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6. Challenge and prospect
Natural products (NPs) have been increasingly attracting attention from various fields due to their structural diversity and biological activities.[13] The skeletal types of NPs are closely related to their biological evolution. As the evolution progresses, organisms must continuously change their biosynthetic pathways to adapt the change in the various environment or resist external threats, which result in changes in the skeletal types of NPs. This relationship between NPs structure and evolution makes NPs an important area in the fields of chemistry and biology.[167]
The discovery of new carbon skeletons in NPs is often accompanied by the discovery of new biological activities. For example, the famous sesquiterpenoid artemisinin and diterpenoid taxol show notable antimalarial and antitumor activities respectively, which highlights the significance of the discovery of novel skeletal NPs and their potential impact on the development of new drugs.
However, the quantity of novel skeletal NPs is generally limited, makeing it difficult to evaluate the biological activities of novel skeleton compounds,[168] which might limit the potential of NPs or hinder the development of new drugs based on these compounds. Therefore, these challenges may inspire strong interests among organic chemists, biologists, and pharmacologists. As terpenoids are one of the largest classes of NPs, this review focuses on 166 natural terpenoids with intriging structures from 2017−2022, including the isolation, structural determination, plausible biosynthetic pathways, and biological activities. Hopefully, this review would provide a new perspective for the scholars who are interested in NPs.
References
[1] Medicinal Natural Products: a biosynthetic approaach , Ed.: Dewick, P. M.; John Wiley & Sons, Chichester, 2009 .
[2] Zhao, H.; Sun, L.; Kong, C.; Mei, W.; Dai, H.; Xu, F.; Huang, S. Phytochemical and pharmacological review of diterpenoids from the genusEuphorbia Linn(2012–2021). J. Ethnopharmacol . 2022 , 298, 115574.
[3] Zhan, Z. J.; Li, S.; Chu, W.; Yin, S. Euphorbia diterpenoids: isolation, structure, bioactivity, biosynthesis, and synthesis (2013–2021). Nat. Prod. Rep. 2022 , 39, 2132–2174.
[4] Hu, L.; Wang, Z.; Tong, Z.; Hu, P.; Kong, L.; Luo, M.; Li, X. N.; Zhang, Y.; Huang Z.; Zhang, Y. Undescribed Meroterpenoids fromHypericum japonicum with Neuroprotective Effects on H2O2 Insult SH-SY5Y Cells Targeting Keap1-Nrf2. Chin. J. Chem. 2022 , 40, 1321–1330.
[5] Liu, M.; Zhang, X.; Shen, L.; Lin, S.; Ye, Y.; Qi, C.; Wang, J.; Hu, Z.; Zhang, Y.; Meroterpenoids with Potent Immunosuppressive Activity from Fungus Bipolaris zeicola . Chin. J. Chem.2021 , 39, 2460–2466.
[6] Zhang, Y. Y.; Yan, Y.; Zhang, J.; Xia, C. Y.; Lian, W. W.; Wang, W. P.; He, J.; Zhang, W. K.; Xu, J. K. Jolkinolide B: A comprehensive review of its physicochemical properties, analytical methods, synthesis and pharmacological activity. Phytochemistry . 2022 , 204, 113448.
[7] Huang, J. W.; Li, C. J.; Yang, J. Z.; Li, C.; Zhang, Y.; Liu, K.; Yu, Y.; Jiang, J. D.; Zhang, D. M. Guajamers A−I, Rearranged Polycyclic Phloroglucinol Meroterpenoids from Psidium guajavaLeaves and Their Antibacterial Activity. Chin. J. Chem.2021 , 39, 1129–1137.
[8] Chen, F.; Wang, J.; Luo, Y.; Li, C.; Huang, J.; Ma, J.; Zhang, D. Characteristic Dihydroagarofuran Sesquiterpenoids with Neuroprotective Effects from the Celastraceae Plant Tripterygium wilfordii . Chin. J. Chem. 2021 , 39, 2547–2554.
[9] Cheng, X.; Micalizio, G. C.; Synthesis of Neurotrophic Seco-prezizaane Sesquiterpenes (1R,10S)-2-Oxo-3,4-dehydroneomajucin, (2S)-Hydroxy-3,4-dehydroneomajucin, and (-)-Jiadifenin. J. Am. Chem. Soc. 2016 , 138, 1150–1153.
[10] Dong, S.; Lin, B; Xue, X.; Bai, M.; Huang, X.; Song, S. Discovery of β‐Dihydroagarofuran‐Type Sesquiterpenoids from the Leaves of Tripterygium wilfordii with Neuroprotective Activities.Chin. J. Chem. 2021 , 39, 337–344.
[11] Fraga, B. M. Natural sesquiterpenoids. Nat. Prod. Rep.2012 , 29, 1334–1366.
[12] Fraga, B. M. Natural sesquiterpenoids. Nat. Prod. Rep.2013 , 30, 1226–1264.
[13] Newman D. J.; Cragg, G. M. Natural Products as Sources of New Drugs from 1981 to 2014. J. Nat. Prod. 2016 , 79, 629–661.
[14] Wang, G. K.; Zhang, N.; Yao, J. N.; Yu, Y.; Wang, G.; Hung, C. C.; Cheng, Y. Y.; S. L. Morris-Natschke, S. L.; Zhou, Z. Y.; Liu, J. S.; Lee, K. H. Kalshinoids A–F, Anti-inflammatory Sesquiterpenes fromKalimeris shimadae . J. Nat. Prod. 2019 , 82, 3372–3378.
[15] Zhan, Z. C.; Wu, Z. N.; Tang, Q.; Li, C. J.; Wang, W. Z.; Zhang, J. H.; Zhuo, X. F.; Zhang, Y. B.; Wang, G. C.; Li, Y. L. Sesquiterpenoids from the Whole Plants of Chloranthus holostegiusand Their Anti-inflammatory Activities, Chin. J. Chem.2021 , 39, 1168–1174.
[16] Yokoyama, R.; Huang, J.; Yang, C.; Fukuyama, Y. New seco-Prezizaane-Type Sesquiterpenes, Jiadifenin with Neurotrophic Activity and 1,2-Dehydroneomajucin from Illicium jiadifengpi .J. Nat. Prod. 2002 , 65, 527–531.
[17] Huang, J.; Yokoyama, R.; Yang, C.; Fukuyama, Y. Structure and Neurotrophic Activity of seco-Prezizaane-Type Sesquiterpenes fromIllicium merrillianum . J. Nat. Prod. 2001 , 64, 428–431.
[18] Liu, J. F.; Wang, L.; Wang, Y. F.; Song, X.; Yang L. J.;. Zhang, Y. B. Sesquiterpenes from the fruits of Illicium jiadifengpi and their anti-hepatitis B virus activities,Fitoterapia , 2015 , 104, 41–44.
[19] Kubo, M.; Okada, C.; Huang, J.; Harada, K.; Hioki, H.; Fukuyama, Y. Novel Pentacyclic seco-Prezizaane-Type Sesquiterpenoids with Neurotrophic Properties from Illicium jiadifengpi .Org. Lett. 2009 , 11, 5190–5193.
