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Articles Archive for January 2010

Still In The RBF »

[24 Jan 2010 | 62 Comments | 23,978 views]
Crambidine

Gin, Perl, Ide, Prajapati, Perfect, Duron. JACS, 2010, ASAP. DOI: 10.1021/ja910831k.
When I see targets containing guanidine moieties these days, I immediately think of David Gin, which goes to show how much he owns that motif just now.  Looking back into the murky past of Tot Syn, an earlier post covered Gin’s synthesis of Batzelladine A, which was fairly guanidine-tastic.  This bad-boy only has one, but with a bit of “anticancer, anti-HIV, antifungal, and Ca2+ ion channel blocking [activity]“, that grant-form presumably filled itself, especially at MSKCC.  However, …

Still In The RBF »

[18 Jan 2010 | 16 Comments | 16,278 views]
Hyperforin

Shibasaki, Kanai, Shimizu, Shi, Usuda. ACIEE, 2010, EarlyView. DOI: 10.1002/anie.200906678. ; Shibasaki, Kanai, Kuramochi, Usuda. Org. Lett., 2004, 6, 4387. DOI: 10.1021/ol048018s. 
Three amazingly tough targets completed in (almost) as many months – you can’t tell me that total synthesis is stifled.  Hyperforin has been staining the white-boards of many a lab for decades – the isolation (reported in Antibiotik…) was way back in ’71, and has resisted synthesis until now.  Shibasaki himself has been working on it for quite a while, as you’ll have seen in the header – a key …

Fresh Meat »

[11 Jan 2010 | 41 Comments | 42,431 views]
Piperkadsin C [Isolation] – Updated

Lee, Kim, Choi, Ha, Kim. BOMCL, 2010, 20, 409-412. DOI: 10.1016/j.bmcl.2009.10.016.
The Tot. Syn. bull-shit detector is at eleven just now, having just read Derek Lowe’s post on Piperkadsin C.  This natural product was isolated by Kang Ro Lee of Sungkyunkwan University in a assay-guided chromatographic separation of isolates from Piper kadsura (Piperaceae).  It doesn’t take much more than a glance to see that something seems very wrong with this structure, as it seems to contain a bridged cyclobutene, partially containing a dieneone.  From a chemical stability aspect, this is scary enough, …

Still In The RBF »

[10 Jan 2010 | 17 Comments | 14,081 views]
Isatisine A

Kerr, Karadeolian. ACIEE, 2010, EarlyView. DOI: 10.1002/anie.200906632.
It’s always going to be a tough situation for the article I blog following something like Palau’amine, but this short and sweet synthesis by Michael Kerr of the University of Western Ontario (in the other London – which I visited in ’95) is as good as can be.  The rationale for it’s investigation is also pertinant, as it turns out that Isatisine A is a moderately active HIV isolate (EC50 of 38 ?m).  A secondary interest in the isolation was …