19641-90-8

Upstream product

• 28104-71-4 (S)-(+)-N-Acetyl-3-<3,4-(methylendioxy)phenyl>alanin 
• 120-57-0 piperonal 
• 51703-92-5 N-acetyl-(R,S)-3,4-methylenedioxyphenylalanine methyl ester 
• 537-55-3 N-acetyl-L-tyrosine 
• 60470-83-9 2-methyl-4-(3,4-methylenedioxyphenylmethylene)-5(4H)-oxazolone 
• 59-92-7 levodopa 
• 108-24-7 acetic anhydride 
• 5796-17-8 D-Dopa 

Downstream Products

• 1258525-72-2 N-acetyl-L-o-hydroxytyrosine-L-alanine methyl ester 
• 32161-30-1 (S)-3,4-dimethoxyphenylalanine 
• 5796-17-8 D-Dopa 

Relevant academic research and scientific papers

Selective inactivation of serine proteases by nonheme iron complexes

Oxidative inactivation of the serine proteases trypsin and chymotrypsin by nonheme iron complexes is described. The nonheme ligands N4Py (1) and derivative 3CG-N4Py (2), which contains a pendant guanidinium group, were used as ligands for iron. Ferryl (Fe

An efficient preparation of mulberroside a from the branch bark of mulberry and its effect on the inhibition of tyrosinase activity

A bioactive ingredient in an ethanol extract from the branch bark of cultivated mulberry Husang-32 (Morus multicaulis Perr.) was isolated using a macroporous resin column. The primary component, which was purified by semi-preparative highperformance liqui

Hydrogen/deuterium exchange of cross-linkable α-amino acid derivatives in deuterated triflic acid

In this paper we report here a hydrogen/deuterium exchange (H/D exchange) of cross-linkable α-amino acid derivatives with deuterated trifluoromethanesulfonic acid (TfOD). H/D exchange with TfOD was easily applied to o-catechol containing phenylalanine (DOPA) within an hour. A partial H/D exchange was observed for trifluoromethyldiazirinyl (TFMD) phenylalanine derivatives. N-Acetyl-protected natural aromatic α-amino acids (Tyr and Trp) were more effective in H/D exchange than unprotected ones. The N-acetylated TFMD phenylalanine derivative afforded slightly higher H/D exchange than unprotected derivatives. An effective post-deuteration method for cross-linkable α-amino acid derivatives will be useful for the analysis of biological functions of bioactive peptides and proteins by mass spectrometry.

Tyrosine-lipid peroxide adducts from radical termination: Para coupling and intramolecular Diels-Alder cyclization

Free radical co-oxidation of polyunsaturated lipids with tyrosine or phenolic analogues of tyrosine gave rise to lipid peroxide-tyrosine (phenol) adducts in both aqueous micellar and organic solutions. The novel adducts were isolated and characterized by

Pictet-Spengler cyclization vs. Aminal formation: Competing reaction pathways of benzo[b][1,7]naphthyridines controlled by the configuration

Diastereoisomeric benzo[b][1,7]naphthyridines 13a,b were synthesized in nine steps from L-DOPA employing a Lewis acid-catalyzed cyclization of N-(4-methylpent-3-enyl)-a-amino aldehydes as the key step. Under aprotic Pictet-Spengler conditions, compounds 13a,b undergo different reaction pathways depending on the relative configuration. Whereas trans,cis-diastereoisomer 13a yielded the desired Pictet-Spengler cyclization product albeit in very low yield, the corresponding concave-shaped all-cis-diastereoisomer 13b undergoes intramolecular animal formation.

Synthesis of (S)-3,4-dihydroxyphenylalanine (L-DOPA) and unnatural α-amino acids via enzymatic resolution using alcalase

Enzymatic resolution has been used for the synthesis of L-DOPA with high optical purity.N-Acetyl-(R,S)-3,4-methylenedioxyphenylalanine methyl ester (2b) on enzymatic resolution by alcalase (Subtilisin Carlsberg) yields N-acetyl-(S)-3,4-methylenedioxyphenylalanine (3b) which upon acid treatment affords (S)-3,4-dihydroxyphenylalanine (L-DOPA) (4).Several optically active unnatural N-acetylated and N-benzoylated α-amino acids have been prepared by similar enzymatic resolution.

Dihydrocoumarin derivatives

Process for obtaining 5,6 or 6,7 or 7,8 dihydroxy coumarin or derivatives thereof, which are useful for lower blood pressure and for chemical sympathectomy by oxidizing 2,3 or 3,4 or 4,5 dihydroxyphenyl-propionic acid or derivatives thereof, and novel coumarin derivatives of the process.