A chemical investigation of the EtOAc-soluble fraction from the ethanol extract of the medullae of Juncus effusus led to the isolation of three new 9,10-dihydrophenanthrenes, juncuenins E-G (1-3); two new phenanthrenes, dehydrojuncuenins D-E (4-5); one new feruloylated glycoside (6); and one known 9,10-dihydrophenanthrene (7). The structures of these compounds were determined by analyzing their spectroscopic data. Metabolites 1-4 and 7 were further evaluated for their in vitro cytotoxic activities against seven human cancer lines (A549, MCF-7, BEL-7402, HeLa, COLO205, BGC-823, and SK-OV-3). Among them, compound 1 exhibited weak cytotoxicity against MCF-7 and HeLa cell lines. Compound 7 showed moderate cytotoxicity against MCF-7 and HeLa cell lines, with IC50 values of 9.17 and 19.6 µM, respectively.

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The synthesis of Yanglingmycin and its enantiomer, along with eighteen Yanglingmycin analogues is reported. The structures were confirmed mainly by analyses of NMR spectral data. Antibacterial activity assays showed that Yanglingmycin and some of its analogues exhibited significant antibacterial activities against two important agricultural pathogenic bacteria, Ralstonia solanacearum and Pseudomonas syringae pv. actinidiae, with minimum inhibitory concentration (MIC) values ranging from 3.91 to 15.62 µg/mL. The antibacterial activities exhibited by Yanglingmycin and its analogues are promising, suggesting potential in the development of compounds for novel bactericides.Key words Yanglingmycin; structural analogue; substituted cyclic azole; antibacterial activity Bacterial diseases pose a major threat to agricultural production worldwide. For example, Ralstonia solanacearum, which causes plant bacterial wilt, is one of the most destructive plant pathogens, and affects many regions of the world. 1)It is estimated that R. solanacearum is responsible for US$ 1 billion in losses each year.2) Pseudomonas syringae pv. actinidiae, which causes kiwifruit canker, is another devastating plant pathogen and has received significant attention in recent years.3-6) Thus, there has been considerable interest in development of bactericides for Ralstonia solanacearum and Pseudomonas syringae pv. actinidiae. Unfortunately, there have been few reports of effective bactericides against these pathogens. In the process of screening new agricultural antibiotics, we report the synthesis a new broad spectrum antibiotic, Yanglingmycin (Fig. 1), which was found to be effective against the previously mentioned pathogens. 7) Although Yanglingmycin can be isolated from the fermentation broth of Streptomyces djakartensis, the yield is too low to conduct experiments to determine the mechanism of bactericidal action. In order to investigate the bactericidal activities of Yanglingmycin and its analogues, Yanglingmycin and its analogues were designed and synthesized. In this paper, Yanglingmycin and its enantiomer and eighteen Yanglingmycin analogues were synthesized and their antibacterial activities against Ralstonia solanacearum and Pseudomonas syringae pv. actinidiae are reported. ResultsChemistry Chart 1 describes the synthesis of all target compounds. Benzonitrile, 2-hydroxybenzonitrile, and 4-hydroxybenzonitrile were used as starting material for the Pinner reaction to obtain the corresponding methyl benzimidate hydrochlorides, 8) which were then reacted with each the following compounds: L-serine methyl ester hydrochloride, D-serine methyl ester hydrochloride, L-cysteine methyl ester hydrochloride, D-cysteine methyl ester hydrochloride, L-2,3-diaminopropionic acid methyl ester hydrochloride, and D-2,3-diaminopropionic acid methyl ester hydrochloride.9,10) Amino acid methyl ester hydrochlorides were obtained by reacting the corresponding amino acids with AcCl in MeOH.11) The products were reduced by LiAlH 4 to obtain Yanglingmycin and its an...

From the whole plant of Spiranthes sinensis, one novel dimeric phenanthrene, 2,2'-dihydroxy-5,5',7,7'-tetramethoxy-9,9',10,10'-tetrahydro-3,3'-biphenanthrene (1) and flavone 5-hydroxy-3,7-dimethoxy-4'-(1-hydroxy-3-methylbut-3-en-2-yloxy)-flavone (2) were isolated along with three other known flavonoids, which are reported for the first time from this species. Their structures were established after an extensive analysis by 1D and 2D NMR spectroscopy (NOESY, HSQC, and HMBC) as well as HR-TOF-MS.