Abstract:
The Department of Chemistry at Missouri State University-West Plains (MSU-WP) is
internationalizing the existing research activities by initiating a collaborative Kenya-U.S. Chiral Science
(chiroscience) project. The overarching goal of the project is three-fold: 1) reinvigorate undergraduate research;
2) augment MSU-WP’s new Green Nanoscience Research and Mentoring Program; and 3) establish synergistic
relationships between different research groups and academic institutions in Kenya and MSU-WP. To stimulate
students’ interests in the collaborative chiroscience project, we have chosen projects that are not only aligned
with NSF’s high priority areas but are also relevant to today’s society (e.g., cancer, tuberculosis, heart disease,
HIV, and host-guest chemistry). For several years, our research groups have been working on two important
supramolecular hosts, calixarenes and cyclodextrins (CDs). Calixarenes are macrocyclic structures with defined
cavities, having host-guest complexation properties similar to CDs. One of the advantages that calixarenes have
over naturally occurring host molecules, such as CDs, is that the size of the internal cavity of the macrocycle is
more flexible, i.e., the number of constituent rings range from four to eight. This paper illustrates our ongoing
efforts in the area of synthesis and complexation properties of calixarenes. Herein, we report the synthesis of new
amino acid-based acylcalixarenes and characterization by means of 1
H- and 13C-NMR spectroscopy. The
calix[4]arenes possess L-alanine, L-valine, L-leucine, and L-isoleucine moeties at the lower rim. 1D and 2D
NMR showed that the new calixarenes adopt the standard “cone” conformations in solution.
