this composition have been earlier isolated from marine algae.

Large-scale synthesis of hematoregulatory nonapeptide SK&F 107647 by fragment coupling.

Linear and convergent routes for the large-scale preparation of the hematoregulatory nonapeptide (Glp-Glu-Asp)2-DAS-(Lys)2 (2, SK&F 107647) were investigated. A convergent approach ('3 + 2'-route employing Boc-and benzyl ester protecting groups) was selected for the preparation of multihundred-gram quantities of 2. Key steps were the preparation and the coupling of tripeptide hydrochloride (HCl.H)2-DAS-(Lys(Z)-OBn)2 (6, DAS-2,7-L,L-diaminosuberic acid) and tripeptide Glp-Glu(OBn)-Asp(OBn)-OH (26). Several coupling reagents were investigated in order to reduce the amount of epimerization of this fragment coupling. TDBTU [O-(3,4-dihydro-4-oxo-1,2,3-benzotriazin-3-yl-1,1,3,3-tetrameth yluronium tetrafluoroborate] was identified as the condensation reagent of choice. Using this synthetic route > 97% pure final product in an overall yield of 35% calculated on di-Boc protected 2,7-L,L-diaminosuberic acid was prepared.

Structure-activity relationships of novel hematoregulatory peptides.

Hematopoiesis is a lifelong cell renewal process regulated by a family of lineage specific hematopoietic growth factors. Several hematopoietic growth factors such as G-CSF, GM-CSF, and M-CSF have been clinically evaluated for enhancement of host defense in normal and immunocompromised patients and for the treatment of infectious diseases. This paper reports the structure-activity relationships of low molecular weight hematoregulatory peptides based on a nonapeptide (1, SK&F 107647). Like the macromolecular growth factors, these peptides modulate host defense. A molecular target for this class of compounds has not yet been identified. However, the structure-activity relationships established by this study implicate a very specific molecular recognition event that is pivotal for the biological activities of 1 and its analogues.

Side-chain derivatives of biologically active nucleosides. 1. Side-chain analogs of 3'-azido-3'-deoxythymidine (AZT).

Starting from 3-O-mesyl-1,2-O-isopropylidene-alpha-D-allofuranose (9) the anomeric mixtures of the requisite carbohydrates 1,2-di-O-acetyl-6-O-benzoyl-5-deoxy-3-O-mesyl-D-allofuranoses++ + 17A alpha/beta, 1,2-di-O-acetyl-5,6-di-O-benzoyl-3-O-mesyl-D-allofuranoses 17B alpha/beta, and 1,2-di-O-acetyl-5,6-di-O-benzoyl-3-O-mesyl-L-talofuranoses 17C alpha/beta were synthesized. 1,2-Di-O-acetyl-5-O-benzoyl-6-deoxy-3-O-mesyl-D-allofuranoses++ + 17D alpha/beta and the corresponding L-talofuranoses 17E alpha/beta were obtained from 6-deoxy-3,5-di-O-benzoyl-1,2-O-isopropylidene-alpha-D- allofuranose (12) and the corresponding beta-L-talofuranose 13. Coupling of these sugar derivatives with thymine gave the beta-nucleoside derivatives 18A-E. Treatment of compounds 18A-E with DBU produced the corresponding 2,3'-anhydro nucleosides 19A-E with a free 2'-OH group. After deoxygenation of 2'-O-[[(4-methylphenyl)oxy]thiocarbonyl] compounds 20A-E with tributyltin hydride the 2,3'-anhydro bridge of the 2'-deoxynucleosides 21A-E was opened with LiN3 to produce the protected 3'-azido-2,3'-dideoxynucleoside derivatives 22A-G. Saponification with NaOCH3 gave 1-(3'-azido-2',3',5'-trideoxy-beta-D-allofuranosyl)thymine (2; homo-AZT), the 5'-C-(hydroxymethyl) derivatives of AZT 1-(3'-azido-2',3'- dideoxy-beta-D-allofuranosyl)thymine (3) and 1-(3'-azido-2',3'-dideoxy-alpha-L-talofuranosyl)thymine (4), and the 5'-C-methyl derivatives of AZT 1-(3'-azido-2',3',6'-trideoxy-beta-D-allofuranosyl)thymine (5) and 1-(3'-azido-2',3',6'-trideoxy-alpha-L-talofuranosyl)thymine (6). Compounds 2-6 were evaluated for their inhibitory effect on human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) replication in MT-4 cells and found inactive at subtoxic concentrations. Compounds 2-4 and 6 are not effective against herpes simplex virus type 1 (HSV-1) and type 2 (HIV-2), vaccinia virus (VV), and vesicular stomatitis virus (VSV) at 400 micrograms/mL. 5 is slightly active against HSV-1, HSV-2 and VV at 150, 300, and 300 micrograms/mL, respectively.

