Effects of cassava cyanoglucoside, linamarin, on blood sugar levels in the dog

This study was undertaken to examine the diabetogenicity of linamarin in dogs of different nutritional status. The total dog population was 35; 15 normals, 10 undernourished, and 10 recovered. The recovered dogs were the refed undernourished dogs, On each dog a fasting plasma insulin and insulin receptor studies were done, followerd by a controlled glucose tolerance test. After feeding linamarin. 0.5 hour was allowed to elapse before these investigations were repeated. In the linamarin-treated udernourished animal, plasma insulin and insulin binding to erythrocytes and mononuclear leucocytes were significantly (P> 0.01) lower than in the control animals, and this resulted in abnormally high glucose levels. Linamarin administration had no effect on plasma insulin, insulin binding, or blood sugar levels in the normal and recovered dogs. These results point to the possible aetiology of diabetes in the undernourished state by 'toxic' foods substances such as linamarin. (AU)

Clinical and biochemical features of malnutrition related diabetes mellitus

The aims of this study were to characterize clinically and biochemically malnutrition related diabetes mellitus (MRDM) as it presents in Jamaica (J-type or phasic insulin dependent diabetes mellitus) and to examine the food toxin (linamarin)/malnutrition hypothesis as a possible aetiological factor in the onset of MRDM. The study was broadly divided into two major areas: (i) Clinical or patient study and (ii) Animal model study. The patient population consisted of thirty-four, (23 females, 17 males) who attend the Diabetic Outpatient Clinic of the University Hospital of the West Indies. This group consisted of 14 phasic insulin dependent diabetes mellitus (PIDDM) (8 females, 6 males) 10 non-insulin dependent diabetes mellitus (IDDM), (6 females, 4 males). Ten (10) normal (4 females, 6 males) subjects also participated. The diabetic and normal subjects were matched for age, body mass index and duration of diabetes (among diabetics). Comparitive studies were performed on insulin receptor binding, hormonal profile, glucose tolerance, blood status, renal, hepatic and pancreatic function. The results show a significantly decreased white and red blood cell binding to insulin (P<0.05), extensive kidney damage (P<0.05) and increased pancreatic echogenicity in PIDDM. These findings support a separate identity of the latter syndrome from Types 1 and 11 diabetes mellitus. In the animal model study, the dogs (male and female) were maintained on a diet of cornmeal cooked with chicken, fortified with Purina laboratory chow and water ad libitum. Malnutrition was induced by restricting the diet to a very small quantity of cornmeal only for a period of 7-10 days. The recovered dogs were re-fed the normal diet with added milk and multi-vitamin supplement. Linamarin dosage of 20 mg per kg body weight induced abnormally high glucose levels, and in two cases the hyperglycaemia was sustained for several days. There was an associated decrease in binding of insulin to erythrocytes and mononuclear leucocytes, as well as prevailng hypoinsulinaemia in the limarin-induced hyperglycaemic conditions. This animal study presents a possible aetiological model for malnutrition related diabetes mellitus (Summary)

The synthesis of heterocyclic compounds of pharmaceutical interest from conjugated acetylenic and allenic nitriles

The reaction of hydroxyacetylenic nitriles with 2-aminoethanethiol gives 3-(2-aminoethylthio)-4-hydroxy-alkyl-2-enenitriles. These do not cyclise directly to a furan but isomerise directly to the corresponding N-adducts which then cyclise to give 5-amino-3-(2-thioethylamino)-2,2-dialkyl-2,3-dihydrofurans in > 90 percent yield. After protecting the hydroxyl function of a 3-(2-aminoethylthio)-4-hydroxyalkyl-2-enenitrile as a tetrahydropyranyl derivative, this S-adduct isomerised to the corresponding N-adduct on keeping. Three new 5,6-dihydro-3H-furo [3,4-b]-1,4-thiazines were prepared from the 5-(1-alkyl-1-tetrahydropyranyl-oxyalkyl)-6-cyano-2,3-dihydro-4H-1,4-thiazines by hydrolysis to the corresponding 5-(1-hydroxyalkyl)-6-cyano-2,3-dihydro-1,4-thiazines followed by base catalysed cyclisation. The addition of half molar amounts of a-phenylethylamine to two allenic nitriles resulted in the isolation of recovered allenic nitrile with low optical purity. In both cases the absolute configuration of the recovered allene was related to that of the resolving agent(Summary)