Related Experiment Video
Updated: Apr 3, 2026

Transient Expression in Nicotiana Benthamiana Leaves for Triterpene Production at a Preparative Scale
Published on: August 16, 2018
Two Triterpenoids with a Cyclobutane Moiety from Mastic: Structural Elucidation and Biological Evaluation
Xue-Rui An1,2, Hong-Yi Wang3, Tian-Zhi Li2
1Key Lab of Natural Product Chemistry and Application at Universities of Education, Department of Xinjiang Uygur Autonomous Region, School of Chemistry and Chemical Engineering, Yili Normal University, Yining 835000, China.
Abstract:
Two novel triterpenoids, cyclobutastics A (1) and B (2), were isolated from mastic (Pistacia lentiscus L.). Their structures were fully elucidated by NMR, ACD/SE, QCC-NMR, and ECD analysis. Compound 1 is characterized by a rare cyclization that forms a cyclobutane via the connection between C-1 and C-11, resulting in a fused 6/6/4/6/5 pentacyclic framework. Compound 2 features an unprecedented cyclobutane formed by the C-8-C-18 linkage, marking the first report of this structural motif in a natural triterpenoid. Compound 2 inhibited the proliferation of human colorectal adenocarcinoma SW480 and HCT116 cells, with IC50 values of 15.2 ± 1.3 and 3.8 ± 0.7 μM, respectively, and exhibited moderate anti-inflammatory activity (IC50 = 24.7 ± 1.5 μM).
Related Concept Videos
Aromatic Hydrocarbon Cations: Structural Overview
Removing one hydrogen from the intervening CH2 group...
Conformations of Cycloalkanes
Mass Spectrometry: Cycloalkane Fragmentation
For example, cyclohexane molecular ions have a mass-to-charge ratio (m/z) of 84, which tends to produce a stronger signal than linear alkanes like hexane. This stability comes from...
Prochirality
Stability of Substituted Cyclohexanes
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
Criteria for Aromaticity and the Hückel 4n + 2 Rule
For the first time, Eric Hückel, a German chemical physicist, derived a set of structural features for a compound to be classified as aromatic. This is now known as Hückel’s rule or the 4n +...

