51-67-2Relevant academic research and scientific papers
Singlet oxygen-responsive photorelease of tyramine
Jeong, Dong Yeun,Yi, Seung Yeon,You, Youngmin
, p. 1497 - 1500 (2021)
A system capable of photoreleasing tyramine has been developed. The photodonor system consists of an isoindole cage of tyramine and a biscyclometalated Ir(III) complex singlet oxygen (1O2) photosensitizer. Photoirradiation at a wavelength of 365 nm produces tyramine, as evidenced by mass spectrometry and 1H NMR spectroscopy. The photorelease proceeds through two steps involving the formation of a Diels–Alder-type [2 + 4] cycloadduct of 1O2, followed by the slow and spontaneous decomposition of the adduct into tyramine and 2-benzoylbenzophenon.
Two-step enzymatic synthesis of tyramine from raw pyruvate fermentation broth
Zhang, Hongjuan,Lu, Yang,Wu, Siping,Wei, Yu,Liu, Qian,Liu, Junzhong,Jiao, Qingcai
, p. 38 - 44 (2016)
Tyramine, as a metabolite of tyrosine, is an important intermediate in synthesizing some drugs and medicinal materials. In this study, an efficient method for producing tyramine was developed by a two-step biocatalytic reaction with recombinant tyrosine phenol-lyase whole cells and tyrosine decarboxylase immobilized cells. Raw pyruvate fermentation broth was used as substrate of tyrosine phenol-lyase to economically produce l-tyrosine. l-tyrosine was catalyzed by immobilized tyrosine decarboxylase cells to effectively synthesize tyramine. The conditions of two-step enzymatic catalysis reactions were optimized separately, and the influence of immobilization on tyrosine decarboxylase activity was investigated. In a scale up study, 94.3% l-tyrosine was obtained from raw pyruvate fermentation broth under the optimal conditions. l-Tyrosine was decarboxylated to tyramine with a high yield 91.2%. The total yield of tyramine could reach approximately 86% by this two-step biocatalytic reaction. This study provides us with a green strategy for efficient preparation of tyramine.
The production of tyramine: Via the selective hydrogenation of 4-hydroxybenzyl cyanide over a carbon-supported palladium catalyst
McAllister, Mairi I.,Boulho, Cédric,McMillan, Liam,Gilpin, Lauren F.,Wiedbrauk, Sandra,Brennan, Colin,Lennon, David
, p. 29392 - 29399 (2018)
The selective production of primary amines is a problem that plagues heterogeneously catalysed nitrile hydrogenation reactions. Whilst the target amine tyramine (HOC6H4CH2CH2NH2) is biochemically available through the action of enzymes, synthetic routes to this species are not widely reported. Here, a heterogeneously catalysed method is proposed that utilises a Pd/C catalyst to effect the selective hydrogenation of 4-hydroxybenzyl cyanide within a three-phase reactor. The aforementioned selectivity issues are overcome by adjustment of various experimental parameters (hydrogen supply, agitation rate, temperature, use of an auxiliary agent) that result in improved catalytic performance, such that the desired tyramine salt (tyramine hydrogen sulphate) can be produced in quantitative yield. Accordingly, through consideration of the interconnectivity of hydrogenation and hydrogenolysis processes, a selective synthetic strategy is achieved with the findings suitable for extension to other substrates of this nature.
Cytotoxic and α-glucosidase inhibitory metabolites from twigs and leaves of Phyllanthus mirabilis, a species endemic to limestone mountains
Chaiyosang, Boonyanoot,Kanokmedhakul, Kwanjai,Kanokmedhakul, Somdej,Laphookhieo, Surat,Phukhatmuen, Piyaporn,Pornpongrungrueng, Pimwadee,Somteds, Apisara,Yahuafai, Jantana
, (2021/12/01)
The first investigation of Phyllanthus mirabilis Müll.Arg. led to the isolation of six undescribed compounds including two tyramine derivatives: phyllatyramines A and B; three butenolide analogues, phyllantenolide, phyllantenocoside-O-gallate and epi-phyllantenocoside-O-gallate; and a flavanonol gallate, (?)-taxifolin-3-O-gallate; as well as two first isolated natural products, phyllatyramine C and phyllantenocoside; together with twenty-three known compounds. Their structures were elucidated by spectroscopic means. ECD spectra of all isolated butenolides were compared and assigned the configurations. Phyllatyramine A displayed weak cytotoxicity against the KB cell line, while phyllatyramines B and C showed weak cytotoxicity against KB and HeLa cell lines. In addition, phyllatyramine B and (?)-taxifolin-3-O-gallate showed more potent α-glucosidase inhibitory activity than the standard acarbose 3.4 and 5.8 fold, respectively.
