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Biomedical subjects

R E Marsh

Publications and source records attributed to R E Marsh.

17 recordsLinked to original sources
PubMed1992

A chiral N-crotonyloxazolidinone Diels-Alder adduct.

(4S)-4-Benzyl-3-[(4S,5S)-(1-methoxy-5-methylcyclohexen-4- yl)carbonyl]-2-oxazolidinone, C19H23NO4, M(r) = 329.40, monoclinic, P2(1), a = 11.453 (3), b = 7.163 (4), c = 11.929 (2) A, beta = 111.86 (2) degree, V = 908.3 (5) A3, Z = 2, D chi = 1.20 g cm-3, lambda (Mo K alpha) = 0.71073 A, mu = 0.79 cm-1, F(000) = 352, T = 297 K, R = 0.034 for 885 reflections with Fo2 greater than 0. The molecule is extended in the crystal; there is a small twist, -13.1 (2) degree, about the amide-like C--N bond joining the oxazolidinone ring to the carbonyl group. The configurations at the two optical centers in the cyclohexene ring confirm the anticipated stereospecificity of the Diels-Alder cycloaddition synthesis.

Benzyl Compounds↗
PubMed1988

Structure of C32H34N2O5S2: corrigendum.

The structure of this compound [Olszak, Stepień, Wajsman, Grabowski, Glinka & Lecocq (1987). Acta Cryst. C43, 2169-2171], which contains a 13-membered heterocyclic ring, was described as triclinic, space group P1, with a = 12.756 (3), b = 9.950 (3), c = 13.566 (3) A, alpha = 90.49 (1), beta = 118.04 (1), gamma = 90.04 (1) degrees, Z = 2. It should be described as monoclinic, space group C2/c, with a' = 23.947 (6), b' = 12.756 (3), c' = 9.950 (3) A, beta' = 90.57 (3) degrees, Z = 4. The C2/c coordinates are given. The molecule lies on an exact, rather than an approximate, twofold axis.

Crystallography↗
PubMed1988

The structure of Te(OH)6.Na3P3O9.K3P3O9.

The structure of this compound, originally described in space group C2/c [Averbuch-Pouchot & Durif (1987). Acta Cryst. C43, 1653-1655] is properly described as rhombohedral, space group R3c, with a = 12.355 (4) A, a = 51.01 (2) degrees, Z = 2. (Hexagonal cell: a = 10.640 (4), c = 32.16 (2) A, Z = 6). Revised coordinates are given.

Crystallography↗
PubMed1988

More space-group changes.

Revised structures are reported for 19 crystalline compounds, based on space groups of higher symmetry than originally reported. In four cases the Laue symmetry is changed, one from 1 to 2/m and three from 2/m to mmm; in the remaining fifteen a center of symmetry has been added. For eight of these latter compounds we have obtained F values and carried out least-squares refinements in the centrosymmetric space groups, with more satisfactory results than originally reported.

Crystallography↗
PubMed1973

Prospects of chemosterilant and genetic control of rodents.

This paper discusses some requirements of an ideal rodent chemosterilant, analyses the advantages of chemosterilants over other control methods, and compares the potential values of chemosterilants that affect females, males, and both sexes. Examples are given of specific situations where chemosterilants will be valuable in rodent control, together with suggested methods of applying them. The theory and practicability of using genetics in rodent control are also discussed. Neither the chemosterilant nor the genetic method is expected to become a panacea, but their eventual application will be a significant advance in rodent-control technology. Since both approaches are based on sound biological principles and are relatively safe, they should be helpful in regulating rodent populations in the future.

Animals↗
PubMedDate not supplied

Fluoroacetate residues in ground squirrel and coyote tissues due to primary or secondary 1080 poisoning.

Fluoroacetate residues in various tissues of 1080-poisoned ground squirrels and coyotes are listed. The tissues (excluding the stomach) of squirrels poisoned with an average of 0.8 mg 1080/kg (low dose) contained from 182 to 1309 ppb fluoroacetate. In squirrels poisoned with an average of 4.8 mg 1080/kg (high dose), the tissue residues ranged from 535 to 9754 ppb fluoroacetate. Tissues from coyotes which died after consuming 1080-poisoned ground squirrels were also analyzed for fluoroacetate residues. Residues in these coyote kidneys and livers ranged from less than 10 ppb to 95 ppb fluoroacetate. The residue findings in this research indicate that a diagnostic assay for 1080 in tissues must be reliable at 10 ppb (or less) fluoroacetate.

Animals↗