[20] Zhu, Q.; Tang, C.; Ke, C.; Wang, W.; Zhang, H.; Ye, Y. Sesquiterpenoids and Phenylpropanoids from Pericarps of Illicium oligandrum . J. Nat. Prod. 2009 , 72, 238–242.
[21] Ma, S. G.; Li, M.; Lin, M. B.; Li, L.; Liu, Y. B.; Qu, J.; Li, Y.; Wang, X. J.; Wang, R. B.; Xu, S.; Hou, Q.; Yu, S. S. Illisimonin A, a Caged Sesquiterpenoid with a Tricyclo[5.2.1.01,6]decane Skeleton from the Fruits of Illicium simonsii . Org. Lett. 2017 , 19, 6160–6163.
[22] Yong, J. Y.; Li, W. R.; Wang, X. J.; Su, G. Z.; Li, M.; Zhang, J. P.; Jia, H. L.; Li, Y. H.; Wang, R. B.; Gan, M.; Ma, S. G. Illihenin A: An Antiviral Sesquiterpenoid with a Cage-like Tricyclo[6.2.2.01,5]dodecane Skeleton fromIllicium henryi . J. Org. Chem. 2021 , 86, 2017–2022.
[23] Otaka, J.; Hashizume, D.; Masumoto, Y.; Muranaka, A.; Uchiyama, M.; Koshino, H.; Futamura, Y.; Osada, H. Hitoyol A and B, Two Norsesquiterpenoids from the Basidiomycete Coprinopsis cinerea .Org. Lett. 2017 , 19, 4030–4033.
[24] Bu’Lock. J. D.; Darbyshire, J. lagopodin metabolites and artefacts in cultures of coprinus. Phytochem. Lett.1976 , 15, 1433–1433.
[25] Muraguchi, H.; Umezawa, K.; Niikura, M.; Yoshida, M.; Kozaki, T.;Ishii, K.; Sakai, K.; Shimizu, M.; Nakahori, K.; Sakamoto, Y.; Choi, C.; Ngan, C. Y.; Lindquist, E.; Lipzen, A.; Tritt, A.; Haridas, S.; Barry, K.; Grigoriev, I. V.; Pukkila, P. J. Strand-Specific RNA-Seq Analyses of Fruiting Body Development in Coprinopsis cinerea ,PLoS One , 2015 , 10, e0141586.
[26] Lopez-Gallego, F.; Agger, S. A.; Abate-Pella, D.; Distefano, M. D.; Schmidt-Dannert, C. Sesquiterpene synthases Cop4 and Cop6 fromCoprinus cinereus : catalytic promiscuity and cyclization of farnesyl pyrophosphate geometric isomers, Chembiochem.2010 , 11, 1093–1106.
[27] Yang, H. X.; Ai, H. L.; Feng, T.; Wang, W. X.; Wu, B.; Zheng, Y. S.; Sun, H.; He, J.; Li, Z. H.; Liu, J. K. Trichothecrotocins A–C, Antiphytopathogenic Agents from Potato Endophytic FungusTrichothecium crotocinigenum . Org. Lett. 2018 , 20, 8069–8072.
[28] Bunyapaiboonsri, T.; Yoiprommarat, S.; Lapanun, S.; Balram, U.; Chanthaket, R.; Klaysuban, A.; Suetrong, S. Trichothecenes from the fungus Acremonium crotocinigenum BCC 20012. Phytochem. Lett. 2016 , 18, 39–43.
[29] McCormick, S. P.; Stanley, A. M.; Stover, N. A.; Alexander, N. J. Trichothecenes: from simple to complex mycotoxins. Toxins (Basel) . 2011 , 3 , 802–814.
[30] Pipas Saha, U. C.; Reddy, S. Bondalapati and A. K. Saikia, A Novel Synthesis of Oxabicyclo[3.3.1]nonanone via (3,5)-Oxonium-Ene Reaction. Org. Lett. 2010 , 12, 1824–1826.
[31] Ding, J. H.; Feng, T.; Li, Z. H.; Yang, X. Y.; Guo, H.; Yin, X.; Wang, G. Q.; . Liu, J. K. Trefolane A, a Sesquiterpenoid with a New Skeleton from Cultures of the Basidiomycete Tremella foliacea .Org. Lett. 2012 , 14, 4976–4978.
[32] Yang, X. Y.; Feng, T.; Li, Z. H.; Sheng, Y.; Yin, X.; Leng, Y.; Liu, J. K. Conosilane A, an Unprecedented Sesquiterpene from the Cultures of Basidiomycete Conocybe siliginea . Org. Lett.2012 , 14, 5382–5384.
[33] Yuan, H. S.; Dai, Y. C.; Steffen, K. Screening and evaluation of white rot fungi to decolourise synthetic dyes, with particular reference to Antrodiella albocinnamomea . Mycology .2012 , 3, 100–108.
[34] Li, W.; He, J.; Feng, T.; Yang, H. X.; Ai, H. L.; Li, Z. H.; Liu, J. K. Antroalbocin A, an Antibacterial Sesquiterpenoid from Higher Fungus Antrodiella albocinnamomea . Org. Lett.2018 , 20, 8019–8021.
[35] Xie, S.; Wu, Y.; Qiao, Y.; Guo, Y.; Wang, J.; Hu, Z.; Zhang, Q.; Li, X.; Huang, J.; Zhou, Q.; Luo, Z.; Liu, J.; Zhu, H.; Xue, Y.; Zhang, Y. Protoilludane, Illudalane, and Botryane Sesquiterpenoids from the Endophytic Fungus Phomopsis sp. TJ507A. J. Nat. Prod.2018 , 81, 1311–1320.
[36] Liu, H.; Tan, H.; Chen, K.; Chen, Y.; Li, S.; Li, H.; Zhang, W. Cerrenins A–C, cerapicane and isohirsutane sesquiterpenoids from the endophytic fungus Cerrena sp. Fitoterapia . 2018 , 129, 173–178.
[37] Jiao, S.; Su, G.; Zhou, X.; Ge , F.; Liu, C.; Zhang, R.; Peng, B.; Chen, S.; Huang, L.; Tu, P.; Chai, X. Three Pairs of Enantiomeric Sesquiterpenoids from Syringa pinnatifolia . J. Org. Chem.2021 , 86, 7263–7270.
[38] Zhao, H. Y.; Zhou, Q. M.; Zhu, H.; Zhou, F.; Meng, C. W.; Shu, H. Z.; Liu, Z. H.; Peng, C.; Xiong, L. Anisotanols A−D, Four Norsesquiterpenoids with an Unprecedented Sesquiterpenoid Skeleton fromAnisodus tanguticus . Chin. J. Chem. 2021 , 39, 3375–3380.
[39] Guo, Z. K.; Wang, B.; Cai, C. H.; Huang, S. Z.; Yuan, J. Z.; Mei, W. L.; Dai, H. F. Tomenphantadenine, an unprecedented germacranolide-adenine hybrid heterodimer from the medicinal plantElephantopus tomentosus L. Fitoterapia . 2018 , 125, 217–220.
