The World Botanical Associates Web Page
Prepared by Richard W. Spjut
May 2004, June 2015

Iris missouriensis

Collection of 73.5 pound sample (dry weight) for the National Cancer Institute by Richard Spjut as an employee of the USDA Agricultural Research Service, Economic Botany Laboratory, May 1981.  Chemical fractionation and isolation of the antitumor active chemical in the root sample was later carried out at the University of Illinois at Chicago under Dr. Norman Farnsworth.  Getting the root out of the ground was easy with the caterpillar. Removing dirt from the root, however, was time consuming. Collection was made in eastern Oregon on the private ranch of Jim Sphar who kindly donated his time and equipment to obtain the sample. 




Iris hartwegii

Kern Co.: California. S Sierra Nevada, east slopes of the Greenhorn Mts., Old State Rd, ponderosa pine woodland, 6,000 ft, CNPS Chapter Field Trip, 30 May 2015



Iris missouriensis

Nevada. Toiyabe Range, SE of Austin along FS Rd 003, 5.3 mi S of Hwy 50, T18N R44E Sec 5,; 3925.464, 11702.770, 7000 ft.  Meadow with high density stands of Veratrum californicum in valley running SE bordered by a closed canopy aspen forest and sagebrush on drier slopes. Shrub thickets include Rosa nutkana, Symphoricarpos oreophilus; and forbs Iris missouriensis, 10 July 2009


Iris purdyi
Oregon Mt., Weaverville, CA
Spjut & Casterline 15323,
May 2003




Iris setosa
Kenai Peninsula, AK
Spjut & Marin 15450,


USDA ARS Record of Procurement for Antitumor Active Species of Iris

Iris douglasii

Iris missouriensis

Iris virginica

Wong S. M., C. Konno, Y. Oshima, J. M. Pezzuto, H. H. Fong and N. R. Farnsworth 1987. Irisones A and B: two new isoflavones from Iris missouriensis. J. Nat. Prod. 50(2): 178180.  Two new isoflavones, irisones A and B, together with the known compound, 5,7-dihydroxy-2',6-dimethoxy isoflavone, were isolated from the roots of Iris missouriensis. With the help of 2D-homonuclear-J-correlation and 2D-nOe experiments the structure of irisone A was deduced to be 5-hydroxy-2'-methoxy-6,7-methylenedioxy isoflavone. The structure of irisone B was elucidated by spectral analyses as 2',5-dihydroxy-6,7-methylenedioxy isoflavone and was confirmed by chemical conversion to irisone A.

Wong S. M., J. M. Pezzuto, H. H. Fong and N. R. Farnsworth. 1986.  Isolation and characterization of a new triterpene from Iris missouriensis.  J Nat Prod. 49(2): 330333.

Wong S. M., J. M. Pezzuto, H. H. Fong and N. R. Farnsworth. 1986. Plant anticancer agents XXXIX: Triterpenes from Iris missouriensis (Iridaceae).  J Pharm Sci. 75(3): 317-320. Employing the roots of Iris missouriensis, two known triterpenes, iso-iridogermanal and zeorin, were isolated and identified. As presently reported, they were found to demonstrate cytotoxic activity toward cultured P-388 cells (ED50 = 0.1 and 1.1 microgram/mL, respectively). Additionally, a new triterpene that demonstrated an ED50 of 8.5 micrograms/mL was isolated. On the basis of spectral analysis and chemical correlation with zeorin, the structure was shown to be 6 6 alpha-hydroxy-A'-neogermmacer-22(29)-en-30-oic acid (missourin).

Wong S. M., J. M. Pezzuto, H. H. Fong and N. R. Farnsworth. 1985. Isolation, structural elucidation, and chemical synthesis of 2-hydroxy-3-octadecyl-5-methoxy-1,4-benzoquinone (irisoquin), a cytotoxic constituent of Iris missouriensis.  J. Pharm. Sci. ;74(10): 11141116. As part of a continuing effort to provide novel agents of potential value in cancer chemotherapy, 2-hydroxy-3-octadecyl-5-methoxy-1,4-benzoquinone (irisoquin) was identified as a component of Iris missouriensis. This novel species demonstrated cytotoxic activity with cultured KB and P-388 cells (ED50 = 1.8 and 0.03 microgram/mL, respectively). The structure was assigned on the basis of spectral analyses and The structure was assigned on the basis of spectral analyses and confirmed by chemical synthesis. The latter provides a facile method for the production of irisoquin and structural derivatives that may be of value for the examination of structure-activity relationships. A closely related compound, 3-octadecyl-5-methoxy-1,4-benzoquinone (deoxyirisoquin), was also isolated from Iris missouriensis, prepared synthetically, and found to be devoid of cytotoxic activity.