> -----Original Message-----
> From: Jeni Lauer-Fields [SMTP:jlauer@ACC.FAU.EDU]
> Sent: Monday, September 27, 1999 10:19 AM
> To: Recipients of ABRF List
> Subject: PepSyn-?capping?
>
> Hello,
>
> I have some questions for the synthetic experts out there. The last two
> peptides
> we've made have totally bombed. We're seeing an incredible amount of resin
>
> capping. I blamed the first failure on the presence of water in the
> HOBt/HBTU
> bottle or the DIEA bottle (both were changed just prior to synthesis). I
> remade
> the solutions with new dry bottles and the second synthesis was even
> worse. The
> good news is that we're incorporating a Lys(Dnp) residue so I can tell by
> looking at the resin that something went awry (not yellow enough). The bad
> news
> is that I can't tell from the monitor trace that there is a problem. A
> very
> small portion of the resin is synthesized to completion (as verified by
> MS).
>
> My questions are:
> 1) Am I wrong in thinking that water did this? Could it be something else?
> 2) We've opened no new reagents lately, so my guess is that something has
> gone
> bad. What is the most likely culprit? Our HOBt is the oldest, with HBTU
> second.
> The pip and DIEA are turned over so often they're never more than a month
> or two
> old.
>
> Thanks in advance for your assistance.
>
> Jeni
>
>
> Janelle Lauer-Fields
> Department of Chemistry & Biochemistry
> Florida Atlantic University
> 777 Glades Road
> Boca Raton, Florida 33431
> 561-297-2094/Fax 561-297-2759