This version is available at https://strathprints.strath.ac.uk/10987/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the Strathprints administrator: strathprints@strath.ac.ukThe Strathprints institutional repository (https://strathprints.strath.ac.uk) is a digital archive of University of Strathclyde research outputs. It has been developed to disseminate open access research outputs, expose data about those outputs, and enable the management and persistent access to Strathclyde's intellectual output. Abstract: The predictions of the crystal structure of 3-azabicyclo[3.3.1]nonane-2,4-dione submitted in the 2001 international blind test of crystal structure prediction (CSP2001) led to the conclusion that crystal structures containing an alternative hydrogen bonded dimer motif were energetically competitive with the known catemer-based structure. Here we report an extensive search for a dimer-based crystal structure. Search for a Predicted Hydrogen Bonding MotifUsing an automated polymorph screen a new catemer-based metastable polymorph (form 2) and two new catemer-based solvates were found, and concurrent thermal studies reproduced form 2 and identified a plastic phase (form 3), whose powder X-ray diffraction pattern was consistent with the cubic space group I23 (a ) 7.5856(1) Å). Computational studies on the monomer showed that the imide N-H was a weak hydrogen bond donor, rationalizing the occurrence of the plastic phase which involved the breaking of all hydrogen bonds, and modeling of small clusters showed that dimers could easily reorganize to give the catemer. FTIR spectra confirmed the weakness of the hydrogen bond, with the solute showing no selfassembly in solution. It is concluded that the weakness of the N-H donor, coupled with the globular shape of the molecule, allows unusually facile transformation between alternative hydrogen bonding motifs during aggregation and nucleation.

Laccase, purified from Coriolus versicolor, removed pentachlorophenol (PCP) from solution at pH 5, depending on initial PCP concentration and amount of laccase. With 100 units of laccase, 100% of 25 microg ml(-1) PCP and 60% of 200 microg ml(-1) PCP were removed respectively over 72 h. No free chloride was released in the reaction. In reaction with 100 microg PCP, products were primarily polymers (about 80,000 MW) with only 2-3 pg of o- and p-chloranils formed. Polymers were stable to acid hydrolysis and no release of PCP, or other low-molecular-weight products, was detected over several weeks. Laccase has a potential use in the biotreatment of aqueous effluents containing PCP, with polymerised products being removed from solution due to their high molecular weight.

Cytenamide form I (R) undergoes a solid-state transformation upon heating to form II (P), with the structures exhibiting the same two-dimensional similarity that exists between the R and P forms of carbamazepine

1. A brief introduction to the concept of alkylation is given, which discusses reaction mechanisms and reactivity, and includes an assessment of the susceptibility to alkylation of biologically-important molecules. 2.A semi-quantitative colour test for alkylating agents, with 4-(pnitrobenzyl) pyridine (NBP), has been modified to give a quantitative method for the determination of second-order rate constants, k,, for reaction at 37.5". These constants have been determined for dichlorvos, several other organophosphorus insecticides, and, for comparison, some known biological alkylating agents. 3.These results are discussed in relation to the extensive literature data pertaining to the chemical and biological reactivity of these compounds, and an assessment of the biological importance of the alkylating properties of dichlorvos and related organophosphorus insecticides has been made.4. Since dichlorvos is rapidly metabolized in mammals by esterases present at high activity in the liver and moderate activity in lung, spleen, kidney and blood plasma, the chances of its manifesting spontaneous deleterious biological alkylating activity are very low, and may even be zero. Structure/activity correlations suggest that this will also apply to other organophosphate insecticides, but not necessarily to simple alkyl phosphates such as trimethyl phosphate. Recently Lofroth, Kim & Hussain (1969) have made a preliminary in nitro evaluation of the alkylating properties of dichlorvos (2,2-dichlorovinyl dimethyl phosphate, DDVP), which has prompted them to draw comparisons between dichlorvos and the powerful alkylating agents and known mutagenic agents, methyl and ethyl methanesulphonates.Recently, too, the alkylating properties of some other organophosphorus insecticides have been demonstrated by subjecting them to the NBP (4-(p-nitrobenzy1)pyridine) colour test for alkylating agents (Preussmann, Schneider & Epple, 1969). Strong positive ( + + + ) responses, it was claimed, were given by methylparathion, Chlorthion, Metasystox, thiometon, malathion, Dipterex and Gusathion, and weak positive ( + + ) responses by parathion, ethion, sulfotepp and Systox. Preussmann, et al. (1969) also measured the alkylating properties of about 200 other compounds, including aliphatic and aromatic halogen compounds, lactones and sulphones, epoxides, ethylenimines, diazo and azo compounds, nitrosamines, nitrosamides, and esters of other strong acids. Noteworthy in the latter group were dimethyl sulphate and methyl methanesulphonate, which were given the same (semi-quantitative) top rating of + + + as that given to seven of the organophosphorus insecticides. I n view of this, a critical study of the NBP colour reaction has been made. XB . T Xenobiotica Downloaded from informahealthcare.com by Nyu Medical Center on 07/30/15 For personal use only.T h e first section of this review provides a brief introduction to the concept of alkylation. This is followed by an appraisal of the relevance of the results of the NBP colour test as an index of biological al...

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SummaryInterpretation of the chemical and spectral (IR., UV., lH-and I3C-NMR.) properties of the antitumor antibiotic hedamycin (C41H50N2011) suggests that the molecule contains a methyl substituted 1 -hydroxyanthraquinone nucleus, an a, ,&unsaturated ketone, two sugar-like tetrahydropyran rings (4 and 8) and an aliphatic chain 2, presumably with an epoxy group (see the Scheme).