Eight new arnebinol B-based meroterpenoids with planar chirality in the constrained 6/10/5 tricyclic skeleton from Arnebia euchroma and their cytotoxicities

Liao, 2020, Two new dimeric naphthoquinones from Arnebia euchroma, Phytochem. Lett., 37, 106, 10.1016/j.phytol.2020.04.004 Kumar, 2021, Phytochemical constituents, distributions and traditional usages of Arnebia euchroma: A review, J. Ethnopharmacol., 271, 113896, 10.1016/j.jep.2021.113896 Nasiri, 2016, The effects of Arnebia euchroma ointment on second-degree burn wounds: A randomized clinical trial, J. Ethnopharmacol., 189, 107, 10.1016/j.jep.2016.05.029 Malik, 2015, Ethnomedicinal plants traditionally used in health care practices by inhabitants of Western Himalaya, J. Ethnopharmacol., 172, 133, 10.1016/j.jep.2015.06.002 Singh, 2015, Antibacterial effect of butyryl alkannin from Arnebia euchroma against vancomycin-resistant pathogens of Enterococcus faecalis causing urinary tract infections, Nat. Prod. Res., 29, 2299, 10.1080/14786419.2015.1004676 Subbaramaiah, 2001, Development and use of a gene promoter-based screen to identify novel inhibitors of cyclooxygenase-2 transcription, J. Biomol. Screen, 6, 101, 10.1177/108705710100600206 Tariq, 2017, A systematic review on ethnomedicines of anti-cancer plants, Phytother. Res., 31, 202, 10.1002/ptr.5751 Kim, 2001, Antitumor activities of a newly synthesized shikonin derivative, 2-hyim-DMNQ-S-33, Canc. Lett., 172, 171, 10.1016/S0304-3835(01)00665-6 Shen, 2002, Antimicrobial activities of naphthazarins from Arnebia euchroma, J. Nat. Prod., 65, 1857, 10.1021/np010599w Damianakos, 2012, Antimicrobial and cytotoxic isohexenylnaphthazarins from Arnebia euchroma (Royle) Jonst. (Boraginaceae) callus and cell suspension culture, Molecules, 17, 14310, 10.3390/molecules171214310 Liu, 2010, Three new compounds from Arnebia euchroma, J. Asian Nat. Prod. Res., 12, 286, 10.1080/10286021003743861 Papageorgiou, 1999, The chemistry and biology of alkannin, shikonin, and related naphthazarin natural products, Angew. Chem. Int. Ed., 38, 270, 10.1002/(SICI)1521-3773(19990201)38:3<270::AID-ANIE270>3.0.CO;2-0 Q. Mu, J. Ye, Z.L. Sun, S. Jibens, M. Reheman, Natural naphthoquinone dimer and its use in preparation of antimicrobial drug, 2015, CN104887677 A [P]. Cao, 2020, Identification, in vitro evaluation and modeling studies of the constituents from the roots of Arnebia euchroma for antitumor activity and STAT3 inhibition, Bioorg. Chem., 96, 10.1016/j.bioorg.2020.103655 Yao, 1991, Biologically active constituents of Arnebia euchroma: structure of arnebinol, an ansa-type monoterpenylbenzenoid with inhibitory activity on prostaglandin biosynthesis, Chem. Pharm. Bull., 39, 2956, 10.1248/cpb.39.2956 Li, 2012, Compounds from Arnebia euchroma and their related anti-HCV and antibacterial activities, Planta Med., 78, 39, 10.1055/s-0031-1280266 Wang, 2015, Meroterpenoids and a naphthoquinone from Arnebia euchroma and their cytotoxic activity, Planta Med., 81, 320, 10.1055/s-0035-1545693 Wang, 2018, Meroterpenoids isolated from Arnebia euchroma (Royle) Johnst. and their cytotoxic activity in human hepatocellular carcinoma cells, Fitoterapia, 131, 236, 10.1016/j.fitote.2018.11.005 Yan, 2020, Archromones A-F, unusual polycyclic dearomatic geranylquinol derivatives from the roots of Arnebia euchroma, Org. Biomol. Chem., 18, 8424, 10.1039/D0OB01934H D.F. Chen, H.W. Zhu, G.X. Li, Benzoquinone compound and its application in preparing antitumor drug, 2013, CN103113335 A [P]. Yan, 2021, Photoinduced irreversible intramolecular proton transfer of arnebinones B, D, and E: the case of photoenolization at the p-benzoquinone-CH2/CH-π system, J. Nat. Prod., 84, 2981, 10.1021/acs.jnatprod.1c00830 Lv, 2014, Total synthesis of (±)​-​clavilactones A, B, and proposed D through iron-​catalyzed carbonylation-​peroxidation of olefin, Angew. Chem. Int. Ed., 53, 4164, 10.1002/anie.201400326 Arnone, 1994, Secondary mould metabolites. part 47. Isolation and structure elucidation of clavilactones A-C, new metabolites from the fungus Clitocybe clavipes, J. Chem. Soc., Perkin Trans., I, 2165, 10.1039/P19940002165 Merlini, 2000, Structure elucidation of clavilactone D: an inhibitor of protein tyrosine kinases, Phytochemistry, 53, 1039, 10.1016/S0031-9422(99)00506-3 Yoshimitsu, 2009, Studies of the asymmetric total synthesis of clavilactone D by the ‘Lariat’ cyclization strategy, Synthesis, 2009, 2963, 10.1055/s-0029-1216909 G.X. Ma, X.W. Huo, X.D. Xu, Z.C. Sun, Z.Y. Li, Nitrogen-containing heterocyclic mixed-source terpene, its isolation method and application, 2019, CN 110483540 A [P]. Takao, 2018, Total synthesis of clavilactones, J. Org. Chem., 83, 7060, 10.1021/acs.joc.7b03268 Nubbemeyer, 2001, Planar chirality-synthesis and transformations of 8- to 10-membered heterocycles bearing (E)-Olefins, Eur. J. Org. Chem., 10, 1801, 10.1002/1099-0690(200105)2001:10<1801::AID-EJOC1801>3.0.CO;2-D Deiters, 2000, Asymmetric synthesis of a (2Z, 7E)-cyclononadiene by an intramolecular cycloalkylation and insight to its conformational properties, Org. Lett., 2, 2415, 10.1021/ol005998h Testa, 2013, Organic Stereochemistry, Other stereogenic elements: axes of chirality, planes of chirality, helicity, and (E, Z)-diastereoisomerism, Helv. Chim. Acta, 96, 351, 10.1002/hlca.201200471 Xu, 2016, Bioactive sesquiterpenoid and polyacetylene glycosides from Atractylodes lancea, J. Nat. Prod., 79, 1567, 10.1021/acs.jnatprod.6b00066 Hu, 2019, Construction and optimization of microbial cell factories for sustainable production of bioactive dammarenediol-II glucosides, Green Chem., 21, 3286, 10.1039/C8GC04066D Wu, 2021, Sinucrassins A-K, casbane-type diterpenoids from the south China sea soft coral Sinularia crassa, Chinese J. Chem., 39, 2367, 10.1002/cjoc.202100253