[40] Chen, M.; Cao, J. Q.; Ang, S.; Zeng, T. N.; Li, N. P.; Yang, T. J.; Liu, J. S.; Wu, Y.; Ye, W. C.; Wang, L. Eugenunilones A–H: rearranged sesquiterpenoids from Eugenia uniflora , Org. Chem. Front. 2022. 9 , 667–675.
[41] de Paulo Farias, D.; Neri-Numa, I. A.; de Araujo, F. F.; Pastore, G. M. A critical review of some fruit trees from theMyrtaceae family as promising sources for food applications with functional claims. Food Chem. 2020 , 306, 125630.
[42] Pereira, M. C.; Steffens, R. S.; Jablonski, A.; Hertz, P. F.; Rios Ade, O.; Vizzotto, M.; Flores, S. H. Characterization and antioxidant potential of Brazilian fruits from the Myrtaceaefamily. J. Agric. Food Chem. 2012 , 60, 3061–3067.
[43] Reynertson, K. A.; Yang, H.; Jiang, B.; Basile, M. J.; Kennelly, E. J. Quantitative analysis of antiradical phenolic constituents from fourteen edible Myrtaceae fruits. Food Chem. 2008 , 109, 883–890.
[44] Cai, Y. S.; Wu, Z.; Wang, J. R.; Zheng, X. Q.; Xu, J.; Qiu, G.; Yu, J. Spiroalanfurantones A–D, Four Eudesmanolide-Furan Sesquiterpene Adducts with a Pentacyclic 6/6/5/5/5 Skeleton from Inula helenium . Org. Lett. 2019 , 21, 9478–9482.
[45] Jin, Q.; Lee, J. W.; Jang, H.; Lee, H. L.; Kim, J. G.; Wu, W.; Lee, D.; Kim, E. H.; Kim, Y.; Hong, J. T.; Lee, M. K.; Hwang, B. Y. Dimeric- and trimeric sesquiterpenes from the flower of Inula japonica . Phytochemistry . 2018 , 155, 107–113.
[46] Qin, J. J.; Jin, H. Z.; Huang, Y.; Zhang, S. D.; Shan, L.; Voruganti, S.; Nag, S.; Wang, W.; Zhang, W. D.; Zhang, R.; Selective cytotoxicity, inhibition of cell cycle progression, and induction of apoptosis in human breast cancer cells by sesquiterpenoids fromInula lineariifolia Turcz. Eur. J. Med. Chem.2013 , 68, 473–481.
[47] Qin, J. J.; Wang, L. Y.; Zhu, J. X.; Jin, H. Z.; Fu, J. J.; Liu, X. F.; Li, H. L.; Zhang, W. D. Neojaponicone A, a bioactive sesquiterpene lactone dimer with an unprecedented carbon skeleton fromInula japonica . Chem. Commun. (Camb) , 2011 , 47, 1222–1224.
[48] Qin, J. J.; Huang, Y.; Wang, D.; Cheng, X. R.; Zeng, Q.; Zhang, S. D.; Hu, Z. L.; Jin, H. Z.; Zhang, W. D. Lineariifolianoids A–D, rare unsymmetrical sesquiterpenoid dimers comprised of xanthane and guaiane framework units from Inula lineariifolia . RSC Advances .2012 , 2, 1307–1309.
[49] Zhang, X. F.; Ren, J.;. Cheng, X. R; Jin, H. Z.; Zhang, W. D. One new unusual sesterterpenoid and four new sesquiterpene dimers fromInula britannica . RSC Advances . 2015 , 5, 1979–1982.
[50] Ding, L. F.; Peng, L. Y.; Zhou, H. F.; Song, L. D.; Wu, X. D.; Zhao, Q. S. Artemilavanolides A and B, two sesquiterpenoids with a 6-oxabicyclo[3.2.1]octane scaffold from Artemisia lavandulaefolia . Tetrahedron Lett. 2020, 61 .
[51] Sun, Z.; Zhang, Y.; Peng, X.; Huang, S.; Zhou, H.; Xu, J.; Gu, Q. Diverse Sesquiterpenoids and Polyacetylenes from Atractylodes lancea and Their Anti-Osteoclastogenesis Activity. J. Nat. Prod.2022 , 85, 866–877.
[52] Efferth, T. Willmar Schwabe Award 2006: antiplasmodial and antitumor activity of artemisinin-from bench to bedside. Planta Med. 2007 , 73, 299–309.
[53] Tu, Y. Artemisinin-A Gift from Traditional Chinese Medicine to the World (Nobel Lecture). Angew. Chem. Int. Ed. Engl.2016 , 55, 10210–10226.
[54] Wu, Q. X.; Shi, Y. P.; Jia, Z. J. Eudesmane sesquiterpenoids from the Asteraceae family. Nat. Prod. Rep. 2006 , 23, 699–734.
[55] Wu, Z. J.; Xu, X. K.; Shen, Y. H.; Su, J.; Tian, J. M.; Liang, S.; Li, H. L.; Liu, R. H.; Zhang, W. D. Ainsliadimer A, A New Sesquiterpene Lactone Dimer with an Unusual Carbon Skeleton fromAinsliaea macrocephala . Org. Lett. 2008 . 10, 2397–2400.
[56] Su, L. H.; Geng, C. A.; Li, T. Z.; Ma, Y. B.; Huang, X. Y.; Zhang, X. M.; Chen, J. J. Artatrovirenols A and B: Two Cagelike Sesquiterpenoids from Artemisia atrovirens . J. Org. Chem.2020 , 85, 13466–13471.
[57] Zhao, P.; Li, Z. Y.; Qin, S. Y.; Xin, B. S.; Liu, Y. Y.; Lin, B.; Yao, G. D.; Huang, X. X.; Song, S. J. Three Unusual Sesquiterpenes with Distinctive Ring Skeletons from Daphne penicillata Uncovered by Molecular Networking Strategies. J. Org. Chem. 2021 , 86, 15298–15306.
[58] Liu, Y.; Liu, F.; Qiao, M. M.; Guo, L.; Chen, M. H.; Peng, C.; Xiong, L. Curcumanes A and B, Two Bicyclic Sesquiterpenoids with Significant Vasorelaxant Activity from Curcuma longa . Org. Lett. 2019 , 21, 1197–1201.
[59] Sun, W.; Wang, S.; Zhao, W.; Wu, C.; Guo, S.; Gao, H.; Tao, H.; Lu, J.; Wang, Y.; Chen, X. Chemical constituents and biological research on plants in the genus Curcuma . Crit. Rev. Food Sci. Nutr.2017 , 57, 1451–1523.
[60] Xu, L. L.; Chen, H. L.; Hai, P.; Gao, Y.; Xie, C. D.; Yang, X. L.; Abe, I. (+)- and (-)-Preuisolactone A: A Pair of Caged Norsesquiterpenoidal Enantiomers with a Tricyclo[4.4.01,6.02,8]decane Carbon Skeleton from the Endophytic Fungus Preussia isomera .Org. Lett. 2019 , 21, 1078–1081.
[61] Gonzalez-Menendez, V.; Martin, J.; Siles, J. A.; Gonzalez-Tejero, M. R.; Reyes, F.; Platas, G.; Tormo, J. R.; Genilloud, O. Biodiversity and chemotaxonomy of Preussia isolates from theIberian Peninsula . Mycol. Prog. 2017 , 16, 713–728.
