PMID- 37101569
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20230701
IS  - 2694-2437 (Electronic)
IS  - 2694-2437 (Linking)
VI  - 2
IP  - 3
DP  - 2022 Jun 15
TI  - Continuous Flow Synthesis of A2E Guided by Design of Experiments and 
      High-Throughput Studies.
PG  - 297-306
LID - 10.1021/acsbiomedchemau.1c00060 [doi]
AB  - N-Retinylidene-N-retinylethanolamine (A2E) is the most studied lipid bisretinoid. 
      It forms lipofuscin deposits in the retinal pigment epithelium (RPE), causing 
      vision impairment and blindness in eye conditions, such as Stargardt's disease, 
      cone-rod dystrophy, Best's macular dystrophy, and potentially age-related macular 
      degeneration. Synthetic A2E is often used for inducing the accumulation of 
      lipofuscins within the lysosomes of RPE cells in culture as an in vitro surrogate 
      of retinal lipofuscin buildup, providing insights into the mechanisms of these 
      eye conditions. Many reports describing the use of synthetic A2E employ material 
      that has been prepared using a one-pot reaction of all-trans-retinal (ATR) and 
      ethanolamine at room temperature for 48 h. We have revisited this synthesis by 
      performing a design of experiments (DoE) and high-throughput experimentation 
      workflow that was tailored to identify the most productive combination of the 
      variables (temperature, solvent, and reagent equivalences) for optimization of 
      A2E yield. Our DoE findings revealed that the interaction of ethanolamine with 
      acetic acid and ATR was pivotal for the formation of A2E in high yield, 
      indicating that imine formation is the critical step in the reaction. Armed with 
      these results, we were able to optimize the method using a microfluidic reactor 
      system before upscaling those conditions for continuous flow synthesis of A2E. 
      This revised method enabled a more efficient production of material, from a 
      reaction time of 48 h to a residence time of 33 min, with an accompanying yield 
      improvement from 49 to 78%. Furthermore, we implemented a simple method to 
      evaluate the quality of the A2E produced using optical spectroscopy and LC-MS 
      characteristics to assure that the biological properties observed with A2E 
      samples are not confounded by the presence of oxidized impurities that are 
      commonly present in conventional A2E samples.
CI  - (c) 2022 The Authors. Published by American Chemical Society.
FAU - Murbach-Oliveira, Giulia
AU  - Murbach-Oliveira G
AUID- ORCID: 0000-0002-4863-3304
AD  - Department of Chemistry, Multidisciplinary Cancer Research Facility, Purdue 
      University, West Lafayette, Indiana 47907, United States.
FAU - Banerjee, Kalpita
AU  - Banerjee K
AD  - Weil Cornell Medical College, Ophthalmology Department, Dyson Research Institute, 
      1300 York Avenue, New York, New York 10065, United States.
FAU - Nociari, Marcelo M
AU  - Nociari MM
AD  - Weil Cornell Medical College, Ophthalmology Department, Dyson Research Institute, 
      1300 York Avenue, New York, New York 10065, United States.
FAU - Thompson, David H
AU  - Thompson DH
AUID- ORCID: 0000-0002-0746-1526
AD  - Department of Chemistry, Multidisciplinary Cancer Research Facility, Purdue 
      University, West Lafayette, Indiana 47907, United States.
LA  - eng
GR  - R01 EY027422/EY/NEI NIH HHS/United States
PT  - Journal Article
DEP - 20220218
PL  - United States
TA  - ACS Bio Med Chem Au
JT  - ACS bio & med chem Au
JID - 9918232604406676
PMC - PMC10114832
COIS- The authors declare no competing financial interest.
EDAT- 2022/02/18 00:00
MHDA- 2022/02/18 00:01
PMCR- 2022/02/18
CRDT- 2023/04/27 02:06
PHST- 2022/02/18 00:01 [medline]
PHST- 2022/02/18 00:00 [pubmed]
PHST- 2023/04/27 02:06 [entrez]
PHST- 2022/02/18 00:00 [pmc-release]
AID - 10.1021/acsbiomedchemau.1c00060 [doi]
PST - epublish
SO  - ACS Bio Med Chem Au. 2022 Feb 18;2(3):297-306. doi: 
      10.1021/acsbiomedchemau.1c00060. eCollection 2022 Jun 15.