Tumor inhibitors. LXVII. Eupacunin, a novel antileukemic sesquiterpene lactone from Eupatorium cuneifolium

Kupchan, S. Morris; Maruyama, Megumi; Hemingway, R.J.; Hemingway, J. C.; Shibuya, S.; Fujita, Takashi; Cradwick, P. D.; Hardy, Andrew; Sim, G. A.

doi:10.1021/ja00748a048

Cited by 42 publications

(11 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…§ To whom reprint requests should be addressed. deca-1,5-dienes (IV) and is not yet represented by a natural product, although eupacunin (13) and liatrin (14) seem to be biogenetic derivatives of this group. From inspection of Dreiding models, the cis,cis-germacranolide sesquiterpene lactones are expected to adopt a conformation with CA14 and CA15 both a to the plane of the medium ring, as indicated in VIII.…”

Section: Figmentioning

confidence: 99%

Neutron Diffraction Structure of Melampodin: Its Role in the Reclassification of the Germacranolides

Watkins

Fischer

Bernal

1973

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The precise crystal and molecular structure of melampodin, C 21 H 24 O 9 , was determined from three-dimensional neutron diffraction data collected by counter techniques and phases by direct statistical methods. Crystals are orthorhombic, P2 1 2 1 2 1 , a = 8,990(9), b = 14.352(14), c = 16.294(16) Å, V = 2102 Å 3 , d(calc.) = 1.328 g·cm -3 , Z = 4 molecules per unit cell. The structural model was refined by full matrix least-squares of 2303 observed independent reflections, with all 54 atoms treated anisotropically, to R(F) = 5.0%. Hydrogen bonds link melampodin molecules together in the solid state. The conformation of the cyclodeca-1,5-diene ring is such that one intraannular hydrogen atom interacts strongly with one double bond, but there is little or no transannular interaction between double bonds. Strain in the ten-membered ring and in the trans -fused lactone ring is discussed, as are chemical implications of the unsymmetric epoxide in the epoxyangelic acid side chain. The previously suggested reclassification of germacranolide sesquiterpene lactones into four subgroups is supported, and a new convention for configurational representations of the four subgroups is proposed.

show abstract

Section: Figmentioning

confidence: 99%

Neutron Diffraction Structure of Melampodin: Its Role in the Reclassification of the Germacranolides

Watkins

Fischer

Bernal

1973

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Likewise, the analysis of above-ground parts of E. semiserratum DC collected from south of Bloutstown, Calhoun Co., Florida gave antileukemic germacrdienolide desacetyleupaserrin and flavones eupatorin, pectolinarigenin, hispidulin and salvigenin (Herz et al, 1981;Kupchan et al, 1973a). Tumor inhibiting sesquiterpene lactones including eupacunin have also been reported from E. cuneifolium (Kupchan et al, 1971;1973b). E. hyssopifolium contains the sesquiterpene lactone eupahyssopin which has immunostimulating, anti-inflammatory and cytotoxic activities (Wagner, 1984;Hall et al, 1979;1980, Lee et al, 1976.…”

Section: Bioactive Constituentsmentioning

confidence: 95%

A review of the toxicosis and biological properties of the genus Eupatorium

et al. 1998

View full text Add to dashboard Cite

Eupatorium genus grows wild in many parts of the world. A number of species of Eupatorium are toxic to grazing animals. Milk sickness in humans is caused by ingestion of milk of the animals reared on the pastures infested with Eupatorium rugosum (white snakeroot). While some information is available on the toxins in various species of Eupatorium, ambiguities still persist in extrapolation of the data to field incidence of toxicosis. Eupatorium genus has been used for its medicinal properties for many decades. A number of bioactive natural products have been reported in the extracts of Eupatorium spp. and the genus is a promising bioresource for preparation of drugs and value-added products.

show abstract

“…eupaformin (98),''' many heliangolides are functionalized in such a way so as to produce bridged hemiacetal linkages, e.g. woodhousin (99) However, centaurepensin is identical" with chlorohyssopifolin A (113)124 which must have the absolute configuration shown since it has been converted to 114, a derivative of cynaropicrin (115) whose absolute stereochemistry at the important centers has been established by correlation with o-santonln.!" The cause of the discrepancy is mysterious and needs to be investigated.…”

Section: Absolute Configurationmentioning

confidence: 99%