A European population in Minoan Bronze Age Crete.

The first advanced Bronze Age civilization of Europe was established by the Minoans about 5,000 years before present. Since Sir Arthur Evans exposed the Minoan civic centre of Knossos, archaeologists have speculated on the origin of the founders of the civilization. Evans proposed a North African origin; Cycladic, Balkan, Anatolian and Middle Eastern origins have also been proposed.

7,8-Dihydroxy-4-propyl-1,2,3,4,4a,5,6,10b-octahydrobenzo[f]quinolinium bromide monohydrate, a dopamine agonist.

In the crystal structure of the title dopaminergic compound, C16H24NO2+.Br-.H2O, protonation occurs at the piperidine N atom.

Stereochemical basis for activity in thiadiazole anticonvulsants: 1-[5-(biphenyl-2-yl)-1,3,4-thiadiazol-2-yl]methanaminium chloride and two inactive analogues, 2-(biphenyl-4-yl)-5-[2-(1-methylethylidene)hydrazino]-1,3,4-thiadiazole and the methanol solvate of its hydrochloride salt.

In 1-[5-(biphenyl-2-yl)-1,3,4-thiadiazol-2-yl]methanaminium chloride, C15H14N3S+.Cl-, the protonation occurs at the amine N atom. The outer phenyl ring makes an angle of 88.

2-acetamido-N-benzyl-2-(methoxyamino)acetamides: functionalized amino acid anticonvulsants.

In the crystal structure of 2-acetamido-N-benzyl-2-(methoxyamino)acetamide (3L), C12H17N3O3, the 2-acetylaminoacetamide moiety has a linearly extended conformation, with an interplanar angle between the two amide groups of 157.3 (1) degrees . In 2-acetamido-N-benzyl-2-[methoxy(methyl)amino]acetamide (3N), C13H19N3O3, the planes of the two amide groups intersect at an angle of 126.

Ethyl 5-isopropoxy-4-methyl-beta-carboline-3-carboxylate: structural determinants of benzodiazepine-receptor antagonism.

Molecules of the title compound, C18H20N2O3, are linked into ribbons by N-H...

Two rhodamine derivatives: 9-[2-(ethoxycarbonyl)phenyl]-3,6-bis-(ethylamino)-2,7-dimethylxanthylium chloride monohydrate and 3,6-diamino-9-[2-(methoxycarbonyl)-phenyl]xanthylium chloride trihydrate.

The title compounds, C28H31N2O3(+)-Cl(-)-H2O (common name rhodamine-6g), (I), and C21H17N2O3(+)-Cl(-)-3H2O (common name rhodamine-123), (II), both have planar xanthene skeletons with a formal +1 charge on the amino N atoms delocalized through the pi-electron system so that the N-Csp(2) bond distances indicate significant double-bond character. The substituted planar phenyl groups make angles of 63.29 (8) and 87.

Crystal structure of the hydrated strontium salt of methotrexate: two independent molecules with different conformations.

The crystal and molecular structure of methotrexate has been determined by X-ray diffraction from a highly hydrated triclinic crystal form in which the asymmetric unit contains two independent methotrexate molecules with their glutamate carboxyl groups coordinated to two strontium ions. The two methotrexates exhibit differing conformations: They are almost related to one another by a pseudocenter of symmetry. This places the C(9)-N(10) bond vectors on opposite sides of the planes of the pteridine rings.

The antifolate trimetrexate: observation of the enzyme-binding conformation.

The crystal structure of the title compound contains four 2, 4-diamino-5-methyl-6-[(3,4,5-trimethoxyanilino)methyl]quinazoline molecules, two dimethyl sulfoxide molecules and three water molecules in the asymmetric unit, i.e. 4C(19)H(23)N(5)O(3).

Ranitidine hydrochloride, a polymorphic crystal form.

In the title compound, dimethyl(¿5-[2-(1-methylamino-2-nitroethenylamino)ethylthiometh yl]-2- furyl¿methyl)ammonium chloride, C(13)H(23)N(4)O(3)S(+).Cl(-), protonation occurs at the dimethylamino N atom. The ranitidine molecule adopts an eclipsed conformation.

Bis(2,2-dimethylaziridinyl)phosphinic amide.

The asymmetric unit of the title compound, C8H18N3OP, contains one bis(2,2-dimethylaziridinyl)phosphinic amide molecule. The crystal structure is characterized by hydrogen bonds from the amide-N atom, which involve both H atoms of the amino group, to the phosphinic-O atom in two different molecules, thus forming infinite double-stranded chains along the base vector [100], and by hydrophobic contacts between these chains.

A Schiff base formed from sulfanilic acid and dimethylformamide.

The crystal structure the Schiff base contains one 4-dimethylaminomethyleneaminobenzenesulfonic acid molecule in zwitterionic form [4-(dimethylaminomethyleneammonio)benzenesulfonate], and one water molecule in the asymmetric unit (C9H12N2O3S.H2O). Protonation occurs at nitrogen atom N1, but the charge is delocalized.

