The influence of D-Leu residues on the helical structures of L-Leu-based-nonapeptides was investigated. Specifically, the preferred conformations of four diastereomeric nonapeptides, Boc-(L-Leu-L-Leu-Aib)3-OMe (1); Boc-(L-Leu-L-Leu-Aib)2-L-Leu-D-Leu-Aib-OMe (2), which contained one D-Leu residue; Boc-L-Leu-D-Leu-Aib-L-Leu-L-Leu-Aib-L-Leu-D-Leu-Aib-OMe (3), which contained two D-Leu residues; an...

OBJECTIVES Botryoid odontogenic cyst (BOC) is considered as an unusual multilocular variant of lateral periodontal cyst (LPC). Review of the literature indicates that this lesion has higher risk of recurrence than LPC, but objective reasons are still unknown. The aim of this study is identify main clinical and pathological variables associated with the risk of recurrence. STUDY DESIGN A compl...

PURPOSE To identify significant clinical and radiological findings that distinguish rhino-orbito-cerebral mucormycosis (ROCM) from bacterial orbital cellulitis (BOC). METHODS This study was retrospective, multicenter, case-control study that enrolled 34 cases; 14 cases were diagnosed with ROCM and 20 cases were diagnosed with BOC at three different tertiary hospitals between 2005 and 2013. Th...

The thiol ester N-t-Boc-L-alanine-p-nitrothiophenyl ester (Boc-Ala-SNp) was synthesized and applied as an ultrastructural cytochemical substrate for intracellular elastase-like enzymes. Mature human neutrophils incubated with Boc-Ala-SNp and gold ions generate an electron-dense reaction product, gold p-nitrothiophenolate, which is found in the nuclear membrane, Golgi complex, endoplasmic reticu...

New Global Navigation Satellite System (GNSS) satellites will bring common, interoperable GNSS signals on L1. These new signals, L1C Global Positioning System (GPS)/QuasiZenith Satellite System (QZSS) L1C and Galileo E1 Open Service (OS), promise performance improvements in many areas. One key area is that these signals, which use binary offset carrier (BOC) and multiplexed BOC (MBOC), will pro...

A synthetic study on the preparation of N-Boc α-amino sulfoxides has revealed an unexpected instability which is believed to be due to α-elimination of the sulfoxide to give an iminium ion. Full synthetic details are reported on two main synthetic routes: lithiation and sulfinate trapping of N-Boc heterocycles and oxidation of N-Boc α-amino sulfides. Six novel α-amino sulfoxides were successful...

We have developed a convenient method for the direct synthesis of peptide thioesters, versatile intermediates for peptide ligation and cyclic peptide synthesis. The technology uses a modified Boc SPPS strategy that avoids the use of anhydrous HF. Boc in situ neutralization protocols are used in combination with Merrifield hydroxymethyl resin and TFA/TMSBr cleavage. Avoiding HF extends the scope...

Cholic acid 2a has been converted into two new orthogonally-protected triamino scaffolds, 13 and 14. The synthesis proceeds via the bis-Boc-NH-substituted azide 10, for which an improved preparation is described. After removal of the Boc groups, the two axial amines are differentiated through a novel monoprotection employing 1-(2-nitrobenzenesulfonyloxy)-benzotriazole 29. Regioselectivity of > ...

We describe the synthesis of bromo-tert-butyloxycarbonyl (Br-t-BOC)-amino-protected monomers 2-((1-bromo-2-methylpropan-2-yl)oxycarbonylamino)ethyl (meth)acrylate 3a,b. For this purpose, 2-isocyanatoethyl (meth)acrylate 1a,b was reacted with 1-bromo-2-methylpropan-2-ol (2a). The free radical polymerization of (Br-t-BOC)-aminoethyl (meth)acrylates 3a,b yielded poly((Br-t-BOC)-aminoethyl (meth)ac...

Chronic hepatitis C virus infection is an important public health problem, and the standard treatment (combination of pegylated interferon-α and ribavirin) has an effectiveness rate of only 40%-50%. Novel virus-specific drugs have recently been designed, and multiple compounds are under development. The approval for the clinical use of direct-acting antivirals in 2011 (boceprevir [BOC] and tela...