The molecular and crystal structure of D,L-4-methoxy-6-styryl-5,6-dihydro-α-pyrone (kavain)

Abstract

AuszugDie Kristallstruktur von Kavain C14H14O3, wurde röntgenographisch bestimmt. Die Kristalle sind monoklin mit α = 23,032 A, b = 9,430 A, c = 5,738 A und β = 104° 14', Ζ = 4, Raumgruppe P2i/o. Die Struktur wurde mit Hilfe der symbolischen Additionsmethode gelöst. Die Verfeinerung geschah durch Block-matrix-least-squares-Berechnungen einschließlich anisotroper Temperaturfaktoren. Der endgültige -R-Wert für die 1384 beobachteten Reflexe ist 0,076. AbstractThe crystal structure of kavain, CiiHuOa, has been determined by x-ray diffraction methods. The crystals are monoclinic with space group P2i/a. The unit-cell dimensions are a = 23.032 A, b = 9.430 A, c = 6.738 A and β = 104° 14'. There are four molecules in the unit cell. The structure was solved by the symbolic-addition method. The refinement was carried out by the block-matrix least-squares calculations including anisotropic temperature factors. The final R value for 1384 observed reflections was 0.076. IntroductionKava lactones and flavonoids which are extracted from the roots of pepper have a central myorelaxing effect. These kava lactones are unsaturated 6'-substituted pyrone compounds 1 . Of these kava lactones, kavain is the most effective; it is now synthesized in vitro.

Structural Characterization of Genuine (-)-Pipermethystine, (-)-Epoxypipermethystine, (+)-Dihydromethysticin and Yangonin from the Kava Plant (Piper methysticum)

“…Here, we were interested in structure characterization as a basis for investigating structure-activity relationships. The structural data of only four of about 20 known α-pyrone kavalactones, methysticin (M) [21], kavain (K) [22], dihydrokavain (DK) [23] and desmethoxyyangonin (DMY, also referred to as dehydrokavain) [24] have been reported in the 1970s, but remained elusive due to the unclear absolute configurations and high residuals (≥ 7%). The structural details of the unique PM skeleton are not yet known.…”