ABSTRACT
Purpurolides D-F (1-3), three new polyoxygenated bergamotanes bearing a 6/4/5/5 tetracyclic ring system, were isolated from the endophytic fungus Penicillium purpurogenum IMM 003. Their structures were unambiguously elucidated based on extensive spectroscopic data analyses, C NMR chemical shifts calculations coupled with the DP4+ probability method, and the calculated and experimental electronic circular dichroism (ECD) spectra. Compounds 1-3 showed significant inhibitory activity against pancreatic lipase (PL). The result highlights that the presence of 3-hydroxylated decanoic acid moiety at C-14 is important for increasing the inhibition potency against PL.
ABSTRACT
Ten Penicillium sp. were screened for lectin activity for occurrence of lectins. Mycelial extracts from submerged cultures of P. corylophilum, P. expansum and P. purpurogenum showed agglutination against human (A, B, AB and O), goat, sheep, pig and rabbit erythrocytes. Neuraminidase treatment to human blood type O erythrocytes substantially increased their agglutinability by all the lectins as compared to untreated erythrocytes. Modification of erythrocyte surfaces by protease increased the lectin titre only of P. corylophilum with no effect on other two lectins. P. corylophilum and P. expansum displayed relatively lower titres in mycelial extracts prepared from agar plate cultures as compared to broth cultures. A panel of sugars was tested for inhibition of lectin activity. All the lectins were found to be specific for asialofetuin, bovine submaxillary mucin, porcine stomach mucin, chondroitin-6-sulphate, D-sucrose and D-glucose. P. corylophilum lectin was expressed (Titre 8) by 5 day old cultures, reaching its maximum level (Titre 32) upon 8 days of cultivation, thereafter declin in lectin activity was observed. P. purpurogenum lectin was expressed by 7-10 days old cultures, while in P. expansum maximum lectin activity was elaborated by 5-8 days old cultures. Lectin extracts from all the three species were found to possess antimicrobial activities. Lectin extracts from the three Penicillium species displayed antifungal activity and antibacterial activity against Gram-negative and Gram-positive bacterial strains.
Subject(s)
Anti-Infective Agents/pharmacology , Hemagglutination Tests , Lectins/pharmacology , Microbial Sensitivity Tests , Penicillium/chemistry , Penicillium/classification , Species SpecificityABSTRACT
The effect of several nutritional and environmental parameters on Penicillium purpurogenum growth and sacharogenic amylase production was analyzed. High enzyme levels (68.2 U mg-1) were obtained with Khanna medium at initial pH 6.0, incubated at 30ºC for 144 hours. The optimum pH and temperature activities were 5.0 and 65ºC, respectively. The enzyme presented a half-life (t50) of 60 min, at 65ºC. Only glucose was detected after 24 hours of reaction using soluble starch as substrate.
Subject(s)
Amylases/analysis , Fermentation , Penicillium/enzymology , Enzyme Activation , Methods , MethodsABSTRACT
Objective: To investigate the antitumor metabolites of fungal mutants 2-2-3 and PDN-f-2, the two bioactive mutants of Penicillium purpurogenum G59 that do not produce antitumor metabolites. Methods: Bioactive metabolites newly produced by the mutants were isolated by a bioassay-guided separation procedure using iquid-liquid extraction, column chromatography and recrystallization methods through direct comparison with the sample from P. purpurogenum G59. The compounds obtained were identified by spectroscopic methods. The antitumor activity was assayed by the MTT method using K562 cells. Results: Two bioactive metabolites 1 and 2 were isolated from the fermentation products of 2-2-3 and PDN-f-2, respectively, and identified as ergone (1) and citrinin (2). Compounds 1 and 2 inhibited the proliferation of K562 cells with the IC50 values of 7. 4 and 48. 0 μg/ml, respectively. Conclusion: Compounds 1 and 2 are the antitumor metabolites newly produced by he mutants 2-2-3 and PDN-f-2, respectively, and have not been found in the metabolites of P. purpurogenum so far. It is revealed from the present result that the alteration of secondary metabolism of wild-type fungal strains without bioactivity for obtaining bioactive metabolite-producing mutants may become a new route to expand the source of new fungal strains for drug screening.