Stereoconfiguration of endogenous N-malonyltryptophan in plants

Markova, T.; Gamburg, K. Z.

doi:10.1016/s0168-9452(96)04552-9

Cited by 5 publications

(12 citation statements)

References 12 publications

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“…We also see evidence in Figure 6 of several blueward moving, absorption features (primarily between −100 and −200 km s −1 ) that appear morphologically similar to the Discrete Absorption Components (DACs) observed previously in other spectral lines (Israelian & de Groot 1999;Markova 1986aMarkova , 2000. Figure 7 is a montage of a subset of the quotient spectra.…”

Section: Blue Absorption Changessupporting

confidence: 72%

“…Our work represents the first detection of DACs in the blue absorption trough of Hα, and their properties differ from those observed in other spectral lines (Israelian et al 1996;Markova 1986aMarkova , 2000. For example, the recurrence timescale of 1700 d is much larger than the 200 d interval found in earlier work, and the acceleration we measure is about a factor of 10 smaller than measured by others.…”

Section: Blue Absorption Changescontrasting

confidence: 70%

“…The DACs tend to appear over a radial velocity range of −90 to −200 km s −1 with an acceleration of −0.1 to −0.6 km s −1 d −1 . A recurrence timescale of ∼ 200 d is sometimes observed (Kolka 1983;Markova 1986a;Israelian et al 1996;Kolka 1998). These accelerations are much slower and the timescales are much longer than those associated with DACs in the winds of O-stars (Kaper et al 1999).…”

Section: Introductionmentioning

confidence: 99%

“…These accelerations are much slower and the timescales are much longer than those associated with DACs in the winds of O-stars (Kaper et al 1999). The DACs in the spectrum of P Cygni may form in outward moving and dense shells (Kolka 1983;Lamers et al 1985;Markova 1986a;Israelian et al 1996), in spiral-shaped co-rotating interaction regions (CIRs; Cranmer & Owocki 1996;Markova 2000), or in dense clumps in the wind (Lépine & Moffat 2008).…”

Section: Introductionmentioning

confidence: 99%

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The Hα VARIATIONS OF THE LUMINOUS BLUE VARIABLE P CYGNI: DISCRETE ABSORPTION COMPONENTS AND THE SHORT S DORADUS-PHASE

Richardson¹,

Morrison²,

Gies³

et al. 2011

The Astronomical Journal

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P Cygni is a prototype of the Luminous Blue Variables (or S Doradus variables), and the star displays photometric and emission line variability on a timescale of years (known as the "short S Doradus phase" variations). Here we present new high resolution Hα spectroscopy of P Cyg that we combine with earlier spectra and concurrent V -band photometry to document the emission and continuum flux variations over a 24 y time span. We show that the emission and continuum fluxes vary in concert on timescales of 1.6 y and longer, but differ on shorter timescales. The Hα profile shape also varies on the photometric timescales, and we describe the observed co-variations of the emission peak and absorption

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Section: Blue Absorption Changessupporting

confidence: 72%

Section: Blue Absorption Changescontrasting

confidence: 70%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The Hα VARIATIONS OF THE LUMINOUS BLUE VARIABLE P CYGNI: DISCRETE ABSORPTION COMPONENTS AND THE SHORT S DORADUS-PHASE

Richardson¹,

Morrison²,

Gies³

et al. 2011

The Astronomical Journal

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“…This compound (Figure b) was first reported by Good and Andreae () as a metabolic product of tryptophan in Spinacia oleracea (spinach) leaves, and drew a lot of attention in the following decades for the possibility of it being an auxin precursor (Rekoslavskaya, ; Ludwig‐Müller and Hilgenberg, ). There was also an intensive debate regarding the chirality of tryptophan in the molecule (Sakagami et al ., , ; Markova and Gamburg, ). Based on those previous studies, it is likely that the compound found in soybean is N (α)‐malonyl‐( S )‐tryptophan.…”

Section: Resultsmentioning

confidence: 99%

A facile means for the identification of indolic compounds from plant tissues

Hegeman

Cohen

2014

The Plant Journal

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SUMMARYThe bulk of indole-3-acetic acid (IAA) in plants is found in the form of conjugated molecules, yet past research on identifying these compounds has largely relied on methods that were both laborious and inefficient. Using recent advances in analytical instrumentation, we have developed a simple yet powerful liquid chromatography-mass spectrometry (LC-MS)-based method for the facile characterization of the small IAA conjugate profile of plants. The method uses the well-known quinolinium ion (m/z 130.0651) generated in MS processes as a signature with high mass accuracy that can be used to screen plant extracts for indolic compounds, including IAA conjugates. We reinvestigated Glycine max (soybean) for its indoles and found indole-3-acetyl-trytophan (IA-Trp) in addition to the already known indole-3-acetyl-aspartic acid (IA-Asp) and indole-3-acetyl-glutamic acid (IA-Glu) conjugates. Surprisingly, several organic acid conjugates of tryptophan were also discovered, many of which have not been reported in planta before. These compounds may have important physiological roles in tryptophan metabolism, which in turn can affect human nutrition. We also demonstrated the general applicability of this method by identifying indolic compounds in different plant tissues of diverse phylogenetic origins. It involves minimal sample preparation but can work in conjunction with sample enrichment techniques. This method enables quick screening of IAA conjugates in both previously characterized as well as uncharacterized species, and facilitates the identification of indolic compounds in general.

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