The precise crystal and molecular structure of melampodin, C(21)H(24)O(9), was determined from three-dimensional neutron diffraction data collected by counter techniques and phases by direct statistical methods. Crystals are orthorhombic, P2(1)2(1)2(1), a = 8,990(9), b = 14.352(14), c = 16.294(16) A, V = 2102 A(3), d(calc.) = 1.328 g.cm(-3), Z = 4 molecules per unit cell. The structural model w...

BACKGROUND The presence of mitral valve prolapse (MVP) in congenital heart disease (CHD) patients is not well described. Tetralogy of Fallot (TOF) is the most common cyanotic CHD associated with overall good long-term survival after palliation. Since MVP is more often identified in adults and TOF patients are now surviving longer, we thus sought to perform this cohort study with a case-control ...

We report an efficient and highly stereoselective strategy for the synthesis of Aspidosperma alkaloids based on the transannular cyclization of a chiral lactam precursor. Three new stereocenters are formed in this key step with excellent diastereoselectivity due to the conformational bias of the cyclization precursor, leading to a versatile pentacyclic intermediate. A subsequent stereoselective...

Background Patients who undergo surgical repair of Tetralogy of Fallot (TOF) often experience abnormal remodeling of the right ventricle (RV), notably with chamber dilatation and associated dysfunction. The ideal surgical technique is controversial, but RV outflow tract repair utilizing a transannular patch (TAP) is employed to overcome the RV outflow tract obstruction in many patients with TOF...

T 9 S synthesized, where X = Gly (l), L-Ala (2), D-Ala (3), Aib (4) and L&U (5). ‘H NMR studies at 270 MHz in CDCI, and (CD@0 provide evidence of a Pro-X /?-turn conformation, stabilized by a transannular 4-l hydrogen bond involving the Cys(4) NH, in all the peptides. In addition peptides 2,4 and 5 also possess a second intramolecular hydrogen bond involving the -NHMe group. The spectroscopic d...