5,7-Dihydroxy-4a,9-dimethyl-3-methylidenedecahydrofuro[2',3':5,6]cyclohepta[1,2-c]pyran-2(3h)-one

Oral LD50 (mouse) = 150 mg/kg; [RTECS] Lethal to sheep at doses of 100 mg/kg; Toxic action may be due to alkylating sulfhydryl groups of enzymes in the body; Emergency treatment: Plants- sesquiterpene lactones; Sesquiterpene lactones are in many plants. They cause toxicity mainly in livestock that eat the plants. Human poisoning cases are extremely rare. Possible symptoms after ingestion include irritation of mucous membranes, dyspnea, pulmonary hemorrhage, tremors, seizures, abdominal pain, and liver injury. [HSDB] Sesquiterpene lactones are a common cause of allergic dermatitis in florists. See Sesquiterpene lactones.

HYMENOVIN, A SESQUITERPENE LACTONE PREVIOUSLY REPORTED AS THE MAJOR TOXIC CONSTITUENT OF HYMENOXYS ODORATA, WAS ISOLATED FROM EXTRACTS OF HYMENOXYS RICHARDSONII AND DUGALDIA HOOPESII AND WAS SHOWN TO ACCOUNT FOR THE TOXICITY OF THESE PLANTS AS WELL. THE FINDING THAT THESE 3 POISONOUS RANGE PLANTS CONTAIN AN IDENTICAL TOXICANT IS CONSISTENT WITH PRIOR OBSERVATIONS OF VERY SIMILAR RESPONSES IN LIVESTOCK POISONED WITH THE WHOLE PLANTS.

HYMENOVIN RETAINED 41% OF ITS MUTAGENIC POTENCY TO SALMONELLA TYPHIMURIUM TA100 AFTER HYDROGENATION OF THE EXO-METHYLENE PORTION OF THE ALPHA-METHYLENE-GAMMA-LACTONE MOIETY, BUT LESS THAN 3% AFTER DIETHYLATION OF THE BISHEMIACETAL MOIETY. APPARENTLY, THE PRINCIPAL REACTIVE SITE RESPONSIBLE FOR THE MUTAGENICITY IS THE BISHEMIACETAL MOIETY AND NOT THE ALPHA-METHYLENE-GAMMA-LACTONE MOIETY.

IN VITRO HYMENOVIN AT 0.6 MG/ML INHIBITED THE GROWTH OF BACILLUS THURINGIENSIS BY 98%. HYMENOVIN HAD A MUTAGENIC EFFECT ON B THURINGIENSIS CULTURES, RESULTING IN THE PRODUCTION OF SEVERAL VARIENT STRAINS. SOME OF THE VARIENT STRAINS LOST THEIR ABILITY TO FORM SPORES AND CRYSTALS. HYMENOVIN ALSO INDUCED B THURINGIENSIS TO PRODUCE SIGNIFICANT LEVELS OF BACTERIOPHAGE. ALL VARIENT STRAINS WERE AS SUSCEPTIBLE TO PHAGE AS THE PARENT STRAIN.

HYMENOVIN IS A MIXTURE OF EPIMERIC DIHEMIACETALS AND IS LETHAL TO SHEEP WHEN GIVEN ORALLY AT LEVELS AS LOW AS 100 MG/KG. HYMENOVIN PROBABLY EXERTS ITS TOXIC ACTION, AT LEAST IN PART, BY ALKYLATING SULFHYDRYL GROUPS OF KEY ENZYMES AND OTHER BODY CONSTITUENTS.

Toxic component of the poisonous range plant Hymenoxys odorate; [ChemIDplus] A sesquiterpene lactone; Also found in 2 poisonous range plants: Hymenoxys richardsonii (Pingue) and Dugaldia hoopesii (orang sneezeweed); A major constituent of western bitterweed (Hymenoxys odorata DC); [HSDB]