Constituents of the stem barks of Ailanthus altissima and their anti-inflammatory activity

The stem barks of Ailanthus altissima Swingle (Simaroubaceae) have been used in traditional herbal medicine as an astringent, antispasmodic, anthelmintic, parasiticide and narcotic in North East Asia [1]. Previous investigations of A. altissima revealed the presence of alkaloids, quassinoids, terpenoids, steroids and flavonoids, among others [2]. The antioxidant, antimalarial, antiviral, antifungal, insecticidal, antituberculosis, anti-inflammatory, cytotoxic, antiproliferative and antiasthmatic activities have previously been reported for A. altissima [3]. Especially, alkaloids from A. altissima are known for their antiherpes and antimycotic properties and for their action on the rate of intestinal blood flow in rabbit [4]. As a part of our ongoing project to search novel secondary metabolites from medicinal plants, we chose the stem barks of A. altissima for detailed phytochemical study. Repeated chromatography of the EtOAc- and BuOH-soluble fractions from the stem barks of A. altissima led to the isolation of a new canthinone type alkaloid, (R)-5-(1-hydroxyethyl)-canthine-6-one (1), together with fourteen known compounds, including five alkaloids (2-6), four phenyl propanoids (7-10), two lignans (11 and 12), two triterpenoids (13 and 14) and a fatty acid (15). The structure of new compound was elucidated by physical (mp, [α] _D) and spectroscopic data (¹H NMR, ¹³C NMR, 2D NMR, and HR-DART-MS) interpretation and its absolute configuration was determined by electronic circular dichroism (ECD) data and quantum chemical calculations. To our knowledge, this is the first report on the isolation of known compounds 3-9 and 12 from A. altissima. The inflammatory activities of the 15 isolates were screened on LPS-induced nitric oxide (NO), a proinflammatory mediator, in RAW 264.7 cells. Among these isolated compounds, six compounds (1, 2, 4, 5 and 9) exhibited significant inhibition of NO production, with IC₅₀ values in the range of 5.92 ± 0.9 to 15.09 ± 1.8µM.

Acknowledgements: This work was supported by the Bio-Synergy Research Project (NRF-2014M3A9C4066594) of the Ministry of Science, ICT, and Future Planning through the National Research Foundation and High Value-added Food Technology Development Program, Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, Forestry, and Fisheries (113036 – 04 – 1-HD020).

Keywords: Ailanthus altissima, simaroubaveae, canthinone type alkaloids, nitric oxide, inflammation.

References:

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