Synthetic routes to trace constituents of algal pheromone bouqets and other information-imitating substances

Structural modifications of multifidene ( 1 ), viridiene ( 2 ) and ectocarpene ( 5 ) led to the synthesis of eleven new pheromone components or imitatin substances mostly by Grignard alkylation of cyclopentene and cycloheptadiene synthons. A new lactone α,ω dienol conversion is reported.     

Method for immobilization of liposomes in capillary electrophoresis by electrostatic interaction with derivatized agarose

A novel procedure for immobilization of liposomes inside fused-silica capillaries is demonstrated. First, the inner wall of the capillaries was coated with a positively charged polymer, composed of derivatized agarose. Subsequently, negatively charged liposomes were immobilized by electrostatic interaction on the polymer coating. The developed liposome coated capillaries were used as a nanoseparation tool for studying interactions between small drug compounds and liposomes. Part of this work was presented at the 15th International Symposium on Microscale Separations and Analysis, HPCE 2002, Stockholm, Sweden, April 2002.     

Synthesis of β-Glucuronides of Estradiol,Ethynylestradiol and Estrone

ABSTRACT

Improved syntheses for the 3-β-D-glucuronides of the steroidal sex hormones 17β-estradiol, 17α-ethynylestradiol and estrone are reported employing boron trifluoride diethyl etherate catalysis with tetraacetylated glucuronic acid or the corresponding imidate.     

Determination of the gas chromatographic elution sequences of the (+)- and (−)-enantiomers of stable atropisomeric PCBs on Chirasil-dex

Pure enantiomers of chiral (atropisomeric) polychlorinated biphenyls (PCBs) obtained by high-performance liquid chromatography were used to establish the gas chromatographic elution sequences of the (+)- and (−)-enantiomers of six PCB atropisomers on Chirasil-Dex. The elution order was found to be (−/+) for PCBs 84, 132, 136, and 176 and (+/−) for PCBs 135 and 174. The retention characteristics of all 19 tri- and tetra-ortho atropisomeric PCBs were also investigated. Nine of the atropisomers could be separated using this chiral selector. PCBs 95, 132, and 149 were completely resovled and PCBs 84, 91, 135, 136, 174, and 176 were partially separated (R = 0.7–0.9). All of the separated congeners are 2,3,6-substituted in at least one ring, and conversely – none of the congeners that lacks 2,3,6-substitution could be separated. Thus, chiral recognition and enantiomer separation seems to be strongly governed by 2,3,6-substitution.     

Chain transfer reactions in emulsion polymerization of butadiene/styrene

Calculation of regulating index r from M̄_W values determined by experiments is proposed. The calculation is based on the assumption that the M̄_W values only depend on the conversion and the regulating index in emulsion polymerization. On this basis the calculation of regulator concentration in the latex particles was also possible. M̄_W values calculated in this way and experimental M̄_W values show good agreement.     

Rank one transformations with singular spectral type

We show that a certain class of measures arising from generalized Riesz products is singular. In particular, cutting and stacking (i.e. rank one) transformations whose cuts do not grow too rapidly, have singular maximal spectral type. The precise condition is , wherew _h is the number of cuts at stagen. Supported by a Canada NSERC grant. Supported by an NSF grant.     

Deformed preprojective algebras of generalized Dynkin type

We introduce the class of deformed preprojective algebras of generalized Dynkin graphs (), (), , , and () and prove that it coincides with the class of all basic connected finite-dimensional self-injective algebras for which the inverse Nakayama shift of every non-projective simple module is isomorphic to its third syzygy .