Two new compounds named fischeacid and fischexanthone, together with eight known compounds, were obtained from the culture of a marine-derived fungus Neosartorya fischeri strain 1008F₁. The structures of the new compounds were elucidated based on the spectroscopic data. Bioassays indicated that AGI-B4 and 3,4-dihydroxybenzoic acid showed potent inhibitory effect on the replication of tobacco mosaic virus, and AGI-B4 also possessed an inhibition of the cell proliferation of human gastric cancer cell line SGC-7901 and hepatic cancer cells BEL-7404.

Two new compounds, asperxanthone and asperbiphenyl, were identified as active components from Aspergillus sp. (MF-93).

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-β-d-glucopyranosyl)phenyl]propionamide (1), 2-hydroxy-N-[(2-O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl)phenyl]propionamide (2), 2β-carboxyl-piperidine-4β-acetic acid methyl ester (4), and 4-hydroxyphenyl-1-O-[6-(hydrogen-3-hydroxy-3-methylpentanedioate)]-β-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), β-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.

No abstract

Quassinoids are bitter constituents characteristic of the family Simaroubaceae. A total of 18 C 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.

Plant-associated microorganisms are known to produce a variety of metabolites with novel structures and interesting biological activities. An endophytic fungus FJBJ11, isolated from the plant tissue of Brucea javanica (L.) Merr. (Simaroubaceae), was proven to be significantly effective in producing metabolites with anti-Tobacco mosaic virus (TMV) activities. The isolate was identified as Aspergillus tubingensis FJBJ11 based on morphological characteristics and ITS sequence. Bioassay-guided isolation led to the identification of a cycli penta-peptide, malformin A1, along with two cyclic dipeptides, cyclo (Gly-l-Pro) and cyclo (Ala-Leu). Malformin A1 showed potent inhibitory effect against the infection and replication of TMV with IC50 values of 19.7 and 45.4 μg·mL−1, as tested using local lesion assay and leaf-disc method, respectively. The results indicated the potential use of malformin A1 as a leading compound or a promising candidate of new viricide.

The fermentation and isolation of metabolites produced by an endophytic fungus, which was identified as Phomopsis sp. FJBR-11, based on phylogenetic analysis, led to the identification of six compounds, including dothiorelones A–C, and H, and cytosporones C and U. Among these compounds, cytosporone U exhibited potent inhibitory activity against Tobacco mosaic virus (TMV). Moreover, the crude and a purified exopolysaccharide were proved to possess strong inhibitory effects against the virus infection.

Three new ursane triterpenes, 3α,19α-dihydroxy-2-nor-urs-12-en-23,28-dioic acid-23-methyl ester (1), 19α3-dihydroxy-3-oxo-2-nor-urs-12-en-28-oic acid (2), and 2,3-seco-3-methoxy-3,19α3-trihydroxy-urs-12-en-2-al-28-oic acid (3), were isolated from the MeOH extract of the branch barks of Davidia involucrata, together with six known compounds. Their structures were elucidated by means of various spectroscopic analyses. The isolated triterpenes provide important evolutionary and chemotaxonomic knowledge about the monotypic genus Davidia. Five of the identified compounds showed moderate cytotoxicities against the cell proliferation of SGC-7901, MCF-7, and BEL-7404 with IC 50 range from 7.26 to 47.41 μM.