Molecules 2014, 19, 7990-8010; doi:10.3390/molecules19067990 OPEN ACCESS molecules ISSN 1420-3049 www.mdpi.com/journal/molecules Article Polymerization Degrees, Molecular Weights and Protein-Binding Affinities of Condensed Tannin Fractions from a Leucaena leucocephala Hybrid Mookiah Saminathan 1, Hui Yin Tan 2, Chin Chin Sieo 1,3, Norhani Abdullah 3,4, Clemente Michael Vui Ling Wong 5, Emilia Abdulmalek 6 and Yin Wan Ho 1,* 1 Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; E-Mails:
[email protected] (M.S.);
[email protected] (C.C.S.) 2 Faculty of Applied Sciences and Computing, Tunku Abdul Rahman University College, 53300 Kuala Lumpur, Malaysia; E-Mail:
[email protected] 3 Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; E-Mail:
[email protected] 4 Institute of Tropical Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia 5 Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia; E-Mail:
[email protected] 6 Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; E-Mail:
[email protected] * Author to whom correspondence should be addressed; E-Mail:
[email protected]; Tel.: +603-8947-2161; Fax: +603-8947-2101. Received: 18 March 2014; in revised form: 11 May 2014 / Accepted: 21 May 2014 / Published: 12 June 2014 Abstract: Condensed tannins (CTs) form insoluble complexes with proteins and are able to protect them from degradation, which could lead to rumen bypass proteins. Depending on their degrees of polymerization (DP) and molecular weights, CT fractions vary in their capability to bind proteins.