When hydroquinone-O,Ooffiacetic acid is used as a linker arm in solid phase oligonucleotide synthesis, the time for NH4OH cleavage of oligodeoxy- or oligoribonucleotides is reduced to only 2 min. This allows increased productivity on automated DNA synthesizers without requiring any other modifications to existing reagents or synthesis and deprotection methods. The Q-linker may also be rapidly cleaved by milder reagents such as 5% NH4OH, potassium carbonate, anhydrous ammonia, t-butylamine or fluoride ion. However, the Q-linker is sufficiently stable for long-term storage at room temperature without degradation and no loss of material occurs during synthesis. The linker is also reasonably resistant to 20% piperidine/DMF, 0.5 M DBU/pyridine and 1:1 triethylamine/ethanol. The Q-linker can therefore serve as a general replacement for both succinyl and oxalyl linker arms.

No abstract

No abstract

The Chinese version of the NDI is a reliable and valid scale for measuring health-related quality of life and disease severity in Chinese patients with FD.

Nucleosides can be esterified to solid-phase supports using uronium or phosphonium coupling reagents and a coupling additive, such as 1-hydroxybenzotriazole (HOBT), 7-aza-1-hydroxybenzotriazole (HOAT), N-methylimidazole (NMI), or 4-(dimethylamino)pyridine (DMAP). However, DMAP was far superior to other additives and high nucleoside loadings (up to 60 micromol/g) and rapid coupling reactions (< or = 10 min) were possible. Hydroxyl-derivatized CPG was attached to nucleosides with 3'-succinyl or 3'-hydroquinone-O, O'-diacetic acid (HQDA or Q-Linker) carboxyl groups through a primary ester linkage. Alternatively, supports derivatized with succinic acid or the Q-Linker were attached directly to the 3'-OH group of nucleosides through a secondary ester linkage. Uronium reagents (HATU or HBTU) gave the best results with the HQDA linker arm, while the bromophosphonium (BrOP or PyBrOP) reagents were best with the succinyl linker arm. In all cases, the coupling reactions were much faster than previous methods using carbodiimide coupling reagents. The ease and speed of the reaction make this support derivatization procedure suitable for automated in situ couplings on DNA synthesizers.