Polygonum sachalinense

Two naphthoquinones, emodin (65) and physcion (66), and their glucosides were identified as allelochemicals from the rhizomes, aerial parts, and fallen leaves of giant knotweed (Polygonum sachalinense Fr. Schm.).7 In addition, the concentrations of emodin and physcion in the soil samples collected from the weed community were high enough to suppress seedling growth of susceptible plant species. 

H. Nishimura J. Mizutani, Identification of Allelochemicals in Eucalyptus citriodora and Polygonum sachalinense. In Allelopathy Organisms, Processes, and Applications, Inderjit, K. M. M. Dakishini, F. A. Einhellig, Eds. American Chemical Society Washington, DC, 1995 pp 74-85. 

The Fallopia japonica var compacta examined were either male-sterile or female-sterile. The introduction of new species was limited to the genetic base of the fertile hybrid progeny. Some hybrids were sterile, while some had low fertility (e.g. the hybrid between Polygonum cuspidatum, also known as Fallopia japonica and Polygonum sachalinense, also known as Fallopia sachalinensis yields a hexaploid). 

Plant materials were collected in and around Sapporo during the summer months. For the screening test, 10 g (fresh weight) of the aerial parts (mainly leaves/stems) were immersed in 150 ml of MeOH for 3-4 days at room temperature. The resulting extract was then reduced to dryness and the residue was partitioned between EtOAc and water. In order to isolate and characterize the antidotes, Polygonum lapathifolium L. subsp. nodosum, P. sachalinense Fr. Schm. and P. thunbergii were collected in large quantities and extracted with MeOH. 

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