@article {2658, title = {Composition of secondary alcohols, ketones, alkanediols, and ketols in Arabidopsis thaliana cuticular waxes}, journal = {Journal of Experimental Botany}, volume = {60}, number = {6}, year = {2009}, note = {ISI Document Delivery No.: 437ZCTimes Cited: 0Cited Reference Count: 25Wen, Miao Jetter, Reinhard}, month = {Apr}, pages = {1811-1821}, type = {Article}, abstract = {Arabidopsis wax components containing secondary functional groups were examined (i) to test the biosynthetic relationship between secondary alcohols and ketols and (ii) to determine the regiospecificity and substrate preference of the enzyme involved in ketol biosynthesis. The stem wax of Arabidopsis wild type contained homologous series of C-27 to C-31 secondary alcohols (2.4 mu g cm(-2)) and C-28 to C-30 ketones (6.0 mu g cm(-2)) dominated by C-29 homologues. In addition, compound classes containing two secondary functional groups were identified as C-29 diols (similar to 0.05 mu g cm(-2)) and ketols (similar to 0.16 mu g cm(-2)). All four compound classes showed characteristic isomer distributions, with functional groups located between C-14 and C-16. In the mah1 mutant stem wax, diols and ketols could not be detected, while the amounts of secondary alcohols and ketones were drastically reduced. In two MAH1-overexpressing lines, equal amounts of C-29 and C-31 secondary alcohols were detected. Based on the comparison of homologue and isomer compositions between the different genotypes, it can be concluded that biosynthetic pathways lead from alkanes to secondary alcohols, and via ketones or diols to ketols. It seems plausible that MAH1 is the hydroxylase enzyme involved in all these conversions in Arabidopsis thaliana.}, keywords = {BRASSICA-OLERACEA, chain lengths, CHROMATOGRAPHY, cytochrome P450, ECERIFERUM MUTANTS, EPICUTICULAR WAXES, fatty acid derivatives, GAS, HYDROXYLATION, LEAF WAXES, LEAVES, MAH1, MASS SPECTROMETRY, neutral lipids, plant surface composition, RESISTANT, ULTRASTRUCTURE, wax}, isbn = {0022-0957}, url = {://000265524400023}, author = {Wen, M. and Jetter, R.} } @article {754, title = {Synthesis and characterization of beta-trifluoromethyl-meso-tetraphenylporphyrins}, journal = {Journal of Organic Chemistry}, volume = {68}, number = {5}, year = {2003}, note = {ISI Document Delivery No.: 651PVTimes Cited: 18Cited Reference Count: 59}, month = {Mar}, pages = {1892-1900}, type = {Article}, abstract = {beta-Trifluoromethyl-meso-tetraphenylporphyrins were synthesized to investigate the electronic and steric effects of the trifluoromethyl groups on the macrocycle. Preparation of these novel porphyrins was carried out by copper-assisted trifluoromethylation of beta-tetrabromo-meso-tetraphenylporphyrin metal complexes and in situ generated CF3Cu. For comparison, the beta-methyl analogues were also prepared. Analysis of beta-trifluoromethylporphyrins by UV-vis, NMR, and cyclic voltammetry (CV) showed that the electron-withdrawing effects of the trifluoromethyl groups on the antipodal pyrroles required the macrocycle to take a fixed 18pi-electron pathway. UV-vis, CV, and molecular modeling studies suggest that the novel porphyrins are distorted following introduction of trifluoromethyl groups onto the pyrrolic beta-position of meso-tetraphenylporphyrin. The pK(a) difference of beta-tetrakis(trifluoromethyl)-meso-tetraphenylporphyrin from that of DBU in CH2Cl2, obtained by spectrophotometric titration, affirms that it is one of the most electron-deficient porphyrins so far prepared.