- Assessment of the in vitro and in vivo toxicity of 3,4- dihydroxyphenylacetaldehyde (DOPAL)
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This work was carried out in order to evaluate the in vitro and in vivo toxicity of 3,4-dihydroxyphenylacetaldehyde (DOPAL). This aldehyde is formed from dopamine (DA) by monoamine oxidases (MAO) and is mainly oxidised to 3,4-dihydroxyphenylacetic acid by
- Bonnet,Legros,Janin,Dourmap,Costentin
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- 3,4-Dihydroxystyrene Dimers, Inducers of Larval Metamorphosis in Ascidians, from a Marine Sponge Jaspis sp.
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Four new 3,4-dihydroxystyrene dimers (3,4,5, and 9) have been isolated from a marine sponge Jaspis sp. along with the known narains (1 and 2), of which 3-5 induced metamorphosis of ascidian Halocynthia roretzi larvae.Structures of these metabolites were elucidated on the basis of spectral data.Biogenesis of these compounds is also discussed.
- Tsukamoto, Sachiko,Kato, Haruko,Hirota, Hiroshi,Fusetani, Nobuhiro
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- Synthesis of a biochemically important aldehyde, 3,4- dihydroxyphenylacetaldehyde
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3,4-Dihydroxyphenylacetaldehyde (DOPAL) is an important precursor of the major brain metabolites of dopamine, 3,4-dihydroxyphenylacetic acid and 4- hydroxy-3-methoxyphenylacetic acid. A new method for the synthesis of DOPAL from piperonal is described. We report for the first time the physical and chemical characteristics of DOPAL. Its importance for research in Parkinson's disease and Alzheimer's disease is discussed.
- Li, Shu Wen,Spaziano, Vincent T.,Burke, William J.
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- Transaminase-Mediated Amine Borrowing via Shuttle Biocatalysis
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Shuttle catalysis has emerged as a useful methodology for the reversible transfer of small functional groups, such as CO and HCN, and goes far beyond transfer hydrogenation chemistry. While a biocatalytic hydrogen-borrowing methodology is well established, the biocatalytic borrowing of alternative functional groups has not yet been realized. Herein, we present a new concept of amine borrowing via biocatalytic shuttle catalysis, which has no counterpart in chemo-shuttle catalysis and allows efficient intermolecular amine shuttling to generate reactive intermediates in situ. By coupling this dynamic exchange with an irreversible downstream step to displace the reaction equilibrium in the forward direction, high conversion to target products can be achieved. We showcase the potential of this amine-borrowing methodology using a biocatalytic equivalent of both the Knorr-pyrrole synthesis and Pictet-Spengler reaction.
- Taday, Freya,Ryan, James,O’Sullivan, Rachel,O’Reilly, Elaine
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supporting information
p. 74 - 79
(2022/01/04)
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- Synthetic Evidence of the Amadori-Type Alkylation of Biogenic Amines by the Neurotoxic Metabolite Dopegal
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The neurotransmitter metabolite 3,4-dihydroxy-phenylglycolaldehyde (dopegal) damages neurons and the myocardium by protein cross-linking, resulting in conglomerations and cell death. We investigated this process on a synthetic scale, leading to the discovery of an Amadori-type rearrangement of dopegal in the reaction with several amino acids and neuropeptides. This alkylation also occurs with neurotransmitters, suggesting an influence of dopegal on neurochemical processes. The rearrangement occurs readily under physiological conditions.
- J?rgensen, Steen Ingemann,Tromp, Dorette S.,Van Maarseveen, Jan H.,Vilím, Jan,Wanner, Martin J.,Zuidinga, Ed
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- Design and Use of de novo Cascades for the Biosynthesis of New Benzylisoquinoline Alkaloids
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The benzylisoquinoline alkaloids (BIAs) are an important group of secondary metabolites from higher plants and have been reported to show significant biological activities. The production of BIAs through synthetic biology approaches provides a higher-yielding strategy than traditional synthetic methods or isolation from plant material. However, the reconstruction of BIA pathways in microorganisms by combining heterologous enzymes can also give access to BIAs through cascade reactions. Most importantly, non-natural BIAs can be generated through such artificial pathways. In the current study, we describe the use of tyrosinases and decarboxylases and combine these with a transaminase enzyme and norcoclaurine synthase for the efficient synthesis of several BIAs, including six non-natural alkaloids, in cascades from l-tyrosine and analogues.
