Dinobuton

TERRESTRIAL FATE: Based on a recommended classification scheme(1), an estimated Koc value of 6800(SRC), determined from a structure estimation method(2), indicates that Dessin will be immobile in soil(SRC). Dessin may biodegrade under anaerobic conditions; in ruminal fluid, this compound was rapidly degraded(3). In alkaline water, this compound should hydrolyze to dinoseb(4). Volatilization of Dessin is not expected from moist soil surfaces(SRC) given an estimated Henry's Law constant of 1.6X10-8 atm-cu m/mole(SRC), using a recommended regression equation(5). Volatilization should not occur from dry soil surfaces(SRC), based on an estimated vapor pressure of 1.1X10-6 mm Hg(SRC), determined from a fragment constant method(6). Photodegradation of Dessin on soil surfaces may occur; dessin, exposed to sunlight on bean foliage, formed several degradation products(7).

AQUATIC FATE: Based on a recommended classification scheme(1), an estimated Koc value of 6800(SRC), determined from a structure estimation method(2), indicates that Dessin should adsorb to suspended solids and sediment in water(SRC). Dessin may biodegrade under anaerobic conditions; in ruminal fluid, this compound was rapidly degraded(3). In alkaline water, this compound should hydrolyze to the parent compound, dinoseb(4). Dessin is not expected to volatilize from water surfaces based on an estimated Henry's Law constant of 1.6X10-8 atm-cu m/mole(SRC), developed from a fragment constant estimation method(5). An estimated BCF value of 580(1,SRC), from an estimated log Kow(6,SRC), suggests that Dessin will bioconcentrate in aquatic organisms(SRC), according to a classification scheme(7).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), Dessin, which has an estimated vapor pressure of 1.1X10-6 mm Hg at 25 °C(2,SRC), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase Dessin is degraded in the atmosphere by reaction with photochemically produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be about 2 days(3,SRC). Particulate-phase Dessin may be physically removed from the air by dry deposition(SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc for Dessin can be estimated to be about 6800(SRC). According to a recommended classification scheme(2), this estimated Koc value suggests that Dessin will be immobile in soil(SRC).

STATE OF IMMUNOLOGICAL REACTIVITY IN 70 FEMALE HOTHOUSE WORKERS WITH PROLONGED EXPOSURE TO PESTICIDES WAS EVALUATED. ANALYSIS OF INDICES OF NONSPECIFIC IMMUNITY SHOWED INCR MICROBIAL DISSEMINATION OF THE SKIN. THE DEGREE OF DISSEMINATION WAS CORRELATED WITH DURATION OF EXPOSURE TO PESTICIDES. WORKERS WITH OVER 2 YR EXPOSURE HAD SIGNIFICANTLY DECR PHAGOCYTIC ACTIVITY OF NEUTROPHILS. SPECIFIC INCR OF BLAST TRANSFORMATION OF PERIPHERAL BLOOD LYMPHOCYTES IN RESPONSE TO ACREX (DINOBUTON) WAS DETECTED IN 47-52% OF WORKERS WITH OVER 5 YR EXPOSURE. GENERAL MORBIDITY INCREASED WITH INCREASE OF DURATION OF EXPOSURE: ALLERGIC SKIN DISEASES WERE MORE FREQUENT AMONG WORKERS WITH 1-5 YR EXPOSURE, WHILE BRONCHIAL ASTHMA, LIVER & KIDNEY DISEASES WERE MORE FREQUENT AMONG WORKERS WITH OVER 5 YR EXPOSURE.

Dessin, was rapidly metabolized when incubated with bovine ruminal fluid. Metabolites tentatively identified were 2-amino-6-sec-butyl-4-nitrophenol and the 2,4-diamino-6-sec-butylphenol. The latter compound apparently is the end product of the ruminal metabolism of dessin(1).

An estimated BCF value of 580 was calculated for Dessin(SRC), using an estimated log Kow of 3.94(1,SRC) and a recommended regression-derived equation(2). According to a classification scheme(3), this BCF value suggests that bioconcentration in aquatic organisms is high(SRC).

The Henry's Law constant for Dessin is estimated as 1.6X10-8 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This value indicates that Dessin will not volatilize from water surfaces(2,SRC). Dessin's estimated values for vapor pressure, 1.1X10-6 mm Hg(3,SRC) and Henry's Law constant(1,SRC) indicate that volatilization from dry and moist soil surfaces should not occur(SRC).

MAX 'NO EFFECT' LEVEL FOR DOGS IS 4.5 MG/KG DAILY, FOR RATS 3-6 MG/KG DAILY. IT ACTS AS METABOLIC STIMULANT, HIGH DOSES CAUSING LOSS OF BODY WT.

PROLONGED FEEDING OF ACREX (FODDER CONTAINING 30% EMULSIFIABLE CONCN FOR 2 MO TO SHEEP; DAILY DOSE OF 35 MG/KG-GROUP 1, 16.6 MG/KG-GROUP 2, OR 8.3 MG/KG-GROUP 3) INDUCED HYPEREMIA OF ORAL MUCOSA, SPLOTCHY LIVER COLORING, CATARRHAL INFLAMMATION OF STOMACH & INTESTINE, HEMORRHAGIC FOCI IN HEART MUSCLE, & ATRIAL HYPOTROPHY. EXPOSURE ALSO RESULTED IN DECR OF RED BLOOD COUNT & TOTAL PROTEIN IN BLOOD SERUM.

The rate constant for the vapor-phase reaction of Dessin with photochemically-produced hydroxyl radicals has been estimated as 7.3X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1,SRC). This corresponds to an atmospheric half-life of about 2 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1,SRC). Anthraquinone enhanced the photodegradation of dessin(2). Bean leaves sprayed with both rotenone and Dessin and then exposed to sunlight for 1 hour gave a 14-C-dessin recovery of 80.8, 67.2, and 29.9% at rotenone concentrations of 0, 10, and 100 ppm, respectively; this suggests that rotenone may act as a photosensitizer to Dessin(3). Dessin, exposed to sunlight on bean foliage, formed several degradation products including dinoseb, one unknown ester and two unknown phenol compounds(4). This compound decomposes under alkaline conditions to dinoseb(5).