}, keywords = {BROMINATED-PYRROLE TETRAPHENYLPORPHYRIN, COMPLEXES, EFFICIENT CATALYSTS, ELECTROCHEMISTRY, ELECTRON-DEFICIENT PORPHYRINS, HYDROXYLATION, METALLOPORPHYRINS, REDOX POTENTIALS, SUBSTITUENTS, X VARIES}, isbn = {0022-3263}, url = {://000181329900033}, author = {Terazono, Y. and Dolphin, D.} } @article {4566, title = {The biomimetic oxidation of dieldrin using polyhalogenated metalloporphyrins}, journal = {Chemical Communications}, number = {7}, year = {1999}, note = {ISI Document Delivery No.: 184WETimes Cited: 7Cited Reference Count: 16}, month = {Apr}, pages = {629-630}, type = {Article}, abstract = {Biomimetic oxidation of dieldrin produces the same metabolites as generated in vivo, which suggest a {\textquoteright}radical oxygen-rebound{\textquoteright} mechanism.}, keywords = {HYDROXYLATION, iron}, isbn = {1359-7345}, url = {://000079636100030}, author = {Hino, F. and Dolphin, D.} } @article {4304, title = {Oxidation of 2-methylpyrroles with perchlorinated iron(III) metalloporphyrin catalysts: a versatile synthesis of symmetric and asymmetric dipyrromethanes}, journal = {Canadian Journal of Chemistry-Revue Canadienne De Chimie}, volume = {76}, number = {10}, year = {1998}, note = {ISI Document Delivery No.: 156LMTimes Cited: 0Cited Reference Count: 22}, month = {Oct}, pages = {1467-1473}, type = {Article}, abstract = {A variety of substituted 2-methylpyrroles (3-8) were oxidized using the metalloporphyrin catalysts iron(III) meso-tetra(2, 6-dichloro-3-sulphonatophenyl)-beta-octachloroporphyrin chloride 1 and iron(III) meso-tetra(2,6-dichlorophenyl)-beta-octachloroporphyrin chloride 2 under very mild conditions. Treatment of the resulting allylic alcohols 3a-8a with alpha-free pyrroles 9 and 10 resulted in a very efficient synthesis of the corresponding dipyrromethanes 3b-8b and 3c-8c. Furthermore, the above allylic alcohols when treated with furfurylamine produced the novel (2-furylmethyl)-2-pyrrolylmethylamines 3d-8d.}, keywords = {catalytic oxidation, dipyrromethanes, EPOXIDATIONS, HYDROXYLATION, iodosylbenzene, METALLOPORPHYRINS, polyhalogenated porphyrins, PYRROLES, TETRAPHENYLPORPHYRINS}, isbn = {0008-4042}, url = {://000078002800017}, author = {Karunaratne, V. and Dolphin, D.} } @article {3944, title = {Polyhaloporphyrins: Unusual ligands for metals and metal-catalyzed oxidations}, journal = {Accounts of Chemical Research}, volume = {30}, number = {6}, year = {1997}, note = {ISI Document Delivery No.: XE058Times Cited: 283Cited Reference Count: 63}, month = {Jun}, pages = {251-259}, type = {Review}, keywords = {halogenated porphyrins, HYDROGEN-PEROXIDE, HYDROXYLATION, Iron(III), IRON-PORPHYRIN COMPLEXES, manganese porphyrins, METALLOPORPHYRINS, MODEL SYSTEMS, porphyrins, SATURATED-HYDROCARBONS, TERT-BUTYL HYDROPEROXIDE}, isbn = {0001-4842}, url = {://A1997XE05800004}, author = {Dolphin, D. and Traylor, T. G. and Xie, L. Y.} } @article {3777, title = {A biomimetic study of cytochrome P450 related oxidations of toluenes using synthetic hemin}, journal = {Bulletin of the Chemical Society of Japan}, volume = {69}, number = {12}, year = {1996}, note = {ISI Document Delivery No.: WB844Times Cited: 6Cited Reference Count: 68}, month = {Dec}, pages = {3513-3521}, type = {Article}, abstract = {A mechanistic study of the oxidation of toluene and its derivatives in a model system designed to mimic cytochrome P450 (P450) using iron tetrakis(2,6-dichlorophenyl)porphyrin chloride (FeTPPC8Cl) and pentafluoroiodosylbenzene (PFIB:C(6)F(5)lO) in dichloromethane is reported. The oxidation products were the corresponding benzyl alcohols and