Juncuenin D

Screening of Luzula species native to the Carpathian Basin for anti-inflammatory activity and bioactivity-guided isolation of compounds from Luzula luzuloides (Lam.) Dandy & Wilmott.[Pubmed:27940118]

Fitoterapia. 2017 Jan;116:131-138.

The present study focused on the anti-inflammatory screening of Luzula species native to the Carpathian Basin and bioactivity-guided isolation of compounds of Luzula luzuloides (Lam.) Dandy & Wilmott. The anti-inflammatory properties of extracts with different polarity prepared from Luzula species were determined. Among them, the CH2Cl2-soluble fraction of L. luzuloides possessed strong inhibitory effects on superoxide anion generation (99.39+/-0.37%) and elastase release (114.22+/-3.13%) in fMLP/CB-induced human neutrophils at concentration of 10mug/mL. From this fraction, six compounds (1-6) were isolated by the combination of different chromatographic methods. The structures of the compounds were determined by means of MS, 1D and 2D NMR spectroscopy. The results allowed the identification of the new 1,6-dihydroxy-2-keto-1,7-dimethyl-8-vinyl-1,2-dihydrophenanthrene (1) from the plant, named luzulin A. Chiral HPLC and HPLC-ECD analysis revealed that 1 possesses low enantiomeric excess and TDDFT-ECD calculations afforded the configurational assignment of the separated enantiomers. Three known phenanthrenes [juncuenin B (2), dehydrojuncuenin B (3) and juncusol (4)] and two flavonoids [apigenin (5) and luteolin (6)] were also isolated. The anti-inflammatory activity of the isolated compounds was tested and IC50 values were determined. This was the first time that phenanthrenes were detected in a Luzula species. The oxidative transformation of juncuenin B (3) led to the isolation of its possible biometabolites, namely luzulin A (1), dehydrojuncuenin B (4), and Juncuenin D (7). The isolated compounds (1-4) confirm that besides flavonoids, phenanthrenes could also serve as chemotaxonomic markers for Luzula species and prove the close relationship of Juncus and Luzula genus.

Phenanthrenes from Juncus inflexus with Antimicrobial Activity against Methicillin-Resistant Staphylococcus aureus.[Pubmed:27808510]

J Nat Prod. 2016 Nov 23;79(11):2814-2823.

The present study has focused on an investigation of the antibacterial effects of Juncus inflexus and the isolation and identification of its active compounds. Eleven phenanthrenes were isolated from a methanolic extract of the roots. Four compounds (jinflexins A-D, 1-4) are new natural products, while seven phenanthrenes [juncuenins A (5), B (6), and D (8), juncusol (7), dehydrojuncuenins A (9) and B (11), and dehydrojuncusol (10)] were isolated for the first time from the plant. Jinflexin D (4) is a dimer with an unprecedented heptacyclic ring system. The absolute configurations of the new compounds were determined by TDDFT-ECD calculations, and their enantiomeric purity was checked by chiral HPLC analysis. Extracts of different polarity (n-hexane, dichloromethane, and ethyl acetate) were evaluated for their antimicrobial effects against methicillin-resistant Staphylococcus aureus, extended-spectrum beta-lactamase (ESBL)-producing Citrobacter freundii, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, multiresistant Acinetobacter baumannii, and Pseudomonas aeruginosa. The MIC values of the isolated compounds were determined by a microdilution method. Jinflexin B (2), juncusol (7), Juncuenin D (8), and dehydrojuncuenin B (11) showed significant activity (MIC value range 12.5-100 mug/mL) against MRSA strains.

Antibacterial screening of Juncaceae species native to the Carpathian Basin against resistant strains and LC-MS investigation of phenanthrenes responsible for the effect.[Pubmed:27702667]

Fitoterapia. 2016 Dec;115:69-73.

The main objective of this project was to investigate the antibacterial activity of 19 species (Juncus acutus, J. alpinoarticulatus, J. articulatus, J. compressus, J. conglomeratus, J. effusus, J. filiformis, J. gerardii, J. inflexus, J. maritimus, J. monanthos, J. squarrosus, J. tenuis, J. trifidus, Luzula campestris, L. forsteri, L. luzuloides, L. sudetica and L. sylvatica) belonging to the family Juncaceae against methicillin-resistant S. aureus (MRSA), extended-spectrum beta-lactamase (ESBL)-producing C. freundii, E. coli, E. cloacae, K. pneumoniae, and multiresistant A. baumannii and P. aeruginosa. Antibacterial susceptibilities were screened for inhibitory zones and MIC values determined by microdilution method. Among the tested extracts (n=96) 16 extracts prepared from Juncus species and 3 extracts from Luzula species showed mild to strong inhibitory activities against MRSA strains (inhibition zones=6.7mm-14.6mm; MIC values 9.75-156mug/mL). It can be concluded that Juncus and Luzula species demonstrated promising anti-MRSA effect, and J. maritimus, J. tenuis and J. gerardii considered worthy of activity-guided phytochemical investigations. The main bioactive constituents of Juncaceae species are phenanthrenes. Four phenanthrenes [Juncuenin D (1), juncusol (2), dehydrojuncuenin B (3), and jinflexin B (4)] isolated previously from J. inflexus with anti-MRSA activity were investigated by LC-MS in extracts proved to be active in antimicrobial test.

[Phenanthrenes from aerial part of Juncus setchuensis with anxiolyticactivity].[Pubmed:28875672]

Zhongguo Zhong Yao Za Zhi. 2016 Mar;41(6):1070-1074.

Ten phenanthrenes, two organic acids, one organic acid ester and one flavonoid were isolated from the aerial part of Juncus setchuensis by various chromatographic techniques usingsilica gel, polyamide, Sephadex LH-20 as solid phases, and preparative HPLC. Their structures were identified by MS and NMR spectroscopic data as effusol(1), juncusol(2), Juncuenin D(3), dehydroeffusol(4), dehydrojuncusol(5), juncuenin B(6),dehydrojuncuenin B(7), 2-methoxyl-7-hydroxyl-1-methyl-5-vinyl phenanthrene(8), 2-hydroxyl-7-carboxy-1-methyl-5-vinyl-9,10-dihydrophenanthrene(9), 2-hydroxyl-7-carboxyl-1-methyl-5-vinylphenanthrene(10), luteolin(11), vanillic acid(12), daphnetin(13), p-coumaric acid(14), respectively. Compound 13 was isolated from the genus Juncus for the first time and compounds 5, 8-12 were isolated from J. setchuensis for the first time. The elevated plus-maze(EPM) was used to evaluate the anxiolytic activity of compounds 6 and 7. Compound 6 at 5 mg*kg(-)(1) and 10 mg*kg(-)(1) showed anxiolytic activity as well as compound 7 at 10 mg*kg(-)(1) and 20 mg*kg(-)(1).

Chemical constituents isolated from Juncus effusus induce cytotoxicity in HT22 cells.[Pubmed:25794817]

J Nat Med. 2015 Jul;69(3):421-6.

Effususol A (1), a new 9,10-dihydrophenanthrene, has been isolated from the medullae of Juncus effusus along with ten known compounds, effusol (2), dehydroeffusol (3), juncusol (4), dehydrojuncusol (5), juncuenin B (6), dehydrojuncuenin B (7), Juncuenin D (8), luteolin (9), luteolin 5-methyl ether (10), and 4-hydroxy-2,3-dimethyl-2-nonen-4-olide (11). The structure of 1 was elucidated on the basis of spectroscopic data. 2, 4, 6, 7, and 8 have induced caspase-3-mediated cytotoxicity in HT22 cells.