Synthesis of [³H]‐labelled glucobrassicin, a potential radiotracer for metabolic studies of indole glucosinolates

Abstract

Glucobrassicin, an indole glucosinolate widespread in cruciferous plants, appears to be involved in anticarcinogenic activity via its breakdown products. In order to study the "in vivo" metabolism of glucobrassicin. we have synthesized the 5-[3H]-indol-3-ylmethyl glucosinolate (3H-labelled glucobrassicin) starting from artificial peracetylated 5-bromoindol-3-ylmethyl glucosinolate. The labelled compounds were characterized by radio-HPLC and FAB mass spectrometry.

Gut Glucosinolate Metabolism and Isothiocyanate Production

“…Other radiolabelled GSLs and stable isotopically labelled GSLs have also been synthesized which also would be useful in GSL metabolism studies. [63,64]…”

“…With the known synthesis of [10‐ 13 C,11,12‐ 2 H 5 ]glucoraphanin it is surprising that this GSL has not been utilized in metabolism work with humans or animal models where there could be scope for in vivo NMR spectroscopy. Other radiolabelled GSLs and stable isotopically labelled GSLs have also been synthesized which also would be useful in GSL metabolism studies …”

Tritium-labelled alkaloids: Synthesis and applications

“…We have also tritiated the physostigmine phenyl analogue phenserine ( 2 ) using a halogenation‐catalytic tritium dehalogenation approach, demonstrating the position of tritium installation by both tritium and proton nuclear magnetic resonance (NMR) . The indole glucosinolate glucobrassicin, prevalent in most cruciferous plants, was also radiolabelled by means of a bromination‐catalytic tritium dehalogenation procedure to study its metabolism …”

“…10 The indole glucosinolate glucobrassicin, prevalent in most cruciferous plants, was also radiolabelled by means of a bromination-catalytic tritium dehalogenation procedure to study its metabolism. 11 The roots of Catharanthus roseus are the source of biologically active indole alkaloid ajmalicine and structurally related analogues like serpentine (3). So that the biosynthetic interconnection of this alkaloid family can be further understood, serpentine was converted to [ 3 H]ajmalicine (4) by reduction with sodium borotritide.…”

The synthesis and enzymic hydrolysis of (E)-2-[2,3-2H2]propenyl glucosinolate: Confirmation of the rearrangement of the thiohydroximate moiety

“…These labelled glucosinolates have included 14 C-phenethyl glucosinolate (gluconasturtiin) (Svanem et al, 1997), 3 H-butenyl glucosinolate (gluconapin) (Rossiter and James, 1990), 3 H-indolyl glucosinolate (glucobrassicin) (Chevolleau et al, 1993) and 2 H-phenethyl glucosinolate (Morrison and Botting, 2005). The synthesis of labelled glucosinolates can give high specific activities as compared to feeding plants with radiolabelled amino acids, which can require extensive purification steps (Chen and Halkier, 2000).…”