AFMT ANALOGS AND THEIR USE IN METHODS OF TREATING PARKINSON'S DISEASE
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Page/Page column 6, (2021/10/30)
The present disclosure provides compounds of formula (I), (II), and (la): Methods of preparing these molecules and their use for treatment of Parkinson's Disease are described.
Multienzyme One-Pot Cascades Incorporating Methyltransferases for the Strategic Diversification of Tetrahydroisoquinoline Alkaloids
Andexer, Jennifer N.,Cárdenas-Fernández, Max,Hailes, Helen C.,Méndez-Sánchez, Daniel,Richter, Michael,Roddan, Rebecca,Siegrist, Jutta,Subrizi, Fabiana,Thair, Benjamin,Wang, Yu,Ward, John M.
supporting information, p. 18673 - 18679 (2021/07/19)
The tetrahydroisoquinoline (THIQ) ring system is present in a large variety of structurally diverse natural products exhibiting a wide range of biological activities. Routes to mimic the biosynthetic pathways to such alkaloids, by building cascade reactions in vitro, represents a successful strategy and can offer better stereoselectivities than traditional synthetic methods. S-Adenosylmethionine (SAM)-dependent methyltransferases are crucial in the biosynthesis and diversification of THIQs; however, their application is often limited in vitro by the high cost of SAM and low substrate scope. In this study, we describe the use of methyltransferases in vitro in multi-enzyme cascades, including for the generation of SAM in situ. Up to seven enzymes were used for the regioselective diversification of natural and non-natural THIQs on an enzymatic preparative scale. Regioselectivites of the methyltransferases were dependent on the group at C-1 and presence of fluorine in the THIQs. An interesting dual activity was also discovered for the catechol methyltransferases used, which were found to be able to regioselectively methylate two different catechols in a single molecule.
Enantioselective Sequential-Flow Synthesis of Baclofen Precursor via Asymmetric 1,4-Addition and Chemoselective Hydrogenation on Platinum/Carbon/Calcium Phosphate Composites
Furiya, Yuichi,Ishitani, Haruro,Kobayashi, Shu
, (2020/05/05)
Continuous-flow synthesis of baclofen precursor (2) was achieved using achiral and chiral heterogeneous catalysts in high yield with high enantioselectivity. The key steps are chiral calcium-catalyzed asymmetric 1,4-addition of a malonate to a nitroalkene and chemoselective reduction of a nitro compound to the corresponding amino compound by using molecular hydrogen. A dimethylpolysilane (DMPS)-modified platinum catalyst supported on activated carbon (AC) and calcium phosphate (CP) has been developed that has remarkable activity for the selective hydrogenation of nitro compounds.
Biomimetic synthesis of galantamine: Via laccase/TEMPO mediated oxidative coupling
Baratto, Maria Camilla,Bizzarri, Bruno Mattia,Botta, Lorenzo,Pogni, Rebecca,Saladino, Raffaele,Zippilli, Claudio
, p. 10897 - 10903 (2020/03/27)
Laccase-mediated intramolecular oxidative radical coupling of N-formyl-2-bromo-O-methylnorbelladine afforded a novel and isolable spirocyclohexadienonic intermediate of galantamine. High yield and conversion of substrate were obtained in the presence of the redox mediator 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO). This laccase procedure, with an overall yield of 34%, represents a scalable and environmentally friendly alternative to previously reported syntheses of galantamine based on the use of potassium ferricyanide as an unspecific radical coupling reagent.
Facile in Vitro Biocatalytic Production of Diverse Tryptamines
McDonald, Allwin D.,Perkins, Lydia J.,Buller, Andrew R.
, p. 1939 - 1944 (2019/07/08)
Tryptamines are a medicinally important class of small molecules that serve as precursors to more complex, clinically used indole alkaloid natural products. Typically, tryptamine analogues are prepared from indoles through multistep synthetic routes. In the natural world, the desirable tryptamine synthon is produced in a single step by l-tryptophan decarboxylases (TDCs). However, no TDCs are known to combine high activity and substrate promiscuity, which might enable a practical biocatalytic route to tryptamine analogues. We have now identified the TDC from Ruminococcus gnavus as the first highly active and promiscuous member of this enzyme family. RgnTDC performs up to 96 000 turnovers and readily accommodates tryptophan analogues with substituents at the 4, 5, 6, and 7 positions, as well as alternative heterocycles, thus enabling the facile biocatalytic synthesis of >20 tryptamine analogues. We demonstrate the utility of this enzyme in a two-step biocatalytic sequence with an engineered tryptophan synthase to afford an efficient, cost-effective route to tryptamines from commercially available indole starting materials.
Design and Use of de novo Cascades for the Biosynthesis of New Benzylisoquinoline Alkaloids
Wang, Yu,Tappertzhofen, Nadine,Méndez-Sánchez, Daniel,Bawn, Maria,Lyu, Boyu,Ward, John M.,Hailes, Helen C.
supporting information, p. 10120 - 10125 (2019/06/27)
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.
