Two Novel Quassinoid Glycosides with Antiviral Activity from the Samara of Ailanthus altissima.

Phytochemistry investigations on Ailanthus altissima (Mill.) Swingle, a Simaroubaceae plant that is recognized as a traditional herbal medicine, have afforded various natural products, among which C20 quassinoid is the most attractive for their significant and diverse pharmacological and biological activities. Our continuous study has led to the isolation of two novel quassinoid glycosides, named chuglycosides J and K, together with fourteen known lignans from the samara of A. altissima. The new structures were elucidated based on comprehensive spectra data analysis. All of the compounds were evaluated for their anti-tobacco mosaic virus activity, among which chuglycosides J and K exhibited inhibitory effects against the virus multiplication with half maximal inhibitory concentration (IC50) values of 56.21 ± 1.86 and 137.74 ± 3.57 µM, respectively.

Anti-Tobacco Mosaic Virus Quassinoids from Ailanthus altissima (Mill.) Swingle.

Quassinoids are bitter constituents characteristic of the family Simaroubaceae. A total of 18 C20 quassinoids, including nine new quassinoid glycosides, named chuglycosides A-I (1-6 and 8-10), were identified from the samara of Ailanthus altissima (Mill.) Swingle. All of the quassinoids showed potent anti-tobacco mosaic virus (TMV) activity. A preliminary structure-anti-TMV activity relationship of quassinoids was discussed. The effects of three quassinoids, including chaparrinone (12), glaucarubinone (15), and ailanthone (16), on the accumulation of TMV coat protein (CP) were studied by western blot analysis. Ailanthone (16) was further investigated for its influence on TMV spread in the Nicotiana benthamiana plant.

Phenylpropionamides, Piperidine, and Phenolic Derivatives from the Fruit of Ailanthus altissima.

Four novel compounds-two phenylpropionamides, one piperidine, and one phenolic derivatives-were isolated and identified from the fruit of a medicinal plant, Ailanthus altissima (Mill.) Swingle (Simaroubaceae), together with one known phenylpropionamide, 13 known phenols, and 10 flavonoids. The structures of the new compounds were elucidated as 2-hydroxy-N-[(2-O-ß-d-glucopyranosyl)phenyl]propionamide (1), 2-hydroxy-N-[(2-O-ß-d-glucopyranosyl-(1→6)-ß-d-glucopyranosyl)phenyl]propionamide (2), 2ß-carboxyl-piperidine-4ß-acetic acid methyl ester (4), and 4-hydroxyphenyl-1-O-[6-(hydrogen-3-hydroxy-3-methylpentanedioate)]-ß-d-glucopyranoside (5) based on spectroscopic analysis. All the isolated compounds were evaluated for their inhibitory activity against Tobacco mosaic virus (TMV) using the leaf-disc method. Among the compounds isolated, arbutin (6), ß-d-glucopyranosyl-(1→6)-arbutin (7), 4-methoxyphenylacetic acid (10), and corilagin (18) showed moderate inhibition against TMV with IC50 values of 0.49, 0.51, 0.27, and 0.45 mM, respectively.

A New Erythrinan Alkaloid Glycoside from the Seeds of Erythrina crista-galli.

A new Erythrina alkaloid glycoside, named erythraline-11ß-O-glucopyranoside, was isolated from the seeds of Erythrina crista-galli L., together with five known Erythrina alkaloids and an indole alkaloid. The structure of the new alkaloid glycoside was elucidated by spectroscopic methods, and all of the compounds were evaluated for their antiviral activity against tobacco mosaic virus.