2506-10-7Relevant articles and documents
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Slaytor,McFarlane
, p. 605,611 (1968)
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Formation of tetrahydroharman (1-methyl-1,2,3,4-tetrahydro-beta-carboline) by Helicobacter pylori in the presence of ethanol and tryptamine
Callaway, James C.,Airaksinen, Mauno M.,Salmela, Katja S.,Salaspuro, Mikko
, p. 1817 - 1821 (1996)
Helicobacter pylori contains alcohol dehydrogenase which oxidizes ethanol to acetaldehyde. In the present study, H. pylori cytosol was incubated in a buffered media at pH 6.0 and 7.4 in the presence of ethanol and tryptamine. Under these conditions, tetrahydroharman (1-methyl-tetrahydro-β-carboline) was produced as a condensation product of tryptamine and acetaldehyde. At pH 6.0, 20.60 ± 5.00% of the added tryptamine was converted to tetrahydroharman, while 27.00 ± 4.80% (mean ± SD) was converted at pH 7.4. Similar reactions between acetaldehyde and other dietary amines seem likely. Such biogenic alkaloids, if formed in vivo, might contribute to the dysphoric effects of alcohol.
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Gray et al.
, p. 2792,2796 (1954)
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Tandem cleavage of hydrogenated β- and γ-carbolines - New practical synthesis of tetrahydroazocino[4,5-b]indoles and tetrahydroazocino[5, 4-b]indoles showing acetylcholinesterase inhibitory activity
Voskressensky, Leonid G.,Borisova, Tatiana N.,Kulikova, Larisa N.,Varlamov, Alexej V.,Catto, Marco,Altomare, Cosimo,Carotti, Angelo
, p. 3128 - 3135 (2004)
Hydrogenated γ-carbolines underwent tandem piperidine ring cleavage on treatment with dimethyl acetylenedicarboxylate (DMAD) or ethyl propiolate (EP) in the presence of alcohols, producing 3-alkoxymethyl-substituted indoles in high yields. These compounds were cyclized to tetrahydroazocino[4,5-b]indoles in the presence of AlCl3. Hydrogenated β-carbolines produced tetrahydroazocino [5,4-b]indoles directly upon treatment with EP in ethanol. The resulting azocinoindole derivatives were subjected to a preliminary evaluation of their in vitro acetylcholinesterase (AChE) inhibitory activities. Most of them were found to inhibit AChE with IC50 values in the micromolar range, compound 17 being the most potent (IC50 = 8.7 μm). Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
Application of metal free aromatization to total synthesis of perlolyrin, flazin, eudistomin U and harmane
Santhanam, Srinath,Ramu, Abinaya,Baburaj, Baskar,Kalpatu Kuppusamy, Balasubramanian
, p. 2121 - 2127 (2020/03/04)
Application of our recently reported metal free reaction conditions to the total synthesis of the four different and selective biologically interesting β-carboline natural products is reported. Using this simple methodology, flazin, perlolyrine, eudistomin U and harmane containing heteroaryl and alkyl substituents at C1 position were synthesized in good yields. (Figure presented.).
Inverted Binding of Non-natural Substrates in Strictosidine Synthase Leads to a Switch of Stereochemical Outcome in Enzyme-Catalyzed Pictet-Spengler Reactions
Eger, Elisabeth,Simon, Adam,Sharma, Mahima,Yang, Song,Breukelaar, Willem B.,Grogan, Gideon,Houk,Kroutil, Wolfgang
supporting information, p. 792 - 800 (2020/01/31)
The Pictet-Spengler reaction is a valuable route to 1,2,3,4-tetrahydro-β-carboline (THBC) and isoquinoline scaffolds found in many important pharmaceuticals. Strictosidine synthase (STR) catalyzes the Pictet-Spengler condensation of tryptamine and the aldehyde secologanin to give (S)-strictosidine as a key intermediate in indole alkaloid biosynthesis. STRs also accept short-chain aliphatic aldehydes to give enantioenriched alkaloid products with up to 99% ee STRs are thus valuable asymmetric organocatalysts for applications in organic synthesis. The STR catalysis of reactions of small aldehydes gives an unexpected switch in stereopreference, leading to formation of the (R)-products. Here we report a rationale for the formation of the (R)-configured products by the STR enzyme from Ophiorrhiza pumila (OpSTR) using a combination of X-ray crystallography, mutational, and molecular dynamics (MD) studies. We discovered that short-chain aldehydes bind in an inverted fashion compared to secologanin leading to the inverted stereopreference for the observed (R)-product in those cases. The study demonstrates that the same catalyst can have two different productive binding modes for one substrate but give different absolute configuration of the products by binding the aldehyde substrate differently. These results will guide future engineering of STRs and related enzymes for biocatalytic applications.
