Guaiane-type sesquiterpenoids with various ring skeletons from Daphne bholua uncovered by molecular networking and structural revisions of previously reported analogues

Rapid screening of unprecedented sesquiterpenes with distinctive ring skeletons from Daphne aurantiaca employing an integrated strategy

“…In the 1 H and 13 C NMR spectra, two ester carbonyl groups, one double bond, and two methyl groups were observed. 1 H-1 H COSY correlations of H 2 -2/H 2 -3/H-4/H-5/H 2 -6/H 3 -15, along with HMBC correlations from H 2 -2 to C-10, from H-4 to C-1, from H-5 to C-7, from H 3 -14 to C-1, C-9 and C-10, and from OCH 3 -7 to C-7, supported that 4, featuring an unprecedented skeleton, originated from a guaiane-type sesquiterpenoid by degradation of an isopropyl fragment (C-11/12/13) and cleavage of the carbon-carbon bond (C-7/8) (Fig. S3 †).…”

“…As the major bioactive components of the genus Daphne, these compounds usually exhibit diverse biological properties, especially cholinesterase (ChE) inhibitory, neuroprotective, and anti-neuroinflammatory activities. [1][2][3] Rearrangement, oxidative cleavage, and aldol condensation occurring spontaneously at multiple sites of the structure typically, operated by the energy derived from the enzymatic catalysis of spontaneous reactions, immensely increase the structural diversity of natural guaiane-type sesquiterpenoids. [4][5][6][7][8] The unusual rearranged and highly oxygenated structural features make us take a fresh look at efficient strategies for precision mining of novel skeletal structures with promising pharmacological activities.…”

“…1 H-1 H COSY spectrum showed correlations of H 2 -2/H 2 -3/H-4/H-5/H 2 -6/H 3 -15, allowing us to elucidate the existence of moiety A, shown in Fig.5a. The highly oxidized moieties B and C were deduced by HMBC correlations from H 3 -13 to C-7/C-11/C-12 and from H 3 -14 to C-1/C-9/C-10.…”

Molecular Networking-Guided Isolation of a Phenolic Constituent from Prunus mume Seed and Its Antioxidant and Anti-Inflammatory Activities

“…Subsequently, a NAP experiment was conducted to predict candidate structures for ID 77030 ( Figure 5 C). NAP analysis was performed with the in silico fragmentation tool MetFrag, which calculates a score that indicates how well the candidate could match a given MS/MS spectrum [ 37 ]. Top ranked candidate structures were predicted and the results revealed that ID 7030 could be ferulic acid or isoferulic acid, by MetFrag score 1 ( Figure 5 D).…”

Stereochemical investigations of bioactive dihydrobenzofuran-type lignanamides from Solanum lyratum: chiral resolution, in vitro and in silico profiling

“…The AChE inhibitory activities of all isolates ( 1a/1b–7 ) were obtained via an Ellman assay as previously described. 34–36…”