Abstract: Two new highly oxygenated limonoids, flexuosoids A(1) and B(2), and three new arylnaphthalene lignan glycosides, phyllanthusmins D-F(3-5), were isolated from the roots of Phyllanthus flexuosus, in addition to three known lignans, phyllanthusmin C, arabelline, and(+)-diasyringaresinol. Their structures were elucidated on the basis of detailed spectroscopic analysis and chemical methods. Compounds 1 and 2, two new decaoxygenated limonoids with a C-19/29 lactol bridge and heptaoxygenated substituents at C-1, C-2, C-3, C-7, C-11, C-17, and C-30, represent the second example of limonoids in the Euphorbiaceae family. Most of the isolates were tested for their antifeedant, anti-herpes simplex virus 1, and cytotoxic activities. The new limonoids 1 and 2 showed promising antifeedant activity against the beet army worm(Spodoptera exigua) with EC₅₀ values of 25.1 and 17.3 μg/cm², respectively. In addition, both of them displayed moderate cytotoxicity against the ECA109 human esophagus cancer cell line, along with the known lignan glycoside, phyllanthusmin C, with the IC₅₀ values of 11.5(1), 8.5(2), and 7.8(phyllanthusmin C) μM, respectively.

Key words: Phyllanthus flexuosus, Euphorbiaceae, Limonoids, Lignan glycosides, Antifeedant, Antiviral, Cytotoxicity

摘要： Two new highly oxygenated limonoids, flexuosoids A(1) and B(2), and three new arylnaphthalene lignan glycosides, phyllanthusmins D-F(3-5), were isolated from the roots of Phyllanthus flexuosus, in addition to three known lignans, phyllanthusmin C, arabelline, and(+)-diasyringaresinol. Their structures were elucidated on the basis of detailed spectroscopic analysis and chemical methods. Compounds 1 and 2, two new decaoxygenated limonoids with a C-19/29 lactol bridge and heptaoxygenated substituents at C-1, C-2, C-3, C-7, C-11, C-17, and C-30, represent the second example of limonoids in the Euphorbiaceae family. Most of the isolates were tested for their antifeedant, anti-herpes simplex virus 1, and cytotoxic activities. The new limonoids 1 and 2 showed promising antifeedant activity against the beet army worm(Spodoptera exigua) with EC₅₀ values of 25.1 and 17.3 μg/cm², respectively. In addition, both of them displayed moderate cytotoxicity against the ECA109 human esophagus cancer cell line, along with the known lignan glycoside, phyllanthusmin C, with the IC₅₀ values of 11.5(1), 8.5(2), and 7.8(phyllanthusmin C) μM, respectively.

关键词: Phyllanthus flexuosus, Euphorbiaceae, Limonoids, Lignan glycosides, Antifeedant, Antiviral, Cytotoxicity