Isolation of Sesamin from Consumer Goods and Investigation of Its Acid-Catalyzed Epimerization: An Introductory Organic Lab Experiment Combining Natural Product Isolation and Spectral Analysis

Abstract

The pharmacologically active lignans sesamin and sesamolin are minor components of sesame oil and ingredients in OTC dietary supplement capsules. We report an introductory undergraduate organic laboratory experiment combining natural product isolation and spectral analysis in which students isolate a mixture of sesamin and sesamolin by either (1) dry column vacuum chromatography (a convenient alternative to flash column chromatography) of commercial sesame oil using an apparatus constructed from common laboratory glassware or by (2) solid−liquid extraction of commercial sesame seed lignan dietary supplement capsules. Two recrystallizations from methanol remove most of the sesamolin to afford crystalline sesamin, which, due to its 2fold rotational symmetry, students can easily identify and characterize by NMR. During a second laboratory period, students perform a 5 min, test tube-scale reaction of sesamin with catalytic BF 3 :OEt 2 to promote its epimerization to episesamin, a diastereomer of sesamin lacking rotational symmetry, and the sesamin/episesamin ratio in the resulting product mixture is established by 1 H NMR integration. Students are asked to propose a mechanism for this epimerization based on their knowledge of the reactivity of benzyl ethers under acidic conditions.

From Waste Paper to Cellulose: Building Environmental Awareness by Chemical Technology from Pragmatistic Pedagogy

“…This can not only help students consolidate theoretical knowledge and exercise their hands-on operation ability but also help to cultivate their awareness of environmental protection. 9,10 As a new type of material, thermal management materials mainly rely on conduction and radiation to complete the temperature control; they have the characteristics of requiring no energy input and being able to accurately adjust the microenvironment temperature of the system. 11−13 Meanwhile, the materials can effectively reduce the use of air conditioners and have been proved to have great application prospects in the fields of environmental protection and resource conservation.…”

“…Therefore, it is necessary for cellulose to be included in undergraduate chemistry experiments, and the effective recycling of waste paper can also be integrated into chemistry education through experiments. This can not only help students consolidate theoretical knowledge and exercise their hands-on operation ability but also help to cultivate their awareness of environmental protection. , …”