Date: Thu, 16 Jan 1997 12:13:21 -0600
Message-Id: <v0153050baf051de12e5c@[128.252.197.88]>
To: abrfhyp@cco.caltech.edu
From: rskubish@pharmdec.wustl.edu (Richard Skubish)
Subject: Ether precipitation after TFA cleavage
>Date: Wed, 25 Sep 1996 10:51:20 +0400
>From: Vladimir Titov <titov@ibch.siobc.ras.ru>
>Reply-To: titov@ibch.siobc.ras.ru
>Organization: Peptide Lab, Shemyakin-Ovchinnikov Institute Bioorganic Chemistry
>Mime-Version: 1.0
>Old-To: "Lefebvre, Jean" <JEAN.LEFEBVRE@nrc.ca>
>Cc: ABRF <abrf@aecom.yu.edu>
>Subject: Re: Ether precipitation after TFA cleavage
>To: Recipients of ABRF List <abrf@aecom.yu.edu>
>Sender: Association of Biomolecular Resource Facilities
><abrf-request@aecom.yu.edu>
>Precedence: bulk
>
>Lefebvre, Jean wrote:
>>
>> Hi,
>>
>> After TFA cleavage, our peptides are precipitated in Ethyl Ether.
>> We want to avoid to filter those solutions because it is very long since we
>> do about 24 at a time.
>> We think about centrifugatrion but Ether in centrifuge can explode with a
>> spark.
>> Does anyone have a suggestion...
>>
>> Jean Lefebvre
>> BRI/NRC
>> Montreal,P.Quebec
>> Canada
>>
>> E-Mail: lefebvre@biotech.lan.nrc.ca
>
>IMHO, many people nowadays are forgetting about a useful device called
>rotary evaporator. Though I work using Boc/HF, I use to dissolve
>peptides in TFA after deprotection. After evaporation and treatment with
>ether the crude usually forms a dense precipitate most of whch is
>sticking to the flask. The rest is very easy to filter off. Maybe, usage
>of cleavage cocktails with minimum scavengers as it was adviced in one
>of the previous discussions can help too.
>
>Disclaimer: I do not work for Buechi
>
>
>Vladimir Titov
>titov@ibch.siobc.ras.ru
>
Richard Skubish
rskubish@pharmdec.wustl.edu
314-362-0283
Washington University Medical School
Box 8103 - PNACL
660 S. Euclid
St. Louis, MO 63110