[62] Khan, A. L.; Asaf, S.; Khan, A. R.; Al-Harrasi, A.; Al-Rawahi, A.;. Lee, I. J. First draft genome sequencing of indole acetic acid producing and plant growth promoting fungus Preussia sp. BSL10.J. Biotechnol. 2016 , 225, 44–45.
[63] Zhang, Y. L.; Zhou, X. W.; Wang, X. B.; Wu, L.; Yang, M. H.; Luo, J.; Yin, Y.; Luo, J. G.; Kong, L. Y. Xylopiana A, a Dimeric Guaiane with a Case-Shaped Core from Xylopia vielana : Structural Elucidation and Biomimetic Conversion. Org. Lett. 2017 , 19, 3013–3016.
[64] Fan, Y. Y.; Sun, Y. L.; Zhou, B.; Zhao, J. X.; Sheng, L.; Li, J. Y.; Yue, J. M. Hedyorienoids A and B, Two Sesquiterpenoid Dimers Featuring Different Polycyclic Skeletons from Hedyosmum orientale . Org. Lett. 2018 , 20, 5435–5438.
[65] Su, L. H.; Li, T. Z.; Ma, Y. B.; Geng, C. A.; Huang, X. Y.; Zhang, X.; Gao, Z.; Chen, J. J. Artematrovirenolides A–D and Artematrolides S–Z, Sesquiterpenoid Dimers with Cytotoxicity against Three Hepatoma Cell Lines from Artemisia atrovirens . Chin. J. Chem. 2021 , 40, 104–114.
[66] Wu, Z. L.; Wang, Q.; Wang, J. X.; Dong, H. Y.; Xu, X. K.; Shen, Y. H.; Li, H. L.; Zhang, W. D. Vlasoulamine A, a Neuroprotective [3.2.2]Cyclazine Sesquiterpene Lactone Dimer from the Roots ofVladimiria souliei . Org. Lett. 2018 , 20, 7567–7570.
[67] Zheng, Z. Q.; Wei, W. J.; Zhang, J.; Li, H. Y.; Xu, K.; Xu, J.; Tang, B.; Li, Y.; Gao, K. Heliaquanoids A–E, Five Sesquiterpenoid Dimers from Inula helianthus-aquatica. J. Org. Chem.2019 , 84, 4473–4477.
[68] Li, J.; Chi, J.; Tang, P.; Sun, Y.; Lu, W.; Xu, W.; Wang, Y.; Luo, J.; Kong, L.; Spirolindemers A and B, Lindenane Sesquiterpenoid Oligomers Equipped with Oxaspiro[4.5]decane from Chloranthus henryi . Chin. J. Chem. 2022 , 40, 603–608.
[69] Chi, J.; Xu, W.; Wei, S.; Wang, X.; Li, J.; Gao, H.; Kong, L.; Luo, J. Chlotrichenes A and B, Two Lindenane Sesquiterpene Dimers with Highly Fused Carbon Skeletons from Chloranthus holostegius .Org. Lett. 2019 , 21, 789–792.
[70] Zhou, B.; Liu, Q. F.; Dalal, S.; Cassera, M. B.; Yue, J. M. Fortunoids A–C, Three Sesquiterpenoid Dimers with Different Carbon Skeletons from Chloranthus fortunei . Org. Lett.2017 , 19, 734–737.
[71] Liu, J. W.; Liu, Y.; Yan, Y. M.; Yang, J.; Lu, X. F.; Cheng, Y. X. Commiphoratones A and B, Two Sesquiterpene Dimers from Resina Commiphora , Org. Lett. 2018 , 20, 2220–2223.
[72] Qin, D. P.; Pan, D. B.; Xiao, W.; Li, H. B.; Yang, B.; Yao, X. J.; Dai, Y.; Yu, Y.; Yao, X. S. Dimeric Cadinane Sesquiterpenoid Derivatives from Artemisia annua . Org. Lett.2018 , 20, 453–456.
[73] Zhang, F. L.; Feng, T. Diterpenes Specially Produced by Fungi: Structures, Biological Activities, and Biosynthesis (2010–2020).J. Fungi (Basel) . 2022 , 8, 244.
[74] Zhang, X.; Yin, Y.; Zhou, Y.; Zhu, T.; Wang, M.; Gao, H. Distinctive Cassane Diterpenoids Corroborated Biogenetic Evolutionary Process from Caesalpinia mimosoides with Anti-renal Fibrosis Activity. Chin. J. Chem. 2021 , 40, 617–627.
[75] Wang, Z.; Han, X.; Liu, G.; Zhang, D.; Hou, H.; Xiao, L.; de Voogd, N. J.; Tang, X.; Li, P.; Li, G. Kalihioxepanes A−G: Seven Kalihinene Diterpenoids from Marine Sponge Acanthella cavernosaCollected off the South China Sea. Chin. J. Chem. 2022 , 40, 1785–1792.
[76] Qi, J.; Zhang, Y.; Liu, Q.; Liu, H.; Fan, Y.; Yue, J.; Clerodenoids A–F: C–ring Aromatized and/or Rearranged Abietane Diterpenoids from Clerodendrum chinense var. simplex .Chin. J. Chem. 2021 , 39, 1891–1897.
[77] Hou, X.; Chen, J.; Hou, X.; Gao, P.; Wang, J.; Song, S.; Li, L. Genkwadane F−I, New Daphnane-type Diterpenes from the Flower Buds of Daphne genkwa Sieb.et Zucc. Exhibit Anti-tumor Activities via Inducing Apoptosis. Chin. J. Chem. 2020 , 38, 1600–1606.
[78] Qi, J.; Zhang, Y.; Liu, Q.; Liu, H.; Fan, Y.; Yue, J. Clerodenoids A−F: C-ring Aromatized and/or Rearranged Abietane Diterpenoids from Clerodendrum chinense var. simplex. Chin. J. Chem. 2021 , 39, 1891–1897.
[79] Gonzalez, M. A. Aromatic abietane diterpenoids: their biological activity and synthesis. Nat Prod Rep . 2015 , 32, 684-704.
[80] Lai, J. Z.; Zhang, M. H.; Wu, Y. C.; Zhang, D. Y.; Wu, X. M.; Hua, W. Y. ent-Abietane Lactones from Euphorbia . Mini-Rev. Med. Chem. 2017 , 17, 380–397.
[81] Liu, M.; Wang, W. G.; Sun, H. D.; Pu, J. X. Diterpenoids from Isodon species: an update. Nat. Prod. Rep. 2017 , 34, 1090–1140.
[82] Wang, B.; Jiang, H. Y.; Yang, J.; Li, J.; Yan, B. C.; Chen, X.; Hu, K.; Li, X. R.; Sun, H. D.; Deng, J.; Puno, P. T. Isolation and Bioinspired Total Synthesis of Rugosiformisin A, A Skeleton-Rearranged Abietane-Type Diterpenoid from Isodon rugosiformis . Org. Lett. 2022 , 24, 8104–8108.
