Echingridimer A, an Oxaspiro Dimeric Sesquiterpenoid with a 6/6/5/6/6 Fused Ring System from Echinops grijsii and Aphicidal Activity Evaluation

Abstract

A new dimeric eudesmane sesquiterpenoid with an unreported 6/6/5/6/6 fused carbon skeleton, echingridimer A (1), and five monomers (2–6), including two new compounds (2 and 3), were isolated from the roots of Echinops grijsii. Their structures and absolute configurations were elucidated by comprehensive spectroscopic analyses and confirmed by X-ray crystallography or electronic circular dichroism spectra. Compound 1 represents the first example of a 3,15′-linked Michael-type adduct of two eudesmanes, which feature a unique 1-oxaspiro[4.5]­decan moiety. The plausible biogenetic pathway for 1–6 was briefly discussed. The oxaspiro dimer (1) not only showed stronger aphicidal activity than closely related monomeric compounds (2–6) and the commercial aphicide pymetrozine but also exhibited remarkable insecticide activity against a broad range of aphids, thus could be used as a potential biobased insecticide to suppress aphids.

A Review of the Phytochemistry and Biological Activities of Echinopsis Radix

“…niveum, P. infestans, C. gloeosporioides, and A. alternate). Among them, compared with the commercial fungicide carbendazim, compounds 9, 10, 31-33, 35, and 36 exhibited equal or better antifungal activity against six plant pathogenic fungi [23]. Importantly, the antifungal activities of dimeric dithiophene 47-49 were first reported by Wu Haibo et al The results showed that they had good antifungal activity against five plant pathogenic fungi.…”

“…Specially, compounds 32 and 35 were the most potent thiophenes against M. incognita with LC 50 values 2.57 and 0.91 µg/mL in light, 1.80 and 0.86 µg/mL in dark, respectively [11]. Subsequently, Liu Tingting et al also reported that the new framework of sesquiterpene dimers 66 exhibited stronger insecticidal activity than sesquiterpene compounds 68-72, and even stronger insecticidal activity against aphids than the commercially available aphid fungicide pyrimethadone [23]. Additionally, Wu Haibo et al demonstrated for the first time that compounds 47-49 of dithiophene dimer had better nematicidal activity against Meloidogyne incognita than commercial nematicides ethoxyphosphorus, and had no phototoxicity [20].…”

“…And compound 65 is an unprecedented new carbon skeleton dimer sesquiterpene formed by the cyclization of two eudesmane-type sesquiterpenes. Compounds 66 and 68-72 were isolated from the ethyl acetate extraction portion of the root of E. grijsii [23]. And compound 66 represented a totally new carbon skeleton of the disesquiterpenoid, featuring a unique 6/6/5/6/6 ring system with an oxaspiro unit.…”