Use of Diphenyliodonium Bromide in the Synthesis of Some N-Phenyl α-Amino Acids

McKerrow, Jason D.; Al‐Rawi, Jasim M. A.; Brooks, Peter

doi:10.1080/00397910903051259

Cited by 27 publications

(22 citation statements)

References 14 publications

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“…7A . The α proton in LRC is at 5.4 ppm, compared to 4.5 ppm in Tyr (Supplementary Table S6 ), suggesting linkage of XA to Tyr via the Tyr N group (given that the Tyr carboxylic acid is intact, see above, and N-phenyl Tyr has its α proton deshielded compared to Tyr) 30 . Since we already dismissed the XA -Tyr amide, Fig.…”

Section: Resultsmentioning

confidence: 99%

New Zealand glowworm (Arachnocampa luminosa) bioluminescence is produced by a firefly-like luciferase but an entirely new luciferin

Watkins

Sharpe

Perry

et al. 2018

Sci Rep

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The New Zealand glowworm, Arachnocampa luminosa, is well-known for displays of blue-green bioluminescence, but details of its bioluminescent chemistry have been elusive. The glowworm is evolutionarily distant from other bioluminescent creatures studied in detail, including the firefly. We have isolated and characterised the molecular components of the glowworm luciferase-luciferin system using chromatography, mass spectrometry and 1H NMR spectroscopy. The purified luciferase enzyme is in the same protein family as firefly luciferase (31% sequence identity). However, the luciferin substrate of this enzyme is produced from xanthurenic acid and tyrosine, and is entirely different to that of the firefly and known luciferins of other glowing creatures. A candidate luciferin structure is proposed, which needs to be confirmed by chemical synthesis and bioluminescence assays. These findings show that luciferases can evolve independently from the same family of enzymes to produce light using structurally different luciferins.

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Section: Resultsmentioning

confidence: 99%

New Zealand glowworm (Arachnocampa luminosa) bioluminescence is produced by a firefly-like luciferase but an entirely new luciferin

Watkins

Sharpe

Perry

et al. 2018

Sci Rep

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“…Based on the literature precedence we hoped that aldehydes would react better with 2‐hydroxyimino esters as compared to ketones. First, methyl l ‐leucinate ( 27 ) was oxidized with H 2 O 2 in the presence of sodium tungstate to oxime 28 . In the next step, oxime 28 was treated with acetaldehyde under basic conditions by adding 0.1 m NaOH in portions to the mixture.…”

Section: Resultsmentioning

confidence: 99%

“…The combined filtrates were concentrated, and the resulting oil was distilled under vacuum (oil pump, bath temperature < 50 °C). The colorless free amino acid ester 27 (49.8 g, 90 %) was kept in a fridge (–18 °C). 1 H NMR (400 MHz, CDCl 3 ): δ = 0.88, 0.90 (2 d, J = 6.7 Hz, 6H, 5‐H), 1.34–1.43 (m, 1H, 3‐H), 1.45–1.51 (m, 2H, NH 2 ), 1.49–1.57 (m, 1H, 3‐H), 1.74 (qqdd, J = 6.7, 6.7, 6.7, 6.7 Hz, 1H, 4‐H), 3.41–3.47 (m, 1H, 2‐H), 3.68 (s, 3H, OCH 3 ) ppm; 13 C NMR (100 MHz, CDCl 3 ): δ = 21.7, 22.9, 24.7 (C‐4, C‐5), 44.0 (C‐3), 51.8 (C‐2), 52.7 (OCH 3 ), 177.0 (C‐1) ppm.…”