FF-beta-D-arabinofuranosyluracil.

In the title compound, 1-(2-deoxy-2-fluoro-beta-D-arabino-furanosyl)-5-fluoropyrimidine-2, 4(1H,3H)-dione, C9H10-F2N2O5, the furanosyl ring adopts the twisted conformation (T) with O1' endo and C1' exo. The crystal structure is characterized by a three-dimensional hydrogen-bond network involving the three H atoms bonded to heteroatoms.

Crystal and molecular structure of paclitaxel (taxol).

Paclitaxel (formerly called taxol), an important anticancer drug, inhibits cell replication by binding to and stabilizing microtubule polymers. As drug-receptor interactions are governed by the three-dimensional stereochemistries of both participants, we have determined the crystal structure of paclitaxel to identify its conformational preferences that may be related to biological activity. The monoclinic crystals contain two independent paclitaxel molecules in the asymmetric unit plus several water and dioxane solvent molecules.

Glucosidase inhibitors: structures of deoxynojirimycin and castanospermine.

High-resolution structures of the glucosidase inhibitors deoxynojirimycin (dNM) and castanospermine (CAST) have been determined by X-ray diffraction. The crystal parameters are a = 10.751(3) and 8.

Structure of the anti-human immunodeficiency virus agent 3'-fluoro-3'-deoxythymidine and electronic charge calculations for 3'-deoxythymidines.

The crystal and molecular structures of the anti-human immunodeficiency virus agent 3'-fluoro-3'-deoxythymidine have been determined by x-ray diffraction and stereochemical comparisons with thymidine have been made. Atomic charge distributions have been calculated by the complete neglect of differential overlap method for thymidine and antiretrovirally active and inactive C3'-substituted analogues. The structural and electronic results suggest that antiviral activity in these analogues may be correlated with the presence of an electronegative atom attached to C3'.

Azidothymidine: crystal structure and possible functional role of the azido group.

The crystal and molecular structures of the anti-acquired immunodeficiency syndrome agent 3'-azido-3'-deoxythymidine (AZT) have been determined by x-ray diffraction. There are two crystallographically independent AZT molecules in the crystal asymmetric unit; they have similar conformations and differ primarily in the glycosyl torsion angle. Comparisons with a hydrated thymidylate structure indicate that the azido group does not significantly affect the gross conformational preference of the molecule.

Crystal structure of an extended-conformation leucine-enkephalin dimer monohydrate.

The structure of a new crystal form of leucine-enkephalin has been determined by X-ray diffraction. There are two independent molecules in the asymmetric unit and both have extended peptide backbone conformations with side-chains arranged alternately above and below the backbone planes. The two pentapeptides are hydrogen-bonded to each other and to other molecules forming an extended antiparallel beta-pleated sheet.

Crystal structure of methionine-enkephalin.

The crystal structure of methionine-enkephalin has been determined by X-ray crystallography. There are two independent pentapeptides in the asymmetric unit and both display extended backbone conformations with their side chains arranged alternately below and above the backbone plane. The two molecules form a hydrogen-bonded head-to-tail dimer similar in conformation to one dimeric pair of leucine-enkephalin molecules in a previously reported crystal structure.

Crystal structure of quinespar, a quinazoline analogue of methotrexate.

The molecular structure of quinespar, a quinazoline analogue of methotrexate and aminopterin, has been determined by X-ray crystallography. The molecule displays an extended conformation with the p-aminobenzoyl plane rotated 66 degrees from the plane of the quinazoline. The orientation of the quinazoline ring relative to the rest of the molecule is intermediate between the orientations of the comparable pteridine rings in folic acid and in DHFR-bound methotrexate.

Crystal structure of leucine-enkephalin.

The crystal structure of leucine-enkephalin has been determined in a crystal form that has four independent enkephalin molecules and much water and dimethylformamide solvent in the asymmetric unit. All four enkephalins have extended peptide backbones with the Tyr, Phe and Leu side chains above and below the plane of the backbone. There is evidence that this extended conformation may provide an acceptable model for enkephalin binding to opiate mu-receptors.

Hydrogen bonding interaction of diphenylhydantoin and 9-ethyladenine.

A hydrogen-bonded complex of diphenylhydantoin (DPH) and 9-ethyladenine (EtAd) crystallizes from 2,4-pentanedione with the asymmetrical unit consisting of two DPH molecules, one EtAd molecule, and one solvent molecule. The crystal structure was solved by direct methods and refined to a residual of R = 0.054.

Folic acid: crystal structure and implications for enzyme binding.

The crystal and molecular structure of folic acid dihydrate has been determined by x-ray diffraction. Folic acid is in an extended conformation with the pteridine ring in the keto form. The C(4) oxygen and N(10) atoms are on the same side of the molecule, hydrogen-bonded to the same water.