RESUMEN
The crystal structures of 4-nitro-9,10-dihydrophenanthrene, C14H11NO2, (I), and 4-nitrophenanthrene, C14H9NO2, (II), the latter having two crystallographically independent molecules, show that the molecules are not planar. The dihedral angles between the phenyl rings of the biphenyl skeletons are 28.64 (8) degrees for (I), and 10.34 (15) and 11.75 (13) degrees for the two molecules of (II). The differences in the dihedral angles have an effect on the photochemical reactivity of the molecules.
RESUMEN
The H atoms bonded to the chiral C atoms (stereogenic center) of the 1-cyanoethyl groups in two cobalt complexes, [(R)-1-cyanoethyl]bis(dimethylglyoximato)(pyridine)cobalt(III) (2) and [(R,S)-1-cyanoethyl]bis(dimethylglyoximato)(piperidine)cobalt(III) (3), were replaced with D atoms, such as Co--C*D(CH(3))CN. The crystals of the two cobalt complexes were irradiated with a xenon lamp for 72 h and 27 d, respectively. The unit-cell dimensions were gradually changed with retention of the single-crystal form. The crystal structures after irradiation were determined by neutron diffraction. In each crystal the chiral 1-cyanoethyl group of one of the two crystallographically independent molecules was partly inverted to the opposite configuration, whereas that of the other molecule kept the original configuration. The C*--D bond in the inverted group was completely conserved in the process of the inversion of the chiral alkyl group. This suggests that the inversion of the chiral 1-cyanoethyl group proceeds with the rotation of the cyanoethyl radical after the Co--C bond cleavage by photo-irradiation so that the opposite side of the radical faces the Co atom. This is followed by recombination of the Co--C bond to form the inverted 1-cyanoethyl group.
RESUMEN
The crystal structures of two styrene analogues, 4-vinylbenzoic acid, C(9)H(8)O(2), (I), and 9-vinylanthracene, C(16)H(12), (II), were determined by X-ray analyses at 108 and 293 K for (I) and at 123 and 293 K for (II). In (I), a pair of molecules around an inversion center form a dimer connected by two carboxyl groups. The anthracene planes of two molecules in (II) are antiparallel to each other around an inversion center. The vinyl group of (I) is almost coplanar with the phenyl ring, whereas the vinyl group of (II) is nearly perpendicular to the anthracene plane. In (I), the bond length of the vinyl group at 293 K is significantly shorter than that at 108 K [1.288 (2) versus 1.3248 (14) A] suggesting a bias of the thermal motion, whereas the bond lengths are not so different between the two temperatures in (II) [1.3266 (15) versus 1.310 (2) A].
RESUMEN
Glucuronides of RT-3003 and its metabolite (9-OH-RT-3003), which was hydroxylated at the 9 position on the benzene ring, were separated by HPLC and identified by liquid chromatography (LC)/MS/MS and NMR. The conjugation sites of these glucuronides were determined by nuclear Overhauser effects (NOE) irradiation; RT-3003 was conjugated at an alcoholic hydroxyl group of the hydroxymethyl moiety, and 9-OH-RT-3003 at a phenolic hydroxyl group on a benzene ring and at an alcoholic hydroxyl group of a hydroxymethyl moiety. On a reversed-phase HPLC of 9-OH-RT-3003, alcoholic glucuronide was eluted later than phenolic glucuronide, indicating the high hydrophobicity of alcoholic glucuronide. Clearance for the glucuronidation (ClG) of RT-3003 was lower than the summation of ClG for two types of glucuronidation of 9-OH-RT-3003. ClG of 9-OH-RT-3003 was high in phenolic glucuronide. The activity of UDP-glucuronyltransferase (UDPGT) for RT-3003 was 9.63 times that for 9-OH-RT-3003, and the activity ratio of the two types of glucuronidation of 9-OH-RT-3003 was similar to the ratio of the corresponding ClG. The difference between ClG and UDPGT activity is discussed in association with clearance for the hydroxylation and interaction of substrates with UDPGT.