Section: Methodsmentioning

confidence: 99%

Total Synthesis of the Natural Herbicide MBH‐001 and Analogues

et al. 2020

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The first total synthesis of the natural herbicide MBH-001 (1) is reported. Structurally it is a 2-methyloxazol-5(2H)-one with a (1-hydroxyethyl) substituent at the 2-position. By relying on cyclic nitrones, a flexible route to MBH-001 and relevant analogues was developed. Key steps include the reaction of a 2-hydroxyimino ester with an aldehyde to form a 5-oxo-2,5dihydrooxazole 3-oxide. In an aldol-type reaction, the anion of these cyclic nitrones reacted with an aldehyde at the 2-position.[a] Scheme 1. Retrosynthetic considerations for MBH-001 (1) and the issue of regioselectivity in reactions of oxazolones with electrophiles. Results and DiscussionInitial studies were performed on oxazolone 4b, obtained by the Steglich method from acylated amino acid [6] 10 using water soluble carbodiimide [7] 11 (Scheme 2). Reaction of aromatic aldehydes 12a-c with oxazolone 4b (isomer of 4a) in the presence of triethylamine or diisopropylethylamine (Hünig′s base) provided the desired addition products with the carbinol connected to C2 (Scheme 2). However, preliminary tests showed that these aryl analogues 13a-13c of MBH-001 have no significant herbicidal activity.Unfortunately, the reaction of oxazolone 4b with acetaldehyde under identical conditions took a different course (Scheme 3). Thus, it seems hydroxyalkylation takes places at C4 to form intermediate A. This intermediate could not be isolated since it reacted with another acetaldehyde molecule to intermediate B followed by opening of the oxazolone ring and formation of 1,3-dioxanone 14, whose structure was confirmed by a single-crystal X-ray diffraction. We cannot rule out that other stereoisomers are formed in this transformation. The aldol-like reaction between 4b and acetaldehyde might be diastereo-Eur.

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“…The folate metabolism inhibitors have antineoplastic activity especially in treating haematologic and solid tumours [ 43 , 44 ]. The synthetic pathway was mainly developed to enhance the efficiency and yield of the total synthesis starting from 2,6-diamino-4(3 H )-pyrimidinone through different condensation steps to the last peptide coupling with chiral glutamate [ 45 , 46 , 47 , 48 ]. Different structure-activity relationship modifications have been implemented either on substituted pyrrolo [2,3- d ] pyrimidine [ 49 , 50 , 51 ] or in the bridge between this substance and the benzoyl ring in the side chain [ 52 ].…”

Section: Pemetrexedmentioning

confidence: 99%

Mesenchymal Stromal Cells for Antineoplastic Drug Loading and Delivery

et al. 2017

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Mesenchymal stromal cells are a population of undifferentiated multipotent adult cells possessing extensive self-renewal properties and the potential to differentiate into a variety of mesenchymal lineage cells. They express broad anti-inflammatory and immunomodulatory activity on the immune system and after transplantation can interact with the surrounding microenvironment, promoting tissue healing and regeneration. For this reason, mesenchymal stromal cells have been widely used in regenerative medicine, both in preclinical and clinical settings. Another clinical application of mesenchymal stromal cells is the targeted delivery of chemotherapeutic agents to neoplastic cells, maximizing the cytotoxic activity against cancer cells and minimizing collateral damage to non-neoplastic tissues. Mesenchymal stem cells are home to the stroma of several primary and metastatic neoplasms and hence can be used as vectors for targeted delivery of antineoplastic drugs to the tumour microenvironment, thereby reducing systemic toxicity and maximizing antitumour effects. Paclitaxel and gemcitabine are the chemotherapeutic drugs best loaded by mesenchymal stromal cells and delivered to neoplastic cells, whereas other agents, like pemetrexed, are not internalized by mesenchymal stromal cells and therefore are not suitable for advanced antineoplastic therapy. This review focuses on the state of the art of advanced antineoplastic cell therapy and its future perspectives, emphasizing in vitro and in vivo preclinical results and future clinical applications.

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Use of Diphenyliodonium Bromide in the Synthesis of Some N-Phenyl α-Amino Acids

Cited by 27 publications

References 14 publications

New Zealand glowworm (Arachnocampa luminosa) bioluminescence is produced by a firefly-like luciferase but an entirely new luciferin

New Zealand glowworm (Arachnocampa luminosa) bioluminescence is produced by a firefly-like luciferase but an entirely new luciferin

Total Synthesis of the Natural Herbicide MBH‐001 and Analogues

Mesenchymal Stromal Cells for Antineoplastic Drug Loading and Delivery

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