Three new guaianolides, 10alpha-hydroxy-3-oxoguaia-4(15),11(13)-dieno-12,6alpha-lactone (1), 10alpha-hydroxy-3-oxo-4betaH-guaia-11(13)-eno-12,6alpha-lactone (2), and 10alpha-hydroxy-3-oxoguaia-4,11(13)-dieno-12,6alpha-lactone (3), named chinensiolides A, B, and C were isolated from the whole plant of Siyekucai (Ixeris chinensis). The structures were determined by HREIMS, UV, IR, and one- and two-dimensional NMR techniques ((1)H and (13)C NMR, COSY, HMQC, HMBC, and NOE difference and NOESY experiments). Compounds 1 and 2 were indicated to be a mixture of flexible conformers by analyses of their 1D NOE and NOESY spectra as well as the temperature dependence of their (1)H and (13)C NMR spectra. Chinensiolide B (2) was transformed to chinensiolide C (3) in a three-step conversion.
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http://dx.doi.org/10.1021/np0202632 | DOI Listing |
Nat Prod Res
May 2024
Université de Reims Champagne Ardenne, CNRS, ICMR, Reims, France.
Chemical investigation of the aerial parts of Maire led to the isolation and identification of one sesquiterpene lactone glucoside of the guaianolide type (dihydropseudoivalin-4---d-glucopyranoside), along with nine known compounds including one diterpenoid, two sesquiterpenoids, three lignanes and three flavonoids. Their structures were established on the basis of spectroscopic analysis. All these compounds were evaluated for their DPPH radical scavenging and tyrosinase inhibitory activities.
View Article and Find Full Text PDFOrg Lett
June 2024
Aristotle University of Thessaloniki, Department of Chemistry, Laboratory of Organic Chemistry, Thessaloniki 54124, Greece.
The divergent synthesis of a non-natural 8,12-sesquiterpenoid lactone collection is described. The synthesis relies on a rationally designed guaianolide scaffold bearing a tertiary hydroxyl as the pinpoint for inducing its selective diversification. Key reactions include an unprecedented Suarez-type CH lactonization and a highly diastereoselective oxy-Cope/ene cascade that allows the introduction of three stereocenters in a single operation.
View Article and Find Full Text PDFBioorg Med Chem Lett
May 2024
State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China. Electronic address:
Phytochemistry
April 2024
State Key Laboratory Basis of Xinjiang Indigenous Medicinal Plants Resource Utilization, and the Key Laboratory of Plant Resources and Chemistry of Arid Zone, Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi, 830011, China; University of the Chinese Academy of Sciences, Beijing, 100039, China. Electronic address:
Seven undescribed sesquiterpenes, including three dimeric guaianolide sesquiterpenes artemongolides G-I (1-3) and four sesquiterpene lactones artemanomalide D-G (16-19), along with seventeen known compounds isoabsinthin (4), absinthin (5), 11-eptabsinthin (6), 11, 11'-bis-epiabsinthin (7), 10', 11'- epiabsinthin (8), anabsinthin (9), isoanabsinthin (10), absinthin D (11), anabsin (12), caruifolin D (13), gnapholide (14), caruifolin C (15), 1β(R),10β(S)-dihydroxy-3-oxo-11β (S)H-4,11(13)-guaien-6α(S),12-olide (20), 1α,6α,8α-trihydroxy-5α,7βH-guaia-3,10(14),11(13)-trien-12-oic acid (21), 1α,6α,8α-trihydroxy-5α,7βH-guaia-3,9,11(13)-trien-12-oic acid (22), argyinolide J (23), artabsinolide A (24) were isolated from the plant Artemisia mongolica. The structures were determined by interpreting NMR, HRESIMS and ECD data. The X-ray crystal structure of 4, 7 and 8 were reported for the first time.
View Article and Find Full Text PDFChem Biodivers
March 2024
Instituto de Investigaciones para la Industria Química (INIQUI-CONICET), Universidad Nacional de Salta, Av. Bolivia 5150, 4400, Salta, Argentina.
Phytochemical study of the species Kaunia lasiophthalma enabled the isolation of three undescribed and three known guaianolide-type sesquiterpene lactones, and one new benzofuran. The bioguided fractionation methodology was successful in detecting antimicrobial metabolites against Staphylococcus aureus strains and permitted the description of undescribed guaianolide-type sesquiterpene lactones with substitution patterns matching all those described in the Oxylobinae subtribe.
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