Isolation of the retinal isomers from the isomerization of all-trans-retinal by flash countercurrent chromatography

He, Minfei; Du, Wenkai; Du, Qingbao; Zhang, Yun; Li, Bo; Ke, Changqian; Yang, Yong; Du, Qizhen

doi:10.1016/j.chroma.2012.11.022

Cited by 10 publications

(10 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This distribution of retinoid isomers was similar to that obtained with visible light-catalyzed photoisomerization of either the 11-cis-retinylidene Schiff base (Fig. S5) or all-trans retinal (35). The sample treated with IR light at 880 nm for 2 h retained only 20% of the original 11-cis-retinoids (Fig.…”

Section: Resultssupporting

confidence: 53%

Human infrared vision is triggered by two-photon chromophore isomerization

Palczewska

Vinberg

Stremplewski

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Vision relies on photoactivation of visual pigments in rod and cone photoreceptor cells of the retina. The human eye structure and the absorption spectra of pigments limit our visual perception of light. Our visual perception is most responsive to stimulating light in the 400-to 720-nm (visible) range. First, we demonstrate by psychophysical experiments that humans can perceive infrared laser emission as visible light. Moreover, we show that mammalian photoreceptors can be directly activated by near infrared light with a sensitivity that paradoxically increases at wavelengths above 900 nm, and display quadratic dependence on laser power, indicating a nonlinear optical process. Biochemical experiments with rhodopsin, cone visual pigments, and a chromophore model compound 11-cis-retinyl-propylamine Schiff base demonstrate the direct isomerization of visual chromophore by a two-photon chromophore isomerization. Indeed, quantum mechanics modeling indicates the feasibility of this mechanism. Together, these findings clearly show that human visual perception of near infrared light occurs by twophoton isomerization of visual pigments.visual pigment | two-photon absorption | rhodopsin | transretinal electrophysiology | multiscale modeling H uman vision is generally believed to be restricted to a visible light range, although >50% of the sun's radiation energy that reaches earth is in the infrared (IR) range (1). Human rod and cone visual pigments with the 11-cis-retinylidene chromophore absorb in the visible range, with absorption monotonically declining from their maxima of 430-560 nm toward longer wavelengths. The spectral sensitivity of human dim light perception matches well with the absorption spectrum of the rod visual pigment, rhodopsin (2, 3). Activation of visual pigments is temperature independent around their absorption peaks (λ max ), but at longer wavelengths, the lower energy photons must be supplemented by heat to achieve chromophore photoisomerization (4). Long wavelength-sensitive visual pigments of vertebrates exhibit maximal absorption at the ∼500-to ∼625-nm range. Pigments with λ max > 700 nm are theoretically possible, but the high noise due to spontaneous thermal activation would render them impractical (5). At human body temperature and with 1,050-nm stimulation, the sensitivity of the peripheral retina to one-photon (1PO) stimulation is less than 10 −12 of its maximum value at 505 nm (4, 6). Indeed, reports about human IR vision can be found in the literature, although they are fragmentary and do not describe the mechanism of this phenomenon.With the invention of radar during World War II, it was immediately questioned if pilots could detect high intensity radiation in the IR range of the spectrum. Wald and colleagues reported that at wavelengths above 800 nm, rod photoreceptors become more sensitive than cones, resulting in perception of IR signals as white light selectively in the peripheral retina (6). They proposed that relative spectral sensitivity declines monotonically toward longer wavele...

show abstract

Section: Resultssupporting

confidence: 53%

Human infrared vision is triggered by two-photon chromophore isomerization

Palczewska

Vinberg

Stremplewski

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…A shift in the retention times of retinaldehyde and retinoic acid after incubation with cells might represent trans-cis isomerization of retinoids. All-trans retinaldehyde can be converted into isoforms with different HPLC retention times [ 20 ], and cis isoform isomerization of all-trans retinaldehyde has been reported in retinal epithelial cells [ 21 ].…”

Section: Discussionmentioning

confidence: 99%

Inhibition of aldehyde dehydrogenase 1 enhances the cytotoxic effect of retinaldehyde on A549 cancer cells

et al. 2017

View full text Add to dashboard Cite

We hypothesized that aldehyde dehydrogenase1 (ALDH1) protects cancer cells from retinaldehyde-induced cytotoxicity, and that targeting this enzyme would enhance the therapeutic effect of retinaldehyde. ALDEFLUOR™ assays showed high ALDH activity in A549 and H522 cancer cells and low activity in H1666 and T47D cancer cells. Immunoblots showed that expression of ALDH1A1 and ALDH1A3 was high in A549 and H522 cells, but low in H1666 cells. HPLC confirmed that N, N-diethylaminobenzaldehyde (DEAB) inhibits ALDH-mediated disposal of retinaldehyde in A549 cells and lysates. Treatment of A549 cells with retinaldehyde in the presence of DEAB augmented reactive oxygen species production and decreased glucose uptake and oxygen consumption. Importantly, DEAB substantially potentiated the ability of retinaldehyde to dose-dependently suppress the survival of A549 and H522 cells, whereas the added effect of DEAB was minor in H1666 and T47D cells. Gene silencing with specific siRNA revealed that ALDH1A1 contributed to protection of A549 cells against retinaldehyde toxicity. These results demonstrate that ALDH1 confers protection against retinaldehyde toxicity in cancer cells.

show abstract

“…The literature since 2007 contains 28 examples (S3, Supporting Information ) of halogenated solvents used in CCS fractionation of natural product mixtures. 39 , 47 , 94 , 108 , 115 , 122 − 144 …”

Section: Solvent Systemsmentioning

confidence: 99%

Countercurrent Separation of Natural Products: An Update

et al. 2015

View full text Add to dashboard Cite

This work assesses the current instrumentation, method development, and applications in countercurrent chromatography (CCC) and centrifugal partition chromatography (CPC), collectively referred to as countercurrent separation (CCS). The article provides a critical review of the CCS literature from 2007 since our last review (J. Nat. Prod.2008, 71, 1489–1508), with a special emphasis on the applications of CCS in natural products research. The current state of CCS is reviewed in regard to three continuing topics (instrumentation, solvent system development, theory) and three new topics (optimization of parameters, workflow, bioactivity applications). The goals of this review are to deliver the necessary background with references for an up-to-date perspective of CCS, to point out its potential for the natural product scientist, and thereby to induce new applications in natural product chemistry, metabolome, and drug discovery research involving organisms from terrestrial and marine sources.

show abstract

Isolation of the retinal isomers from the isomerization of all-trans-retinal by flash countercurrent chromatography

Cited by 10 publications

References 14 publications

Human infrared vision is triggered by two-photon chromophore isomerization

Human infrared vision is triggered by two-photon chromophore isomerization

Inhibition of aldehyde dehydrogenase 1 enhances the cytotoxic effect of retinaldehyde on A549 cancer cells

Countercurrent Separation of Natural Products: An Update

Contact Info

Product

Resources

About