1. Department of Natural Sciences, Northeastern State University, Tahlequah, OK, USA,
2. Department of Chemistry and Biochemistry and The Institute of Biomedical Studies, Baylor University, Waco, TX, USA,
3. Department Chemistry and Biochemistry, McMurry University, Abilene, TX, USA, and
4. Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, USA