aldehydes; no further oxidation products were observed. The relative reaction rates were obtained in competitive reactions including the use of deuterated analogues. In the present model system, Hammett plots and isotope effects indicated conclusively that the rate-determining step was a hydrogen atom abstraction to the oxoiron intermediate which was then followed by a rebound of an OH group. The concerted mechanism and the rebound mechanism were discussed in terms of the differences in reactivities between the model system and natural P450 enzymes and similar monooxygenation enzymes.}, keywords = {ALIPHATIC, AROMATIC-COMPOUNDS, CRYSTAL-STRUCTURE, DEPENDENT MONO-OXYGENASES, HYDROGEN-PEROXIDE, HYDROXYLATION, INDUCED, IRON(III) PORPHYRINS, LIVER MICROSOMAL CYTOCHROME-P-450, METABOLISM, MODEL SYSTEMS, RAT-LIVER}, isbn = {0009-2673}, url = {://A1996WB84400017}, author = {Nakano, T. and Agatsuma, N. and Kodama, S. and Kakuda, H. and Dolphin, D.} } @article {3633, title = {Improved protocols for the synthesis and halogenation of sterically hindered metalloporphyrins}, journal = {Synthesis-Stuttgart}, number = {11}, year = {1996}, note = {ISI Document Delivery No.: VV383Times Cited: 31Cited Reference Count: 38}, month = {Nov}, pages = {1320-\&}, type = {Article}, abstract = {Improved procedures are described for the synthesis of meso-tetrakis(2,6-dichlorophenyl)porphyrin and for subsequent perhalogenation of the porphyrin ring.}, keywords = {ACCESS, CATALYSTS, CATALYTIC OXYGENATION, EASY, EFFICIENT CATALYSTS, EPOXIDATION, halogenated porphyrins, HYDROXYLATION, metalloporphyrins halogenation, OXIDATION, OXIDATION REACTIONS, porphyrins, TETRAARYLPORPHYRINS, TETRAMESITYLPORPHYRIN, TETRAPHENYLPORPHYRINS}, isbn = {0039-7881}, url = {://A1996VV38300016}, author = {Chorghade, M. S. and Dolphin, D. and Dupre, D. and Hill, D. R. and Lee, E. C. and Wijesekera, T. P.} } @article {3754, title = {Stereoselective synthesis of new chlorophyll A related antioxidants isolated from marine organisms}, journal = {Journal of Organic Chemistry}, volume = {61}, number = {7}, year = {1996}, note = {ISI Document Delivery No.: UD653Times Cited: 39Cited Reference Count: 37}, month = {Apr}, pages = {2501-2510}, type = {Article}, abstract = {A new class of natural antioxidants, chlorophyll a related chlorins 3, 4(S), 4(R), 5(R), 6, 7, 8, and 9, have been synthesized from a chlorophyll a degradation product, pheophorbide a methyl ester (1). Claisen-type intramolecular condensation of pyropheophorbide a methyl ester (2) afforded the common intermediate enol 3. Chlorin 1 and enol 3 have a propensity to undergo exocyclic ring opening by ionic bases. The organic base DBU was found to be an efficient reagent for promoting the asymmetric hydroxylation of these chlorins, using N-sulfonyloxaziridines, without cleavage of the exocyclic rings. Model studies for hydroxylactonization have shown that periodate oxidation of hydroxy ketone 10 stereoselectively and predominantly forms hydroxy lactone 17(S). Periodate oxidation of alpha-hydroxy 1,3-diketone 4(R) and/or 4(S) to furnish hydroxy lactone 5(R) and diketone 7 was found out to be regioselective, and the site of reaction depends on the appropriate choice of reaction media. H-1 NMR spectra have provided information on the absolute configuration of diastereomers at the C-13(2) or C-15(1) position.}, keywords = {2-SULFONYLOXAZIRIDINES, CHEMISTRY, COMPOUND, DERIVATIVES, enol, HYDROXYLATION, ORIGINS, RCI, RUDITAPES-PHILIPPINARUM}, isbn = {0022-3263}, url = {://A1996UD65300039}, author = {Ma, L. F. and Dolphin, D.} }