Inhibition of glucose metabolism by n-hexadecane in Cladosporium (Amorphotheca) resinae

Abstract

When Cladosporium resinae is provided with n-hexadecane and glucose, nhexadecane is used preferentially. Studies using [14C]glucose indicated that nhexadecane did not inhibit glucose uptake but did retard oxidation of glucose to CO2 and assimilation of glucose carbon into trichloroacetic acid-insoluble material. Glucose could be recovered quantitatively from hydrocarbon-grown cells that had been transferred to glucose. Four enzymes that may be involved in glucose metabolism, hexokinase, glucose-6-phosphate dehydrogenase, glucosephosphate isomerase, and succinate dehydrogenase, were not detected in cells grown on hexadecane but were present in cells grown on glucose. Addition of hexadecane to extracts of glucose-grown cells resulted in immediate loss of activity for each of the four enzymes, but two other enzymes not directly involved in glucose metabolism, adenosine triphosphatase and alanine-ketoacid aminotransferase, were not inhibited by hexadecane in vitro. Cells grown on hexadecane and transferred to glucose metabolize intracellular hexadecane; after 1 day, activity of hexokinase, glucose-6-phosphate dehydrogenase, glucosephosphate isomerase, and succinate dehydrogenase could be detected and 22% of the intracellular hydrocarbon had been metabolized. Hexadecane-grown cells transferred to glucose plus cycloheximide showed the same level of activity of the four enzymes as cells transferred to glucose alone. Thus, intracellular nhexadecane or a metabolite of hexadecane can inhibit the activity of enzymes involved in glucose metabolism, but synthesis of those enzymes is not inhibited.

Assessment of antidiabetic potential and phytochemical profiling of Rhazya stricta root extracts

“…Moreover, Berberine, that is an Isoquinoline alkaloid isolated from Rhizoma coptidis has shown hypoglycemic and anti-dyslipidemic activities [58]. 12.332 n-Hexadecane P P Inhibition of enzymes involved in glucose metabolism [40] 12. 19.526 9-Octadecenoic acid (Z)-, methyl ester P P P P P P P P Antioxidant [42] 19.630 Hexadecane P 25.817 Phthalic acid, bis(7-methyloctyl) ester P P 26.081 Squalene P P P P P P Antidiabetic [45] Antioxidant [46] 26.328 Eburnamenine-14-carboxylic acid, 14,15-dihydro-14hydroxy-, methyl ester, (3.alpha.,14.alpha.,16.alpha.…”

“…After the initial screening, we have found a variety of the compounds of different phytochemical classes through GCMS. Interestingly, among the identified compounds in the SCL fraction, five have already been documented as antihyperglycemic compounds namely; Hexadecane [ 40 ], n-Hexadecanoic acid [ 41 ], Vinburnine, Vincamine [ 44 ] and Squalene [ 45 ]. Some other classes of compounds have also been identified and derivatives of which are reported of antidiabetic potential like Benzofuran [ 51 ], Quinoxaline [ 52 ] Quinoline [ 53 , 54 ], Pyridine [ 55 ], Sydnones [ 56 ] Thioureas [ 57 ] and Isoquinolines [ 58 ].…”