Department of Chemistry, University of Alaska, 99775-0520, Fairbanks, Alaska.
J Chem Ecol. 1990 Aug;16(8):2381-92. doi: 10.1007/BF01017463.
Condensed tannins were isolated from bitterbnish (Purshia tridentata) and blackbrush (Coleogyne ramosissima). Structural analyses showed that both tannins were procyanidins of similar polymer length. The overall stereochemistries at C-3 and C-4, however, differed between the two tannins. These changes in stereochemistry resulted in blackbrush tannins being less preferred than bitterbrush tannins when offered to snowshoe hares (Lepus americanus). It is unlikely that differences in protein-precipitating abilities are the cause for the preference of the bitterbrush over the blackbrush tannins. Instead, we hypothesize that condensed tannins may be depolymerized and absorbed following ingestion. Differences in tannin structure can lead to different depolymerized products and rates of depolymerization, both of which may affect herbivore preferences.
缩合单宁从苦木（Purshia tridentata）和黑brush（Coleogyne ramosissima）中分离得到。结构分析表明，这两种单宁都是原花青素，聚合物长度相似。然而，在两种单宁之间，C-3 和 C-4 的整体立体化学结构不同。这些立体化学结构的变化导致当向雪鞋兔（Lepus americanus）提供时，黑brush 单宁不如苦木单宁受欢迎。不太可能是蛋白质沉淀能力的差异导致了对苦木单宁的偏好超过了黑 brush 单宁。相反，我们假设缩合单宁可能在摄入后解聚和吸收。单宁结构的差异会导致不同的解聚产物和解聚速率，这两者都可能影响食草动物的偏好。
