Linderalides A–D, Disesquiterpenoid–Geranylbenzofuranone Conjugates from Lindera aggregata

Abstract

Four disesquiterpenoid−geranylbenzofuranone conjugates, linderalides A−D (1−4), were isolated from Lindera aggregata. Compounds 1−3 represent the first examples of disesquiterpenoid−geranylbenzofuranone hybrids directly linked by two C−C bonds. Linderalide D ( 4) bears an unprecedented carbon skeleton featuring an unusual linearly 6/ 6/5/6/6 pentacyclic ring system fused by a sesquiterpenoid unit and a geranylbenzofuranone moiety. Their structures and absolute configurations were elucidated by extensive spectroscopic data and electronic circular dichroism analysis. Their biosynthetic pathways were also proposed.

Chaetomadrasins A and B, Two New Cytotoxic Cytochalasans from Desert Soil-Derived Fungus Chaetomium madrasense 375

“…The conformers of 1 and 2 were calculated via ECD using the Time-dependent Density functional theory (TD-DFT) method at the B3LYP/6-31+G (d,p) level in MeOH, and the rotational strengths of 30 excited states were calculated. ECD spectra were generated using the SpecDis 1.6 (University of Würzburg, Würzburg, Germany) and GraphPad Prism 5 (University of California San Diego, USA) software by applying Gaussian band shapes with sigma = 0.3 eV from dipole-length rotational strengths [28].…”

Linderaggrenolides A–N, Oxygen-Conjugated Sesquiterpenoid Dimers from the Roots of Lindera aggregata

“…The dried roots of L. aggregata were ground to powder and extracted with 80% EtOH (4 × 12 L) under reflux. , The extract was then concentrated in vacuo at 50 °C. The extract was successively partitioned with petroleum ether (60–90 °C), EtOAc, and n -butanol.…”

“…Phytochemical investigations into this species have revealed the presence of miscellaneous types of natural products such as sesquiterpenoids, , alkaloids, flavonoids, lignans, condensed tannins, and cyclopentenediones . Our previous phytochemical studies on this plant lead to the isolation of two methine- or methylene-bridged sesquiterpenoid trimers possessing a unique C 46 skeleton, four carbon-bridged disesquiterpenoids with a C 33 or C 31 skeleton, and four disesquiterpenoid–geranylbenzofuranone conjugates. , The preliminary results showed that the ethanol extract from the roots of L. aggregata exhibited the transforming growth factor (TGF)-β inhibitory activity.…”

“…9 Our previous phytochemical studies on this plant lead to the isolation of two methine-or methylene-bridged sesquiterpenoid trimers possessing a unique C 46 skeleton, four carbon-bridged disesquiterpenoids with a C 33 or C 31 skeleton, and four disesquiterpenoid−geranylbenzofuranone conjugates. 10,11 The preliminary results showed that the ethanol extract from the roots of L. aggregata exhibited the transforming growth factor (TGF)-β inhibitory activity. Motivated by these findings, we performed a thorough phytochemical investigation into the ethanol extract of the roots of L. aggregata, resulting in the isolation and identification of 14 new lindenane sesquiterpenoid dimers (1−14) featuring an oxygen bridge (Figure 1).…”

Aggreganoids A–F, Carbon-Bridged Sesquiterpenoid Dimers and Trimers from Lindera aggregata

“…L. aggregata has been found to be a rich source of bioactive sesquiterpenoids, but only one dimeric sesquiterpenoid has been identified from this plant . In the course of our ongoing search for sesquiterpene hybrids from this plant, the ethanolic extract of the roots of L. aggregata was phytochemically investigated, resulting in the isolation and characterization of six unprecedented sesquiterpenoid trimers and dimers, aggreganoids A–F ( 1 – 6 ) (Figure ). Compounds 1 – 6 represent a new class of oligomeric sesquiterpenoids featuring the connection between different or identical sesquiterpenoid monomers via a carbon bridge.…”