[83] Li, L.; Liu, X.; Zhu, D.; Chen, C.; Lin, Y.; Wang, W.; Zhu, L.; Luo, J.; Kong, L. Officinalins A and B, a pair of C23terpenoid epimers with a tetracyclic 6/7/5/5 system from Salvia officinalis . Org. Chem. Front. 2019 , 6,3369–3373.
[84] Xia, F.; Zhang, D.; Wu, C.; Geng, H.; Xu, W.; Zhang, Y.; Yang, X.; Qin, H.; Xu, G. Isolation, structural elucidation, and synthetic study of salviyunnanone A, an abietane derived diterpenoid with a 7/5/6/3 ring system from Salvia yunnanensis . Org. Chem. Front. 2018 , 5, 1262–1266.
[85] Wei, J.; Gao, Y.; Wang, D.; Zhang, X.; Fan, S.; Bao, T.; Gao, X.; Hu, G.; Wang, A.; Jia, J. Discovery of Highly Oxidized Abietane Diterpenoids from the Roots of Euphorbia fischeriana with Anti‐tumor Activities. Chin. J. Chem. 2021 , 39, 2973–2982.
[86] He, J.; Xu, J.; Guo, L.; Xia, C.; Lian, W.; Tian, H.; Zhang, J.; Shi, Y.; Zhang, W. Fischdiabietane A, an Antitumoral Diterpenoid Dimer Featuring an Unprecedented Carbon Skeleton from Euphorbia fischeriana . J. Org. Chem. 2021 , 86, 5894–5900.
[87] Quitt, P.; Mosettig, E.; Cambie, R.; Rutledge, P.; Briggs, L. optical rotary dispersion studies. lviii. The complete absolute configurations of steviol, kaurene and the diterpene alkaloids of the garryfoline and atisine groups, J. Am. Chem. Soc. 1961 , 83, 3720–3722.
[88] Zhao, X.; Cacherat, B.; Hu, Q.; Ma, D. Recent advances in the synthesis of ent –kaurane diterpenoids. Nat. Prod. Rep .2022 , 39, 119–138.
[89] Sun, H.; Huang, S.; Han, Q. Diterpenoids from Isodon species and their biological activities.Nat. Prod. Rep. 2006 , 23, 673–698.
[90] Yang, Q.; Hu, K.; Yan, B.; Liu, M.; Li, X.; Sun, H.; Puno, P. Maoeriocalysins A–D, four novelent–kaurane diterpenoids fromIsodon eriocalyx and their structure determination utilizing quantum chemical calculation in conjunction with quantitative interproton distance analysis. Org. Chem. Front. 2019 , 6, 45–53.
[91] Fan, Y.; Shi, S.; Deng, G.; Liu, H.; Xu, C.; Ding, J.; Wang, G.; Yue, J. Crokonoids A–C, A Highly Rearranged and Dual-Bridged Spiro Diterpenoid and Two Other Diterpenoids from Croton kongensis .Org. Lett. 2020 , 22, 929–933.
[92] Niu, C.; Li, Y.; Liu, Y.; Ma, S.; Liu, F.; Li, L.; Xu, S.; Wang, X.; Wang, R.; Qu, J.; Yu, S. Pierisketolide A and Pierisketones B and C, Three Diterpenes with an Unusual Carbon Skeleton from the Roots of Pieris formosa . Org. Lett. 2017 , 19, 906–909.
[93] Li, Y.; Liu, Y.; Yu, S. Grayanoids from the Ericaceaefamily: structures, biological activities and mechanism of action.Phytochem. Rev. 2013 , 12, 305–325.
[94] Li, C.; Zhang, J.; Zhang, X.; Li, S.; Gao, J. An overview of grayanane diterpenoids and their biological activities from theEricaceae family in the last seven years. Eur. J. Med. Chem. 2019 , 166, 400–416.
[95] Zhou, J.; Zhan, G.; Zhang, H.; Zhang, Q.; Li, Y.; Xue, Y.; Yao, G. Rhodomollanol A, a Highly Oxygenated Diterpenoid with a 5/7/5/5 Tetracyclic Carbon Skeleton from the Leaves of Rhododendron molle . Org. Lett. 2017 , 19, 3935–3938.
[96] Zhou, J.; Zhan, G.; Zhang, H.; Zhang, Q.; Li, Y.; Xue, Y.; Yao, G. Rhodomollanol A, a Highly Oxygenated Diterpenoid with a 5/7/5/5 Tetracyclic Carbon Skeleton from the Leaves of Rhododendron molle . Org. Lett. 2017 , 19, 3935–3938.
[97] Zhou, J.; Liu, J.; Dang, T.; Zhou, H.; Zhang, H.; Yao, G. Mollebenzylanols A and B, Highly Modified and Functionalized Diterpenoids with a 9-Benzyl-8,10-dioxatricyclo[5.2.1.01,5]decane Core from Rhododendron molle . Org. Lett. 2018 , 20, 2063–2066.
[98] Zhou, J.; Zuo, Z.; Liu, J.; Zhang, H.; Zheng, G.; Yao, G. Discovery of highly functionalized 5,6-seco-grayanane diterpenoids as potent competitive PTP1B inhibitors. Org. Chem. Front.2020 , 7, 820–828.
[99] Jin, P.; Yuan, X.; Ma, X.; Zheng, G.; Wang, R.; Sun, N.; Yao, G.; Epoxymicranthols A–N, 5,9‐Epoxygrayanan Diterpenoids as Potent Analgesics from Rhododendron micranthum . Chin. J. Chem.2021 , 39, 1997–2008.
[100] Huang, L.; Zheng, G.; Feng, Y.; Jin, P.; Gao, B.; Zhang, H.; Ma, X.; Zhou, J.; Yao, G. Highly Oxygenated Dimeric Grayanane Diterpenoids as Analgesics: TRPV1 and TRPA1 Dual Antagonists fromRhododendron molle . Chin. J. Chem. 2022 , 40, 2285–2295.
[101] Li, Y.; Zhu, Y.; Zhang, Z.; Li, L.; Liu, Y.; Qu, J.; Ma, S.; Yu, S.; Antinociceptive grayanane-derived diterpenoids from flowers ofRhododendron molle . Acta Pharm. Sin. B . 2020 , 10, 1073–1082.
[102] Schmidt, R. The biosynthesis of tigliane and related diterpenoids; an intriguing problem. Bot. J. Linn. Soc.1987 , 94, 221–230.
[103] Zhang, W.; Zhao, J.; Sheng, L.; Fan, Y.; Li, J.; Gao, K.; Yue, J. Mangelonoids A and B, Two Pairs of Macrocyclic Diterpenoid Enantiomers from Croton mangelong . Org. Lett.2018 , 20, 4040–4043.
[104] Yang, M.; Li, X.; Wang, J.; Lei, X.; Tang, W.; Li, X.; Sun, H.; Guo, Y. Sarcomililate A, an Unusual Diterpenoid with Tricyclo[11.3.0.02,16]hexadecane Carbon Skeleton, and Its Potential Biogenetic Precursors from the Hainan Soft CoralSarcophyton mililatensis . J. Org. Chem . 2019 , 84, 2568–2576.
