William T. A. Harrison

Learn More
The two naphthopyrones 6-methoxycomaparvin (1) and 6-methoxycomaparvin 5-methyl ether (2) were isolated from a bioactive methanol-soluble extract of the Fijian echinoderm Comanthus parvicirrus. Their structures were assigned on the basis of spectroscopic methods. X-ray diffraction analysis was used to confirm the structure of 1. Both compounds were tested(More)
The metabolic profile of Streptomyces sp. strain C34, isolated from the Chilean hyper-arid Atacama Desert soil, is dependent on the culture media used for its growth. The application of an OSMAC approach on this strain using a range of cultivation media resulted in the isolation and identification of three new compounds from the rare class of 22-membered(More)
Three new compounds of the rare classes trisnorditerpenes, bisnorditerpenes, and norditerpenes, gracilins J-L (1, 2, 6), and a new diterpene, 3'-norspongiolactone (8), were isolated from the extract of the marine sponge Spongionella sp. using NMR- and bioassay-guided fractionation, in addition to three known gracilins (3-5) as well as the known diterpenoid(More)
The structure of the title natural product, 1',5-dihydroxy-3',7-dimethyl-2,2'-binaphthalene-1,4,5',8'-tetrone, C(22)H(14)O(6), confirms the atomic connectivity postulated on the basis of spectroscopic data. The geometric parameters are normal and the angle between the planes of the two ring systems is 59.74 (2) degrees. The crystal packing is influenced by(More)
Streptomyces sp. strain C34, isolated from soil collected in the Chilean hyper-arid Atacama Desert, was cultured on different media, resulting in the isolation and identification of four new ansamycin-type polyketides. The organism was selected for chemical investigation on the basis of a genome-mining PCR-based experiment targeting the gene encoding(More)
The title compound {systematic name: (+)-(S)-3-[5-cyano-2(4̄uorophenyl)-1,3-dihydroisobenzofuran-2yl]propanaminium oxalate oxalic acid 0.325-hydrate}, 2C20H22FN2O + C2O4 C2H2O4 0.325H2O, is a molecular salt of the N-protonated escitalopram cation. As well as charge-balancing oxalate dianions, neutral molecules of oxalic acid are present. The component(More)
The title compound (systematic name: 10,11-dihydro-5H-dibenz[b,f]azepine-5-carboxamide), C15H14N2O, is shown to crystallize as an orthorhombic polymorph to complement the known monoclinic form. The molecular conformations of both forms are very similar, involving a bent conformation for the seven-membered azepine ring and an overall ;butterfly' shape. The(More)
The racemic title compound, C15H12Br2O, crystallizes in a non-centrosymmetric structure and displays a significant non-linear optical response to red light. The crystal packing is influenced by C-H...O and C-H...pi interactions. One of the former bonds has a short H...O separation of 2.27 angstroms.
An improved current-mode CMOS voltage reference derives its temperature independent characteristic from two temperature dependent currents which are summed together into a resistor to generate the reference voltage. A CMOS proportional to absolute temperature (FTAT) current generator using substrate bipolar transistors creates the current that increases(More)