Capsaicinoids: their separation, synthesis, and mutagenicity

Abstract

21 (26 mg, 39%) were separated by preparative TLC (C) and identified by comparison with authentic materials, prepared according to Le Men et al.26 X-ray Structure Determination. (A) Zwitterion 7a Hydrate (XR-1). Single crystals of XR-1 suitable for X-ray diffraction study were grown from a saturated MeOH solution. The structure was solved by direct methods (program multan so): the "best" E-map allowed to localize 27 heavy atoms over a total of 32. The remaining heavy atoms were located on a difference Fourier map. After isotropic refinement of heavy atoms, all hydrogen atoms, with the exclusion of those of solvation water, were located on a difference Fourier map. Hydrogen atoms at C(18) and C(25) gave problems in the least-squares process and then were fixed in calculated positions. Hydrogen atoms of solvated water were not clearly localized, because of the high thermal internal motion or the disorder of the same.(B) Isoxazolidine 8b Hydrobromide (XR-2). Single crystals of XR-2 were obtained by diffusion of diisopropyl ether into a saturated MeOH solution of 8b-HBr. The structure was solved

The Truth about False Unicorn (Chamaelirium luteum): Total Synthesis of 23R,24S‐Chiograsterol B Defines the Structure and Stereochemistry of the Major Saponins from this Medicinal Herb

“…Next, triphenylphosphine (100 mg, 0.4 mmol) was added and stirring was commenced. The ice bath was removed and after the mixture had returned to room temperature CH 2 Meanwhile, a solution of the required ylide was prepared as follows: Isobutyl phosphonium bromide [45] (36) (250 mg, 0.4 mmol) was suspended in diethyl ether (5 mL) and then butyllithium (0.23 mL, 1.4 m solution in hexanes, 0.32 mmol) was added dropwise with stirring at 25 8C. After complete addition, the deep-red solution was stirred for a further 30 min, before being cooled to À78 8C by using an external ice bath.…”

Enzymatic Synthesis of a Capsinoid by the Acylation of Vanillyl Alcohol with Fatty Acid Derivatives Catalyzed by Lipases

“…The acyl moiety of capsiate is an 8-methylnon-6-enoic acid, and that of dihydrocapsiate is an 8-methylnonanoic acid. The acyl donors can be produced by chemical synthesis, 29,30) although the process is complicated and the yield is low. Furthermore, commercial products are too expensive for application to practical use.…”

An Alternate Synthesis of the Capsaicinoids

“…3 ,6) la, b remained as oily substances, and their spectral data were essentially identical with those reported for nornorcapsaicin and norcapsaicin, respectively. 3) Ie has the same mass number as that of bishomocapsaicin which had been tentatively identified in Capsicum fruit extracts.…”