Related Experiment Video
Updated: Oct 11, 2025

A Customizable Approach for the Enzymatic Production and Purification of Diterpenoid Natural Products
Published on: October 4, 2019
Structures of ganorbifates C-I, seven previously undescribed lanostanoids from the mushroom Ganoderma orbiforme, and
Xia Yin1, Chao Yu1, Thi M L Tuong1
1Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, 3 Taicheng Road, Yangling, 712100, Shaanxi, China.
Abstract:
Ganorbifates C-I, seven undescribed biosynthetically related polyoxygenated 3,4-seco-27-norlanostanoid congeners, were isolated from the edible mushroom, Ganoderma orbiforme. Ganorbifate C features a unique cyclobutene ring constructed at C19/C11, and both D and E incorporate an unusual cyclopropane ring formed by C-19/C-9 linkage. Their structures, including the absolute configurations, were determined by spectroscopic methods and ECD calculations. The proposed Norrish-Yang cyclization-based key biosynthetic pathway for ganorbifates C-E is revealed by density functional theory (DFT) calculations. The computational studies uncover the formation of both cyclobutene and cyclopropane rings in the isolates and the stereoselectivity centers of these steps are consistent with those in the natural products. All compounds exhibited NO generation inhibition in LPS-induced BV-2 microglial cells, among them ganorbifate C was the most promising one with the IC50 values of 4.37 μM.
More Related Videos
Related Concept Videos
Stereoisomerism of Cyclic Compounds
Biosynthesis of Lipids
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
Structures of Carboxylic Acid Derivatives
Carboxylic acid derivatives contain an acyl group attached to a heteroatom such as chlorine, oxygen, or nitrogen. The carbonyl carbon and oxygen are both sp2-hybridized with an unhybridized p orbital.
The three sp2 orbitals of the carbonyl carbon form three σ bonds, one each with the carbonyl oxygen, the α carbon, and the heteroatom, whereas the other two sp2 orbitals of the carbonyl oxygen are occupied by the lone pairs. Further, the...
UV–Vis Spectroscopy: Woodward–Fieser Rules
Structure of Conjugated Dienes
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...

