Molecular weight and protein-precipitating ability of condensed tannins from warm-season perennial legumes

Figures & data

Table 1. Legume condensed tannin constituents.

Plant	ECT	PBCT	FBCT	TCT	Mn	MW	PPP	PB	PB/PPP
Acacia angustissima var. hirta (STP5)^1	4.4^d	4.0^a	0.5^ab	8.9^b	1008	1064	87.8^e	65.6^d	0.75^bc
Acacia angustissima var. hirta (STX)^2	4.9^cd	3.3^ab	0.3^bc	8.5^b	1099	1132	118^d	73.7^bc	0.63^bc
Arachis glabrata	0.0^g	0.0^f	0.0^d	0.0^d	819	851	0.0^f	0.0^e	0.0^d
Desmanthus illinoensis	5.1^c	2.4^bc	0.6^a	8.1^b	840	866	54.1^f	75.3^bc	1.39^a
Desmodium paniculatum	10.3^a	2.0^cd	0.1^cd	12.5^a	583	1039	200^a	64.7^d	0.32^cd
Lespedeza cuneata	4.7^cd	3.4^a	0.1^cd	8.3^b	1276	1483	57.7^f	78.1^ab	1.36^a
Lespedeza stuevei	9.9^a	1.7^cde	0.1^cd	11.7^a	520	552	168^b	72.3^c	0.43^cd
Leucaena retusa	2.4^e	0.7^ef	0.2^cd	3.2^c	901	950	6.0^g	4.4^e	0.74^bc
Mimosa strigillosa	9.9^a	1.7^cd	0.2^cd	11.7^a	768	820	125^c	70.9^c	0.57^bc
Neptunia lutea	7.0^b	1.2^def	0.1^cd	8.3^b	1154	1179	82.0^e	80.0^a	0.98^ab
SEM	0.23	0.33	0.08	0.38			1.41	2.09	0.16

Note: Results are reported as %DM of purified CT based on a unique calibration curve prepared for each species using purified CT from that species.

ECT, extractable condensed tannins; PBCT, protein-bound condensed tannins; FBCT, fiber-bound condensed tannins; TCT, total condensed tannins; condensed tannin molecular weights (M_n, number-average molecular weight; M_W, weight-average molecular weight), and condensed tannin protein precipitability (PPP: protein-precipitable phenolics, g/kg DM; PB: amount of protein bound, g/kg DM; PB/PPP: ratio of protein bound to protein-precipitable phenolics) from warm-season perennial legumes.

¹STP5: cross-timbers ecotype.

²STX: South Texas ecotype.

^a–gWithin a column, least squares means without a common superscript differ (P ≤ 0.05).

Figure 1. Correlations between weight-average molecular weight (CT M_W) of condensed tannins from warm-season perennial legumes. (a) Protein-precipitable phenolics (PPP g/kg DM), (b) amount of protein bound by protein-precipitable phenolics (PB g/kg DM), and (c) amount of protein bound (g) per g of protein-precipitable phenolics (PB/PPP).

Figure 2. Correlations between total condensed tannin concentration (% TCT) on a DM basis of warm-season perennial legumes. (a) Protein-precipitable phenolics (PPP g/kg DM), (b) amount of protein bound by protein-precipitable phenolics (PB g/kg DM), and (c) amount of protein bound per g of protein-precipitable phenolics (PPP/PB).