Inter- and intramolecular isotopic correlations in some cyanogenic glycosides and glucosinolates and their practical importance

Butzenlechner, Maria; Thimet, Susanne; Kempe, K.; Kexel, Hugo; Schmidt, Hanns‐Ludwig

doi:10.1016/0031-9422(96)00290-7

Cited by 18 publications

(8 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For the positions that are assumed to be derived from the nonaromatic part of the C 6 -C 3 molecule, the enrichment of the C6 T position relative to the C1 T (ΔC6 T − C1 T = 6.5‰) is consistent with the known enrichment in the carbon derived from the α-C (C2) of aromatic amino acids (47). An enrichment relative to the β-C (C3) of the same order is observed (Fig.…”

Section: Resultssupporting

confidence: 74%

A retro-biosynthetic approach to the prediction of biosynthetic pathways from position-specific isotope analysis as shown for tramadol

Romek

Nun

Remaud

et al. 2015

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

View full text Add to dashboard Cite

Tramadol, previously only known as a synthetic analgesic, has now been found in the bark and wood of roots of the African medicinal tree Nauclea latifolia. At present, no direct evidence is available as to the biosynthetic pathway of its unusual skeleton. To provide guidance as to possible biosynthetic precursors, we have adopted a novel approach of retro-biosynthesis based on the position-specific distribution of isotopes in the extracted compound. Relatively recent developments in isotope ratio monitoring by 13 C NMR spectrometry make possible the measurement of the nonstatistical position-specific natural abundance distribution of 13 C (δ 13 C i ) within the molecule with better than 1‰ precision. Very substantial variation in the 13 C positional distribution is found: between δ 13 C i = −11 and −53‰. Distribution is not random and it is argued that the pattern observed can substantially be interpreted in relation to known causes of isotope fractionation in natural products. Thus, a plausible biosynthetic scheme based on sound biosynthetic principals of precursorsubstrate relationships can be proposed. In addition, data obtained from the 18 O/ 16 O ratios in the oxygen atoms of the compound add support to the deductions made from the carbon isotope analysis. This paper shows how the use of 13 C NMR at natural abundance can help with proposing a biosynthetic route to compounds newly found in nature or those difficult to tackle by conventional means.NMR spectrometry | position-specific isotope analysis | retro-biosynthesis | tramadol | Nauclea latifolia

show abstract

Section: Resultssupporting

confidence: 74%

A retro-biosynthetic approach to the prediction of biosynthetic pathways from position-specific isotope analysis as shown for tramadol

Romek

Nun

Remaud

et al. 2015

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

View full text Add to dashboard Cite

show abstract

“…Starting in the 1990s, the groups of Schmidt ([39] and references therein), Melzer and O'Leary ( [40] and references therein), Hayes ([41] and references therein) among others tried to connect these data of inter-and intramolecular isotope ratios with the biochemistry of the related biosynthesis and/or degradation reactions. The characterisation of divergence in the isotopic signatures of diverse classes of metabolites [29,[42][43][44][45] and the heterogeneous distribution of carbon isotopes within biomolecules [9,41,[46][47][48][49][50] laid the ground for the understanding of the effects of changes in respiratory substrates and fragmentation fractionation on apparent respiratory fractionation and the related changes in the isotopic composition of organic mass. To find a biochemical explanation for the 13 C-enrichment of the CO 2 respired by peanut cotyledons, it might be useful to conduct labelling experiments with feeding of positionally 13 C-enriched metabolites like acetyl-CoA, fatty acids and amino acids.…”

Section: Ecophysiologal Research Enriched By Biochemical Resultsmentioning

confidence: 99%

Changes inδ¹³C of dark respired CO₂and organic matter of different organs during early ontogeny in peanut plants

Ghashghaie¹,

Badeck²,

Girardin³

et al. 2015

Isotopes in Environmental and Health Studies

View full text Add to dashboard Cite

Carbon isotope composition in respired CO2 and organic matter of individual organs were measured on peanut seedlings during early ontogeny in order to compare fractionation during heterotrophic growth and transition to autotrophy in a species with lipid seed reserves with earlier results obtained on beans. Despite a high lipid content in peanut seeds (48%) compared with bean seeds (1.5%), the isotope composition of leaf- and root-respired CO2 as well as its changes during ontogeny were similar to already published data on bean seedlings: leaf-respired CO2 became (13)C-enriched reaching -21.5‰, while root-respired CO2 became (13)C-depleted reaching around -31‰ at the four-leaf stage. The opposite respiratory fractionation in leaves vs. roots already reported for C3 herbs was thus confirmed for peanuts. However, contrarily to beans, the peanut cotyledon-respired CO2 was markedly (13)C-enriched, and its (13)C-depletion was noted from the two-leaf stage onwards only. Carbohydrate amounts being very low in peanut seeds, this cannot be attributed solely to their use as respiratory substrate. The potential role of isotope fractionation during glyoxylate cycle and/or gluconeogenesis on the (13)C-enriched cotyledon-respired CO2 is discussed.

show abstract

“…Examples include glucose (Rossman et al, 1991) Cyanogenic glucosides (Butzenlechner et al, 1996) and amino acids (Abelson et al, 1961).…”

Section: Introductionmentioning

confidence: 99%

Carbon isotope ratios of amylose, amylopectin and mutant starches

Scott¹,

Jane²,

Soundararajan³

1999

Phytochemistry

View full text Add to dashboard Cite

Carbon isotope ratios (expressed as d 13C values) were determined for various sources of starch and the starch fractions amylose and amylopectin. The d13 C values of amylose were consistently less negative, 0.4±2.3 -, than those of amylopectin in kernal starch from maize (Zea mays ) and barley (Hordeum vulgare ) and in tuber starch from potato (Solanum tuberosum ). Kernel starch isolated from the maize mutants wx1 and ae1, with known genetic lesions in the starch biosynthetic pathway, also showed signi®cant dierences in d 13C values. Collectively, these results suggest that variation in carbon isotope ratios in the amylose and amylopectin components of starch may be attributed to isotopic discrimination by the enzymes involved in starch biosynthesis. Published by Elsevier Science Ltd.

show abstract

Inter- and intramolecular isotopic correlations in some cyanogenic glycosides and glucosinolates and their practical importance

Cited by 18 publications

References 17 publications

A retro-biosynthetic approach to the prediction of biosynthetic pathways from position-specific isotope analysis as shown for tramadol

A retro-biosynthetic approach to the prediction of biosynthetic pathways from position-specific isotope analysis as shown for tramadol

Changes inδ¹³C of dark respired CO₂and organic matter of different organs during early ontogeny in peanut plants

Carbon isotope ratios of amylose, amylopectin and mutant starches

Contact Info

Product

Resources

About

Inter- and intramolecular isotopic correlations in some cyanogenic glycosides and glucosinolates and their practical importance

Cited by 18 publications

References 17 publications

A retro-biosynthetic approach to the prediction of biosynthetic pathways from position-specific isotope analysis as shown for tramadol

A retro-biosynthetic approach to the prediction of biosynthetic pathways from position-specific isotope analysis as shown for tramadol

Changes inδ13C of dark respired CO2and organic matter of different organs during early ontogeny in peanut plants

Carbon isotope ratios of amylose, amylopectin and mutant starches

Contact Info

Product

Resources

About

Changes inδ¹³C of dark respired CO₂and organic matter of different organs during early ontogeny in peanut plants