[Results of human milk analysis for pesticide levels in women of the south Bavarian region]. / Ergebnisse von Frauenmilchuntersuchungen aus dem südbayerischen Raum auf Schadstoffgehalte.

During the years 1986 to 1990 1.538 samples of human milk were analyzed by the "Landesuntersuchungsamt für das Gesundheitswesen Südbayern". Here we report on our results with emphasis on organochlorine pesticide and polychlorinated biphenyl analysis. Determination of PCDD and PCDF was possible only in a few samples for technical reasons. In 1984 the "Kommission zur Prüfung von Rückständen in Lebensmitteln" of the Deutsche Forschungsgemeinschaft published so-called tolerable concentrations for some pesticides and PCBs in human milk. These concentrations have been exceeded only in a few samples (HCB, DDT + DDE, PCB). There is a trend of decreasing concentrations in the last years. A good correlation between the concentrations of pesticides and the age of mothers and the number of births could be shown. There are regional differences in the concentrations of HCB. This study shows the persistence of some substances in human milk even years after banning their usage.

Synthesis and antiretrovirus properties of 5'-isocyano-5'-deoxythymidine, 5'-isocyano-2',5'-dideoxyuridine, 3'-azido-5'-isocyano-3',5'-dideoxythymidine, and 3'-azido-5'-isocyano-2',3',5'-trideoxyuridine.

The 5'-azidonucleosides 3 and 4 were obtained by treating thymidine and 2'-deoxyuridine with TPP/DEAD/HN3. The 3'-O-silylated 5'-azido-5'-deoxythymidine 5 and the corresponding 2'-deoxyuridine derivative 6 were transformed to the formamides (7 and 8, respectively) and dehydrated to the protected 5'-isocyano derivatives 9 and 10; deblocking gave 5'-isocyano-5'-deoxythymidine (11) and 5'-isocyano-2',5'-dideoxyuridine (12). 2,3'-Anhydro-5'-formamido derivatives of thymidine and 2'-deoxyuridine (19 and 20, respectively) were prepared by three different ways. In the most direct synthesis 3 and 4 were transformed to the 2,3'-anhydro-5'- azidonucleosides 17 and 18 by using TPP/DEAD; following the reaction with TPP/HCO2COCH3 gave 19 and 20. Nucleophilic opening reaction with LiN3 yielded the 3'-azido-5'-formylamino derivatives 21 and 22. Dehydration to 3'-azido-5'-isocyano-3',5'-dideoxythymidine (23) and 3'-azido-5'-isocyano-2',3',5'-trideoxyuridine (24) was achieved with tosyl chloride/pyridine. In contrast with 3'-azido-3'-deoxythymidine, compounds 11, 12, 23, and 24 were devoid of any marked inhibitory effect against DNA and RNA viruses including human immunodeficiency virus type I (HIV).

Synthesis, antiretrovirus effects, and phosphorylation kinetics of 3'-isocyano-3'-deoxythymidine and 3'-isocyano-2',3'-dideoxyuridine.

The silylated AzddThd 5 and AzddUrd 6 prepared from 2,3'-anhydronucleoside derivatives 3 and 4 were transformed to formamides 7 and 8 by using the sequence RN3----RN = P(C6H5)----RNHCHO. Formamides 7 and 8 were dehydrated to the protected 3'-isocyano derivatives 9 and 10; deblocking gave 11 and 12. Neither 3'-isocyano-3'-deoxythymidine (11) nor 3'-isocyano-2',3'-dideoxyuridine (12) showed anti-HIV activity at noncytotoxic concentrations. ddThd derivative 11 was considerably more toxic to MT-4 cells than ddUrd derivative 12; it also had a much greater affinity (Ki) for MT-4 cell dThd kinase than ddUrd derivative 12. Both compounds appear to be linear mixed-type inhibitors of MT-4 cell dThd kinase.