Isoindolines and phthalides from the rhizomes of Ligusticum chuanxiong and their relaxant effects on the uterine smooth muscle.

Three undescribed isoindoline alkaloids, (+)-(R)-3-butyl-3-ethoxyisoindolin-1-one, (+)-(3S,6S,7R)-3-butyl-6,7-dihydroxy-3-methoxy-4,5,6,7-tetrahydroisoindolin-1-one, and (-)-(3R,6S,7R)-3-butyl-6,7-dihydroxy-3-methoxy-4,5,6,7-tetrahydroisoindolin-1-one, along with nine known phthalides were isolated from a water decoction of the rhizomes of Ligusticum chuanxiong using chromatographic methods. Their structures and absolute configurations were determined by extensive spectroscopic analyses and ECD data calculations. The relaxant effects of the isolated compounds on uterine contractions induced by oxytocin were investigated using a rat uterine smooth muscle contraction model. Furthermore, the effects of riligustilide on extracellular Ca2+ influx and intracellular Ca2+ release were assessed using high-KCl solution-induced and oxytocin-induced uterine smooth muscle contraction in a Ca2+-free balanced salt solution. The results showed that all the tested phthalides had inhibitory effects on oxytocin-induced uterine smooth muscle contraction. Riligustilide, a phthalide dimer, was the most active. Further examinations indicated that riligustilide reduced uterine smooth muscle contraction by inhibiting extracellular Ca2+ influx and intracellular Ca2+ release.

Bis-spirolabdane diterpenoids from Leonurus japonicus and their anti-platelet aggregative activity.

Six bis-spirolabdane diterpenoids along with four known analogues were isolated from the aerial parts of Leonurus japonicus. Their structures and absolute configurations were elucidated by spectroscopic analyses, single-crystal X-ray diffraction, and a modified Mosher's method. The inhibitory activity of the compounds against the abnormal increase in platelet aggregation induced by adenosine diphosphate was investigated. Only the (13R)-bis-spirolabdane diterpenoids exhibited a significant effect.

[Coumarins from Leonurus japonicus and their anti-platelet aggregative activity].

Chemical constituents of Leonurus japonicus were isolated and purified by a combination of various chromatographic techniques including column chromatography over silica gel, Sephadex LH-20, MCI, and Rp C18. Structures of the isolates were determined by spectroscopic analysis as 10 coumarins: bergapten (1), xanthotoxin (2), isopimpinellin (3), isogosferal (4), imperatorin (5), meransin hydrate(6), isomeranzin(7), murrayone(8) , auraptenol(9), and osthol(10). In addition to compound 9, the others were isolated from the genus Leonurus for the first time. In the in vitro assay, compounds 4 and 8 significantly inhibited the abnormal increase of platelet aggregation induced by ADP.