Structure of Precarthamin, a Biosynthetic Precursor of Carthamin

Hydroxyespintanol and schefflerichalcone: two new compounds from Uvaria scheffleri

“…Two very lowfield carbons (d C 191.0 and 196.8) seem to be attributable to carbonyl carbons. These results do not agree with a usual benzene ring structure, and these peculiar spectral properties can be explained in terms of b-triketone type compounds such as quinochalcones from Carthamus tinctorius L. [6][7][8] and a few others, e.g. champanones from Campomanesia lineatifolia [9], and grandiflorone from Leptospermum flavescens [10].…”

“…By a combination of column chromatography, preparative HPLC and preparative TLC, two new compounds, named hydroxyespintanol (1) and schefflerichalcone (2), were isolated along with eight known compounds (3)(4)(5)(6)(7)(8)(9)(10).…”

Total Synthesis of Carthamin, a Traditional Natural Red Pigment

“…The identity of the synthetic material 3 was verified by thorough analyses of the physical data ( 1 H and 13 C NMR, IR, CD, HRMS, HPLC). However, the identification process required a careful consideration of analytical conditions ,. Of particular note is comparison of the NMR spectra of the synthetic material 3 and the natural sample.…”

Synthetic Study of Carthamin: Biomimetic Synthesis of Carthamin Model via Peroxidase‐Catalyzed Oxidative Decarboxylation of Its Precursor Model

“…Structure determination of 2 was achieved 15 years after the structure determination of 1 due to its instability . A precursor model in which two glucose moieties were displaced by methyl groups was synthesized by us , but the natural chiral carthamin precursor ( 2 ) was still not synthesized.…”