[105] Chen, F. L.; Liu, D. L.; Fu, J.; Yang, J.; Bai, L. P.; Zhang, W.; Jiang, Z. H.; Zhu, G. Y. (±)-Atrachinenins A–C, Three Pairs of Caged C27 Meroterpenoids from the Rhizomes of Atractylodeschinensis. Chin. J. Chem. 2021 , 40, 460–466.
[106] Wang, C.; Jin, T.; Liu, X.; Zhang, J.; Shi, X.; Wang, M.; Huang, R.; Zhang, Y.; Liu, K.; Li, G. Sinudenoids A–E, C(19)–Norcembranoid Diterpenes with Unusual Scaffolds from the Soft Coral Sinularia densa. Org. Lett. 2022 , 24, 9007–9011.
[107] Zeng, Z.; Li, W.; Nay, B.; Hu, P.; Zhang, H.; Wang, H.; Li, X.; Guo, Y. Sinunanolobatone A, an Anti-inflammatory Diterpenoid with Bicyclo[13.1.0]pentadecane Carbon Scaffold, and Related Casbanes from the Sanya Soft Coral Sinularia nanolobata . Org. Lett.2021 , 23, 7575–7579.
[108] Wu, M.; Liu, J.; Wang, J.; Zhang, J.; Wang, H.; Jiang, C.; Guo, Y. Sinucrassins A–K, Casbane‐type Diterpenoids from the South China Sea Soft Coral Sinularia crassa . Chin. J. Chem.2021 , 39, 2367–2376.
[109] Liu, J.; Wu, M.; Li, H.; Wang, H.; Tang, W.; Gu, Y.; Li, X.; Guo, Y. Unusual polyoxygenated casbane diterpenoids from the South China Sea soft coral Sinularia erecta . Bioorg. Chem.2021 , 114, 105028.
[110] Liu, J.; Li, H.; Wu, M. J.; Tang, W.; Wang, J. R.; Gu, Y. C.; Wang, H.; Li, X. W.; Guo, Y. W. Sinueretone A, a Diterpenoid with Unprecedented Tricyclo[12.1.0.05,9]pentadecane Carbon Scaffold from the South China Sea Soft Coral Sinularia erecta.J. Org. Chem. 2021 , 86, 10975–10981.
[111] Maslovskaya, L.; Savchenko, A.; Krenske, E.; Chow, S.; Gordon, V.; Reddell, P.; Pierce, C.; Parsons, P.; Boyle, G.; Williams, C. EBC–342: A Novel Tetrahydrofuran Moiety Containing Casbane from theAustralian Rainforest . Eur. J. Org. Chem. 2020 , 2020, 1042–1045.
[112] Maslovskaya, L.; Savchenko, A.; Pierce, C.; Boyle, G.; Gordon, V.; Reddell, P.; Parsons, P.; Williams, C. New Casbanes and the Firsttrans -Cyclopropane seco -Casbane from the Australian Rainforest Plant Croton insularis . Chemistry.2019 , 25, 1525–1534.
[113] Ye, K.; Ai, H. Pimarane Diterpenes from Fungi.Pharmaceuticals . 2022 , 15, 1291.
[114] Reveglia, P.; Cimmino, A.; Masi, M.; Nocera, P.; Berova, N.; Ellestad, G.; Evidente, A. Pimarane diterpenes: Natural source, stereochemical configuration, and biological activity. Chirality .2018 , 30, 1115–1134.
[115] Zhou, J.; Wu, Z.; Guo, B.; Sun, M.; Onakpa, M.; Yao, G.; Zhao, M.; Che, C. Modified diterpenoids from the tuber of Icacina oliviformis as protein tyrosine phosphatase 1B inhibitors. Org. Chem. Front. 2020 , 7, 355–367.
[116] Pu, D.; Du, B.; Chen, W.; Gao, J.; Hu, K.; Shi, N.; Li, Y.; Zhang, X.; Zhang, R.; Li, X.; Zhang, H.; Wang, F.; Xiao, W. Premnafulvol A: A Diterpenoid with a 6/5/7/3–Fused Tetracyclic Core and Its Biosynthetically Related Analogues from Premna fulva . Org. Lett. 2018 , 20, 6314–6317.
[117] Gao, X.; Zheng, Y.; Zhang, X.; Hu, G.; Jia, J.; Wang, A. ent‐Pimaran Diterpenoid Dimers from Sigesbeckia glabrescens with Potent Anti‐inflammatory Activities. Chin. J. Chem.2021 , 39, 3315–3321.
[118] Hu, Z.; Sun, W.; Li, F.; Guan, J.; Lu, Y.; Liu, J.; Tang, Y.; Du, G.; Xue, Y.; Luo, Z.; Wang, J.; Zhu, H.; Zhang, Y. Fusicoccane-Derived Diterpenoids from Alternaria brassicicola : Investigation of the Structure-Stability Relationship and Discovery of an IKKbeta Inhibitor. Org. Lett. 2018, 20, 5198–5202.
[119] Li, F.; Sun, W.; Guan, J.; Lu, Y.; Zhang, S.; Lin, S.; Liu, J.; Gao, W.; Wang, J.; Hu, Z.; Zhang, Y. Alterbrassicicene A, a Highly Transformed Fusicoccane-Derived Diterpenoid with Potent PPAR-γ Agonistic Activity from Alternaria brassicicola .Org. Lett. 2018 , 20, 7982–7986.
[120] Li, F.; Lin, S.; Zhang, S.; Hao, X.; Li, X.; Yang, B.; Liu, J.; Wang, J.; Hu, Z.; Zhang, Y. Alterbrassinoids A–D: Fusicoccane-Derived Diterpenoid Dimers Featuring Different Carbon Skeletons from Alternaria brassicicola . Org. Lett.2019 , 21, 8353–8357.
[121] Zhou, P.;. Zhang, X; Dai, C.; Yan, S.; Wei, M.; Feng, W.; Li, Q.; Liu, J.; Zhu, H.; Hu, Z.; Chen, C.; Zhang, Y. Talaromynoids A–E: Five New Fusicoccane Diterpenoids from the Endop hytic FungusTalaromyces sp. DC-26. J. Org. Chem. 2022 , 87, 7333–7341.
[122] Fattahian, M.; Ghanadian, M.; Ali, Z.; Khan, I. Jatrophane and rearranged jatrophane–type diterpenes: biogenesis, structure, isolation, biological activity and SARs (1984–2019). Phytochem Rev. 2020 , 19, 265–336.
[123] Xiang, Z.; Tong, Q.; Su, J.; Hu, Z.; Zhao, N.; Xia, R.; Wu, J.; Chen, C.; Chen, J.; Wan, L. Diterpenoids with Rearranged 9(10→11)-abeo -10,12-Cyclojatrophane Skeleton and the First (15S)-Jatrophane from Euphorbia helioscopia : Structural Elucidation, Biomimetic Conversion, and Their Immunosuppressive Effects.Org. Lett. 2022 , 24, 697–701.
