Aquilanols A and B, Macrocyclic Humulene-Type Sesquiterpenoids from the Agarwood of Aquilaria malaccensis

Abstract

Four new and five known sesquiterpenoids were isolated from the agarwood of Aquilaria malaccensis. Aquilanols A and B (1 and 2) have an unprecedented macrocyclic humulene structure with a bicyclic 7/10 ring system. Compound 2 was obtained as a scalemic mixture that was resolved by HPLC analysis using a chiral column. Their structures were deduced based on spectroscopic data analysis, and the absolute configurations were unambiguously determined by X-ray crystallographic data and ECD spectroscopic analysis. A putative biosynthetic pathway of these sesquiterpenoids is proposed.

UPLC-MS-guided isolation of single ether linkage dimeric 2-(2-phenylethyl)chromones from Aquilaria sinensis

“…In conclusion, eleven novel uncommon single ether linkage dimeric compounds (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11) were isolated from the articial hole-induced agarwood originating from Aquilaria sinensis. Herein, we reported the NMR and MS data of these compounds, as well as the absolute congurations of 1-9 using ECD spectra.…”

“…Agarwood, widely used in perfumes, incenses, and traditional medicine, is an aromatic dark resin produced by the heartwood of the Aquilaria and Gyrinops species of the Thymelaeaceae family when suffering from a natural or articial injury. [1][2][3] Aquilaria sinensis (Lour. ), which is distributed in southern China, is a peculiar plant resource of Chinese agarwood.…”

Reassignments and Corroborations of Oxo‐Bridged Natural Products Directed by OSE and DU8+ NMR Computation

“…Having explored the effect of oxygen substitution on OSEs,t welve oxo-bridged natural products that have been proposed in the literature were evaluated (i.e., 19-29, Figure 3). [20][21][22][23][24][25][26][27][28][29][30] Thec alculated OSEs were observed to range from À13.9 to 32.1 kcal mol À1 .O nly hugonianene A( 29)h ad an OSE value greater than 30 kcal mol À1 ,that is,diagnostic for unstable.F or the remaining NPs,t he OSE analysis raised no red flags for suspect structural assignments.T his was not Figure 2. Calculated OSEs (OPLS_2005, kcal mol À1 )ofparent oxobridged alkenes corresponding to known isolable skeletons.…”

Reassignments and Corroborations of Oxo‐Bridged Natural Products Directed by OSE and DU8+ NMR Computation

“…Having explored the effect of oxygen substitution on OSEs, twelve oxo‐bridged natural products that have been proposed in the literature were evaluated (i.e., 19 – 29 , Figure ) . The calculated OSEs were observed to range from −13.9 to 32.1 kcal mol −1 .…”