- Wang, Yu,Tappertzhofen, Nadine,Méndez-Sánchez, Daniel,Bawn, Maria,Lyu, Boyu,Ward, John M.,Hailes, Helen C.
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p. 10120 - 10125
(2019/06/27)
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- Transaminase-Catalyzed Continuous Synthesis of Biogenic Aldehydes
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The physiological role of biogenic aldehydes, such as 3,4-dihydroxyphenylacetaldehyde (DOPAL), has been associated with cardiovascular and neurodegenerative disorders. The availability of these substrates is limited and robust synthetic methodologies would greatly facilitate further biological studies. Herein, a transaminase-mediated single-step process in continuous mode, which leads to excellent product yields (90–95 %), is reported. Coimmobilization of the pyridoxal phosphate (PLP) cofactor eliminated the need for exogenous addition of this reagent without affecting the longevity of the system, delivering a truly self-sufficient process.
- Contente, Martina L.,Paradisi, Francesca
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p. 2830 - 2833
(2019/08/12)
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- One-pot triangular chemoenzymatic cascades for the syntheses of chiral alkaloids from dopamine
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We describe novel chemoenzymatic routes to (S)-benzylisoquinoline and (S)-tetrahydroprotoberberine alkaloids using the enzymes transaminase (TAm) and norcoclaurine synthase (NCS) in a one-pot, one-substrate 'triangular' cascade. Employment of up to two C-
- Lichman,Lamming,Pesnot,Smith,Hailes,Ward
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supporting information
p. 852 - 855
(2015/03/04)
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- Exploring the synthetic applicability of a new carboxylic acid reductase from Segniliparus rotundus DSM 44985
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A new carboxylic acid reductase (CAR) gene from Segniliparus rotundus DSM 44985 was overexpressed in Escherichia coli. The recombinant enzyme exhibited high activity toward a variety of aromatic and aliphatic carboxylic acids. Especially, it effectively reduced 4-hydroxybenzoic acid (8a) and 4-nitrobenzoic acid (19a), toward which the known Nocardia CAR exhibited no or little activity. The recombinant E. coli cells co-expressing the Segniliparus CAR and Nocardia PPTase genes catalyzed the reductions of vanillic acid (20a) and 3,4-dihydroxyphenylacetic acid (25a) to give vanillyl alcohol (20c) and 3-hydroxytyrosol (25c) with high yield, respectively. The endogenous aldehyde reductases of E. coli should be responsible for the further reduction of the produced aldehydes. These results demonstrated that Segniliparus CAR was a useful addition to the biocatalyst tool-box for the reduction of carboxylic acids and might find applications in the synthesis of valuable bio-based chemicals from renewable resources.
- Duan, Yitao,Yao, Peiyuan,Chen, Xi,Liu, Xiangtao,Zhang, Rui,Feng, Jinhui,Wu, Qiaqing,Zhu, Dunming
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- The catalytic potential of Coptis japonica NCS2 revealed - Development and utilisation of a fluorescamine-based assay ETI
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The versatility and potential of a norcoclaurine synthase (NCS) from Coptis japonica NCS2 has been investigated, together with the development and application of a novel fluorescence-based high-throughput assay using nearly forty amines/aldehydes. The stereocontrol exerted by CjNCS2 on selected non-natural substrates has been determined, where the tetrahydroisoquinolines (THIAs) were formed as the (1S)-isomer in >95% ee, as observed with the natural product norcoclaurine. Docking calculations involving THIA mechanism intermediates, utilising the reported Thalictrum flavum NCS X-ray crystallographic structure, were carried out and combined with the CjNCS2 screening results to further understand the mode of action of NCS. These findings suggested that in addition to the key active-site residues K122 and E110, D141 is also mechanistically essential for the enzymatic transformation. The exceptional tolerance of NCS towards aldehyde substrates is furthermore supported by our proposed mechanism in which the aldehydes protrude out of the enzymatic pocket. Copyright
- Pesnot, Thomas,Gershater, Markus C.,Ward, John M.,Hailes, Helen C.
