Joseph P. Marino

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The directed TOCSY pulse sequence element transfers coherence predominantly into "forward-directed" antiphase coherences while simultaneously suppressing in-phase and "backward-directed" antiphase coherences. This novel selection principle, based on the "direction" of the target coherences, provides a new approach for the simplification of crowded spectra.(More)
A three-dimensional 1H, 13C, 31P triple resonance experiment, HCP-CCH-TOCSY, is presented which provides unambiguous through-bond correlation of all 1H ribose protons on the 5' and 3' sides of the intervening phosphorus along the backbone bonding network in 13C-labeled RNA oligonucleotides. The correlation of the complete ribose spin system to the(More)
Three experiments are introduced to determine a complete set of coupling constants in RNA oligomers. In the HCCH-E.COSY experiment, the vicinal proton-proton coupling constants can be measured with high accuracy. In the P-FIDS-CT-HSQC experiment, vicinal proton-phosphorus and carbon-phosphorus couplings are measured that depend on the phosphodiester(More)
The initial interaction between the ColE1 plasmid specific transcripts RNA I and RNA II, which function as antisense regulators of plasmid replication, comprises a transient complex between complementary loops found within the RNA secondary structures. Multidimensional heteronuclear magnetic resonance spectroscopy was used to characterize complexes formed(More)
Residual dipolar couplings can provide powerful restraints for determination and refinement of the solution structure of macromolecules. The application of these couplings in nucleic acid structure elucidation can have an especially dramatic impact, since they provide long-range restraints, typically absent in NOE and J-coupling measurements. Here we(More)
A new experiment for the measurement of nJ(C,P) coupling constants along the phosphodiester backbone in RNA and DNA based on a quantitative-J HCP experiment is presented. In addition to coupling constants, in which a carbon atom couples to only one phosphorus atom, both the intraresidual 3J(C4'i,Pi) and the sequential 3J(C4'i,Pi+1) for the C4' resonances(More)
A (1)H-(19)F spin state selective excitation (S(3)E) pulse sequence element has been applied in combination with (1)H homonuclear mixing to create E.COSY-type experiments designed to measure scalar J(HF2') and J(HH2') and residual dipolar D(HF2') and D(HH2') couplings in 2'-deoxy-2'-fluoro-sugars. The (1)H-(19)F S(3)E pulse sequence element, which resembles(More)
The copper-mediated S(N)2' displacement of enantiomerically pure allylic mesyloxy vinyl sulfoxides takes place with high yields and stereoselectivities. In these adducts, the newly created chiral center is adjacent to a vinyl sulfoxide functionality which should allow for subsequent chirality transfer operations. Alternatively, enantiopure alkenyl sulfones(More)
A new annulation sequence leading to the tetracyclic skeleton of the Lycopodium family of alkaloids is effected by using the tandem cycloaddition-cationic pi-cyclization reaction of an isomünchnone dipole as the key strategic element. Synthesis of the required alpha-diazo imide precursor involved treating 5-methylcyclohex-2-en-1-one with the organocopper(More)