[124] Li, W.; Tang, Y.; Chen, S.; Tang, G.; Gan, L.; Li, C.; Rao, Y.; Huang, Z. ; Yin, S. Euphorhelipanes A and B, Triglyceride-LoweringEuphorbia Diterpenoids with a Bicyclo[4.3.0]nonane Core fromEuphorbia helioscopia . J. Nat. Prod. 2019 , 82, 412–416.
[125] Li, W.; Tang, Y.; Sang, J.; Fan, R.; Tang, G.; Yin, S. Jatrofolianes A and B: Two Highly Modified Lathyrane Diterpenoids fromJatropha gossypiifolia . Org. Lett. 2020 , 22, 106–109.
[126] Wu, S.; Fan, R.; Yuan, F.; Li, W.; Huang, D.; Li, S.; Tang, G.; Huang, Z.; Yin, S. Euphylonoids A and B, Two Highly Modified Jatrophane Diterpenoids with Potent Lipid-Lowering Activity fromEuphorbia hylonoma . Org. Lett. 2022 , 24, 8854–8858
[127] Máximoa, P.; Lourenço, A. Marine Sesterterpenes: An Overview,Curr. Org. Chem. 2018 , 22, 2381–2393.
[128] Guo, K.; Liu, Y.; Li, S. The untapped potential of plant sesterterpenoids: chemistry, biological activities and biosynthesis.Nat. Prod. Rep. 2021 , 38, 2293–2314.
[129] Guo, K.; Luo, S.; Guo, D.; Li, D.; Hua, J.; Liu, Y.; Liu, Y.; Li, S. A monocarbocyclic sesterterpenoid biosynthetic precursor of leucosceptroids from Leucosceptrum canum and its metabolic isomerization by a specialist insect. Org. Chem. Front.2022 , 9, 2209–2214.
[130] Jiao, W.; Hong, L.; Sun, J.; Piao, S.; Chen, G.; Deng, H.; Wang, S.; Yang, F.; Lin, H. (±)-Hippolide J, a Pair of Unusual Antifungal Enantiomeric Sesterterpenoids from the Marine Sponge Hippospongia lachne .Eur. J. Org. Chem. 2017 , 2017, 3421–3426.
[131] Chen, Z.; Chen, X.; Tang, Y.; Zhou, Y.; Deng, H.; He, J.; Liu, Y.; Zhao, Z.; Cui, H. Linderasesterterpenoids A and B: Two 7-Cyclohexyldecahydroazulene Carbon Skeleton Sesterterpenoids Isolated from the Root of Lindera glauca . Org. Lett. 2022 , 24, 3717–3720.
[132] Guo, K.; Liu, X.; Zhou, T.; Liu, Y.; Liu, Y.; Shi, Q.; Li, X.; Li, S. Gentianelloids A and B: Immunosuppressive 10,11-seco -Gentianellane Sesterterpenoids from the Traditional Uighur Medicine Gentianella turkestanorum . J. Org. Chem.2020 , 85, 5511–5515.
[133] Teng, L.; Mu, R.; Liu, Y.; Xiao, C.; Li, D.; Gao, J.; Guo, K.; Li, X.; Liu, Y.; Zeng, F.; Li, S. Immunosuppressive and Adipogenesis Inhibitory Sesterterpenoids with a Macrocyclic Ether System fromEurysolen gracilis , Org. Lett. 2021 , 23, 2232–2237.
[134] Wang, J.; Yu, J.; Shu, Y.; Shi, Y.; Luo, P.; Cai, L.; Ding, Z. Peniroquesines A-C: Sesterterpenoids Possessing a 5-6-5-6-5-Fused Pentacyclic Ring System from Penicillium roqueforti YJ-14.Org. Lett. 2018 , 20, 5853–5856.
[135] Li, Q.; Chen, C.; Wei, M.; Dai, C.; Cheng, L.; Tao, J.; Li, X.; Wang, J.; Sun, W.; Zhu, H.; Zhang, Y. Niduterpenoids A and B: Two Sesterterpenoids with a Highly Congested Hexacyclic 5/5/5/5/3/5 Ring System from the Fungus Aspergillus nidulans . Org. Lett.2019 , 21, 2290–2293.
[136] Hill, R. A.; Connolly, J. D. Triterpenoids. Nat. Prod. Rep. 2017 , 34, 90–122.
[137] Hill, R. A.; Connolly, J. D. Triterpenoids. Nat. Prod. Rep. 2018 , 35, 1294–1329.
[138] Hill, R. A.; Connolly, J. D. Triterpenoids. Nat. Prod. Rep. 2020 , 37, 962–998.
[139] Jiang, W.; Fei, Y.; Du, X.; Mu, Z.; Li, B.; Zhang, S.; Zhong, G. Saxifraganoids A and B, two novel cucurbitane triterpenoid glycosides from Saxifraga umbellulata var. pectinata. Tetrahedron Lett. 2017 , 58, 3541–3544.
[140] Zhang, Y.; Zhao, L.; Huang, S. W.; Wang, W.; Song, S. J. Triterpene saponins with neuroprotective effects from the leaves ofDiospyros kaki Thunb . Fitoterapia . 2018 , 129, 138–144.
[141] Chen, X. Q.; Chen, L. X.; Zhao, J.; Tang, Y. P.; Li, S. P. Nortriterpenoids from the Fruiting Bodies of the Mushroom Ganoderma resinaceum. Molecules . 2017 , 22, 1073.
[142] Zhao, K.; Sun, S.; Wang, H.; Wang, L.; Qin, G.; Fan, J.; Guo, M.; Wang, W. alpha-Glucosidase inhibitory triterpenoids fromEuonymus fortunei . Bioorg. Chem. 2021 , 111, 104980.
[143] Luo, S. Y.; Pu, R.; Tang, Y. Q.; Fan, R. Z.; Yin, S.; Tang, G. H. Euphane- and 19(10→9)abeo-euphane-type triterpenoids from Jatropha gossypiifolia. Fitoterapia . 2020 , 143, 104582.
[144] Song, M.; Chan, G.; Lin, L.; Li, D.; Zhang, K.; Zhang, X.; Ye, W.; Li, N.; Zhang, Q. Triterpenoids from the fruits of Melia azedarach L. and their cytotoxic activities. Phytochemistry .2022 , 201, 113280.
[145] Novakovic, M.; Nikodinovic-Runic, J.; Veselinovic, J.; Ilic-Tomic, T.; Vidakovic, V.; Tesevic, V.; Milosavljevic, S. Bioactive Pentacyclic Triterpene Ester Derivatives from Alnus viridis ssp.viridis Bark. J. Nat. Prod. 2017 , 80, 1255–1263.
[146] Li, Z.; Qi, F.; Zhi, D.; Hu, Q.; Liu, Y.; Zhang, Z.; Fei, D. A novel spirocyclic triterpenoid and a new taraxerane triterpenoid from Teucrium viscidum .Org. Chem. Front. 2017 , 4, 42–46.
[147] Han, Q.; Qian, Y.; Wang, X.; Zhang, Q.; Cui, J.; Tu, P.; Liang, H. Cytotoxic oleanane triterpenoid saponins from Albizia julibrissin . Fitoterapia . 2017 , 121, 183–193.