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supporting information
p. 2997 - 3008
(2013/01/15)
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- Inhibitory property of the Piper betel phenolics against photosensitization-induced biological damages
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The Piper betel phenolics, allylpyrocatechol (APC) and chavibetol (CHV), were found to protect photosensitization-mediated lipid peroxidation (LPO) of rat liver mitochondria effectively, APC being significantly more potent. The better activity of APC vis-a-vis CHV could be attributed to its higher reactivity with 1O2, as revealed from the rate constant values of 1O2 quenching by the respective phenolics. APC also prevented the detrimental effects of the Type II photosensitization-induced toxicity to mouse fibroblast L929 cells. The results suggest that APC may play an important role in protecting biological systems against damage, by eliminating 1O2 generated from certain endogenous photosensitizers.
- Mula, Soumyaditya,Banerjee, Debashish,Patro, Birija S.,Bhattacharya, Sayanti,Barik, Atanu,Bandyopadhyay, Sandip K.,Chattopadhyay, Subrata
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p. 2932 - 2938
(2008/09/20)
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- Convenient syntheses of biogenic aldehydes, 3,4-dihydroxyphenylacetaldehyde and 3,4-dihydroxyphenylglycolaldehyde
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The title compounds were prepared from a common precursor, a bis-THP-protected dihydroxyphenylacetic acid methyl ester. Key steps are the introduction of the α-hydroxyl group by Davis oxaziridine reagent and formation of the aldehydes by DIBALH ester reduction.
- Narayanan, Jayan,Hayakawa, Yoshio,Fan, Junfa,Kirk, Kenneth L.
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p. 191 - 197
(2007/10/03)
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- Oxidation of 3-(3,4-dihydroxy phenyl)-L-alanine (levodopa) and 3-(3,4,dihydroxy phenyl)-2-methyl-L-alanine (methyl dopa) by manganese(III) in pyrophosphate media: Kinetic and mechanistic study
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Manganese(III) (Mn(III)) has been stabilized in weakly acidic solution by means of pyrophosphate and the nature of the complex was elucidated spectrophotometrically. Stoichiometry of Mn(III)-oxidation of levodopa and methyl dopa in pyrophosphate medium wa
- Sherigara,Kumara Swamy,Subrahmanyam,Ishwar Bhat
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p. 449 - 457
(2007/10/03)
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- Studies on the Chinese Crude Drug "Forsythiae Fructus." VII. A New Caffeoyl Glycoside from Forsythia viridissima
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In addition to a known caffeoyl glycoside of 3,4-dihydroxyphenethyl alcohol, acteoside (1), a new caffeoyl glycoside of β,3,4-trihydroxyphenethyl alcohol, designated as β-hydroxyacteoside (2), was isolated from the fruits of Forsythia viridissima LINDLEY (Oleaceae).The structure of 2 was established as β,3,4-trihydroxyphenethyl-O-α-L-rhamnopyranosyl-(1->3)-4-O-caffeoyl-β-D-glucopyranoside on the basis of analysis of the carbon-13 nuclear magnetic resonance spectrum and chemical evidence.Keywords - Forsythia viridissima; Oleaceae; acteoside; caffeoyl glycoside of β,3,4-trihydroxyphenethyl alcohol; β-hydroxyacteoside; 13C-NMR spect ra
- Kitagawa, Shizuka,Tsukamoto, Hiroki,Hisada, Sueo,Nishibe, Sansei
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p. 1209 - 1213
(2007/10/02)
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