Echinulin, a Novel Cyclic Dipeptide Carrying a Triprenylated Indole Moiety from an Anacardiaceae, a Cucurbitaceae and Two Orchidaceae Plants: Detailed High Resolution 2D‐NMR and Mass Spectral Studies.

Metabolites from the marine fungus Eurotium repens

“…Another proton with HMBC correlations with C-2 (δ C 141.4), C-3 (δ C 104.1), C-8 (δ C 128.9), and C-9 (δ C 132.2) was located on a N atom in an indole ring. These data and the presence of a α,α-dimethylallyl group (δ H 1.51, 6H, δ C 27.8, 27.9; δ H 5.15, 2H, m, δ C 112.3; δ H 6.10, 1H, dd, δ C 145.7) and two isopentenyl substituents indicated that 4 belonged to the echinulin series of metabolites, which are characteristic of certain higher plants and fungi [14][15][16][17][18]. The mass spectrum, NMR spectra, and specific rotation were in excellent agreement with those of echinulin isolated from higher plants [14].…”

Dioxopiperazine Alkaloids Produced by the Marine Mangrove Derived Endophytic Fungus Eurotium rubrum

“…in the 13 C-NMR spectrum of 3 were replaced by the olefinic CH group and quaternary C-atom at d(C) 114.9 (C(8)) and 128.1 (C(9)), respectively, in the (Table). Detailed examination of the NMR spectral data and comparison with those reported for echinulin (4, Table) [9] showed that the structures of these two compounds are very similar. However, in the 1 H-NMR spectrum, the aliphatic CH 2 Hatom signals at d(H) 3.19 (dd, H a ÀC (8)) and 3.66 (dd, H b ÀC (8)) and the aliphatic CH group at d(H) 4.40 (br.…”

“…In addition, eight known dioxopiperazine derivatives, including variecolorin L (3) [8], echinulin (4) [9], isoechinulin A (5) [10], dihydroxyisoechinulin A (6) [4], preechinulin (7) [11], neoechinulin A (8) [12], neoechinulin E (9) [12], and cryptoechinuline D (10) [13], were also isolated and identified. It deserves to be mentioned that just at the time when we started to prepare this manuscript, compound 3 was reported as a new metabolite of Aspergillus variecolor B-17, a halotolerant fungal strain isolated from a sediment collection of a salt field in inner Mongolia, China [8].…”

Rhus parviflora and its biflavonoid constituent, rhusflavone, induce sleep through the positive allosteric modulation of GABAA-benzodiazepine receptors

“…The fruits of R. parviflora contain echinulin, trimethyl citrate and citric acid 2-methyl ester (Talapatra et al, 1993(Talapatra et al, , 2001. Recent investigation of Shrestha (2011) determined presence of a flavanone naringenin as major component together with flavonoids, biflavonoids, flavonoid glucosides, triterpenoid, sterols, lipids, lignan, lignan glycosides, sterols, phenolic acid and phenolic acid glycosides from RPME.…”