[148] Sakai, Y.; Shinozaki, J.; Takano, A.; Masuda, K.; Nakane, T. Three novel 14-epiarborane triterpenoids from Imperata cylindrica Beauv. var. major. Phytochem. Lett. 2018 , 26, 74–77.
[149] Ur Rehman, N.; Khan, A.; Al-Harrasi, A.; Hussain, H.; Wadood, A.; Riaz, M. ; Al-Abri, Z. New alpha-Glucosidase inhibitors from the resins of Boswellia species with structure-glucosidase activity and molecular docking studies. Bioorg. Chem. 2018 , 79, 27–33.
[150] Dinku, W.; Isaksson, J.; Rylandsholm, F.; Bouř, P.; Brichtová, E.; Choi, S.; Lee, S.; Jung, Y.; No, Z.; Svendsen, J.; Aasen, A.; Dekebo, A. Anti–proliferative activity of a novel tricyclic triterpenoid acid from Commiphora africana resin against four human cancer cell lines. Appl. Biol. Chem. 2020 , 63, 16.
[151] Ni, G.; Li, J.; Yu, D. Belamchinenin A, an unprecedented tricyclic–fused triterpenoid with cytotoxicity from Belamcanda chinensis . Org. Biomol. Chem. 2018 , 16, 3754–3759.
[152] Liu, X.; Li, C.; Chen, F.; Ma, J.; Wang, S.; Yuan, Y.; Li, L.; Zhang, D. Nototronesides A−C, Three Triterpene Saponins with a 6/6/9 Fused Tricyclic Tetranordammarane Carbon Skeleton from the Leaves ofPanax notoginseng . Org. Lett. 2018 , 20, 4549–4553.
[153] Sidjui, L.; Eyong, K.; Hull, K.; Folefoc, G.; Leddet, V.; Herbette, G.; Ollivier, E.; Taube, J.; Klausmeyer, K.; Romo, D. Bioactive Seco-Lanostane-Type Triterpenoids from the Roots ofLeplaea mayombensis . J. Nat. Prod. 2017 , 80, 2644–2651.
[154] Meng, L.; Wang, Q.; Tang, T.; Xiao, S.; Zhang, L.; Zhou, D.; Yu, F. Design, Synthesis and Biological Evaluation of Pentacyclic Triterpene Dimers as HCV Entry Inhibitors. Chin. J. Chem.2017 , 35, 1322–1328.
[155] Peng, X.; Huang, Y.; Lu, S.; Yang, J.; Qiu, M. Ganolearic Acid A, a Hexanorlanostane Triterpenoid with a 3/5/6/5-Fused Tetracyclic Skeleton from Ganoderma cochlear . J. Org. Chem.2018 , 83, 13178–13183.
[156] Wang, C.; Huo, X.; Luan, Z.; Cao, F.; Tian, X.; Zhao, X.; Sun, C.; Feng, L.; Ning, J.; Zhang, B.; Ma, X. Alismanin A, a Triterpenoid with a C34 Skeleton from Alisma orientale as a Natural Agonist of Human Pregnane X Receptor. Org. Lett.2017 , 19, 5645–5648.
[157] Hua, J.; Liu, Y. C.; Luo, S. H.; Liu, Y.; Xiao, C. J.; Li, X. N.; Li, S. H. Immunostimulatory 6/6/6/6 Tetracyclic Triterpenoid Saponins with the Methyl-30 Incorporated Cyclization from the Root ofColquhounia elegans . Org. Lett. 2021 , 23, 7462–7466.
[158] Su, H.; Liang, H.; Hu, G.; Zhou, L.; Peng, X.; Bi, H.; Qiu, M. Applanoids A−E as the First Examples of C‐15/C‐20 Michael Adducts in Ganoderma Triterpenoids and Their PXR Agonistic Activity. Chin. J. Chem. 2022 , 40, 2633–2641.
[159] Tang, Y.; Zhao, Z. Z.; Hu, K.; Feng, T.; Li, Z. H.; Chen, H. P.; Liu, J. K. Irpexolidal Represents a Class of Triterpenoid from the Fruiting Bodies of the Medicinal Fungus Irpex lacteus . J. Org. Chem. 2019 , 84, 1845–1852.
[160] Song, Y.; Miao, J.; Qin, F.; Yan, Y.; Yang, J.; Qin, D.; Hou, F.; Zhou, L.; Cheng, Y. Belamchinanes A−D from Belamcanda chinensis : Triterpenoids with an Unprecedented Carbon Skeleton and Their Activity against Age-Related Renal Fibrosis. Org. Lett.2018 , 20, 5506–5509.
[161] Hu, B. Y.; Zhao, Y. L.; Xiong, D. S.; He, Y. J.; Zhou, Z. S.; Zhu, P. F.; Wang, Z. J.; Wang, Y. L.; Zhao, L. X.; Luo, X. D. Potent Antihyperuricemic Triterpenoids Based on Two Unprecedented Scaffolds from the Leaves of Alstonia scholaris . Org. Lett.2021 , 23, 4158–4162.
[162] Song, J.; Zhou, M.; Zhou, J.; Liang, J. J.; Peng, X. G.; Liu, J.; Ruan, H. L. Schincalactones A and B, Two 5/5/6/11/3 Fused Schinortriterpenoids with a 13-Membered Carbon Ring System fromSchisandra incarnata . Org. Lett. 2018 , 20, 2499–2502.
[163] Shi, Y. M.; Hu, K.; Pescitelli, G.; Liu, M.; Li, X. N.; Du, X.; Xiao, W. L.; Sun, H. D.; Puno, P. T. Schinortriterpenoids with Identical Configuration but Distinct ECD Spectra Generated by Nondegenerate Exciton Coupling. Org. Lett. 2018 , 20, 1500–1504.
[164] Huang, S.; Li, R.; Liu, J.; Lu, Y.; Chang, Y.; Lei, C.; Xiao, W.; Yang, L.; Zheng, Q.; Sun, H. Isolation and Characterization of Biogenetically Related Highly Oxygenated Nortriterpenoids fromSchisandra chinensis . Org. Lett. 2007 , 9, 2079–2082.
[165] Gao, X.; Wang, X.; Zhou, J.; Zhang, Y.; Liu, H.; Zhou, B.; Yue, J. Rearranged Dichapetalin‐Type Triterpenoids with Cytotoxic Activity from Dichapetalum gelonioides . Chin. J. Chem.2022 , 40, 2531–2538.
[166] Fan, Y.; Gan, L.; Liu, H.; Li, H.; Xu, C.; Zuo, J.; Ding, J.; Yue, J. Phainanolide A, Highly Modified and Oxygenated Triterpenoid fromPhyllanthus hainanensis . Org. Lett. 2017 , 19, 4580–4583.
[167] Grigalunas, M.; Brakmann, S.; Waldmann, H. Chemical Evolution of Natural Product Structure. J. Am. Chem. Soc. 2022 , 144, 3314–3329.
[168] Hu, Z.; Ye, Y.; Zhang, Y. Large-scale culture as a complementary and practical method for discovering natural products with novel skeletons. Nat. Prod. Rep . 2021 , 38, 1775–1793.