Acidolysis and hot water extraction provide new insights into the composition of the induced "lignin-like" material from squash fruit

Accumulation of "lignin-like" material (L-LM) by plant tissues in response to injury or disease has been observed in a wide variety of plant taxa. The most intensively studied L-LM is that produced by members of the Cucurbita ceae: this material is thought to he an unusual lignin rich in p-coumaryl a lcohol derived subunits. Employing acidolysis we found the primary degradat ion product of L-LM from squash fruit was p-coumaryl aldehyde. These findin gs conflict with the: current concept of L-LM. but would be consistent with L-LM being a polymer derived directly from p-coumaryl aldehyde or a gum co ntaining this compound. Results of hot water extraction support the latter possibility. Further, we report on a simple TLC method useful for rapid qua litative characterization of acidolysis degradation products. (C) 2001 Else vier Science Ltd. All rights reserved.