Magnolianin

Chem Pharm Bull (Tokyo). 2001 Jun;49(6):716-20.

Effects of constituents from the bark of Magnolia obovata on nitric oxide production in lipopolysaccharide-activated macrophages.[Pubmed: 11411523]

The methanolic extract from a Japanese herbal medicine, the bark of Magnolia obovata, was found to inhibit nitric oxide (NO) production in lipopolysaccharide (LPS)-activated macrophages.
METHODS AND RESULTS:
By bioassay-guided separation, three neolignans (magnolol, honokiol, obovatol) and three sesquiterpenes (alpha-eudesmol, beta-eudesmol, gamma-eudesmol) were obtained as active constituents. A trineolignan (Magnolianin), a phenylpropanoid glycoside (syringin), lignan glycosides (liriodendrin, (+)-syringaresinol 4'-O-beta-D-glucopyranoside) and a sesquiterpene (caryophyllene oxide) did not show any activity. On the other hand, sesquiterpene-neolignans (eudesmagnolol, clovanemagnolol, caryolanemagnolol, eudeshonokiol A, eudesobovatol A) showed the strong cytotoxic effects.
CONCLUSIONS:
Active constituents (magnolol, honokiol, obovatol) showed weak inhibition for inducible NO synthase (iNOS) enzyme activity, but potent inhibition of iNOS induction and activation of nuclear factor-kappaB.

Tetrahedron Letters, 1993 , 34 (6) :1051-1054.

Structure of Magnolianin, a novel trilignan possessing potent 5-lipoxygenase inhibitory activity[Reference: WebLink]

METHODS AND RESULTS:
Magnolianin, a novel trilignan with a 1, 4-benzodioxane ring, isolated from the bark of Magnolia obovata, has been assigned structure on the basis of extensive analysis of 2D 1H and 13C NMR of its triacetate derivative.
CONCLUSIONS:
Magnolianin has been found to inhibit strongly (IC50 = 0.45 μM) 5-HETE formation by die cytosol of guinea pig polymorphonuclear leukocytes.