Caffeoylquinic acids are found in artichokes, and they are currently considered important therapeutic or preventive agents for treating Alzheimer's disease and diabetes. We transformed artichoke [the cultivated cardoon or Cynara cardunculus var. altilis DC (Asteraceae)] with the rolC gene, which is a known inducer of secondary metabolism. High-performance liquid chromatography with UV and high-resolution mass spectrometry (HPLC-UV-HRMS) revealed that the predominant metabolites synthesized in the transgenic calli were 1,5-dicaffeoylquinic acid, 3,4-dicaffeoylquinic acid, and chlorogenic acid. The rolC-transformed calli contained 1.5% caffeoylquinic acids by dry weight. The overall production of these metabolites was three times higher than that of the corresponding control calli. The enhancing effect of rolC remained stable over long-term cultivation.
Six iridoid derivatives (1-6), including two new compounds myrmecodoides A and B (1 and 2), were isolated from the ant-plant Myrmecodia tuberosa. Their structures were determined on the basis of spectroscopic data ((1)H and (13)C NMR, HSQC, HMBC, (1)H-(1)H COSY, NOESY and HR-ESI-MS) and by comparison with the literature values. Among isolates, 3 and 4 exhibit weak antibacterial effect against Staphylococcus aureus subsp. aureus with MIC value of 100.0 μg/mL.
Schizostachyum langbianense is a new woody bamboo from a high mountain, Lang Bian, in southern Vietnam, which is being described and illustrated. It is similar to S. ninhthuanense in having short ultimate inflorescence branchlets on which clusters of a few pseudospikelets are borne. However, it differs in its culm leaves with a horizontal or only slightly concave apical portion, culm leaf blades that are narrowly lanceolate, and a palea that is not apically bifid and dorsally sulcate with 2 keels. Both species occur in the same mountain region, but separated by distinct elevations.
Aralia hiepiana J.Wen & Lowry (Araliaceae), a new species from southern Vietnam, is described and illustrated by J. Wen & Lowry in 2002. Up to now, there are not any chemical data from this endemic species. By various chromatography methods, four flavonoids compounds namely kaempferol 3,7-O-α-L-dirhamnopyranoside (1), kaempferol 3-O-β-D-glucopyranosyl-7-O-a-L-rhamnopyranoside (2), kaempferol (3), quercetin (4), apigenin 7-O-β-glucopyranoside (5) were isolated from the methanol extract of leaves of Aralia hiepiana collected in Da Lat, Lam Dong province. Their structures were elucidated using 1-D and 2-D NMR techniques and by comparison with the literature data. This is the first time to isolate these compounds from Aralia hiepiana.
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