(±)-Usphenethylones A−C, three pairs of heterodimeric polyketide enantiomers from Aspergillus ustus 3.3904

Three pairs of novel heterodimeric polyketide enantiomers, (±)-usphenethylones A−C (1−3), were isolated from the culture extract of Aspergillus ustus 3.3904. Compounds 1−3 represent two unique heterodimerization patterns of a phenethyl...

Benzoyl ester formation in Aspergillus ustus by hijacking the polyketide acyl intermediates with alcohols

Accumulation of two benzoyl esters in Aspergillus ustus after feeding with alcohols was reported 30 years ago. To the best of our knowledge, the biosynthesis for these esters has not been elucidated prior to this study. Here, we demonstrate that these compounds are artifical products of the phenethyl polyketide ustethylin A biosynthestic pathway. In addition, four aditional benzoyl esters with different methylation levels were also isolated and identified as shunt products. Feeding experiments provided evidence that the enzyme-bound polyketide acyl intermediates are hijacked by externally fed MeOH or EtOH, leading to the formation of the benzoyl esters. Graphic abstract

Anti-Fungal Activity of Cressa cretica, Leptadenia pyrotechnica and Pulicaria crispa, indigenous plants of Cholistan desert, Pakistan

Background: Fungal infections have always remain a problem and they are getting worse with passage of each year due to their resistance against available antibiotics. Natural ways of treatment with homoeopathic medicines made of mother tinctures of plants have no reported side effects and have been proved effective against many bacterial and fungal infections. Materials & Methods: Preparation of mother tinctures of plants Cressa cretica, Leptadenia pyrotechnica and Pulicaria crispa was done and used to evaluate the anti-fungal potential of these plants against potentially pathogenic fungal species like Aspergillus niger, Aspergillus flavus, Aspergillus ustus and Candida albicans by agar disc diffusion method. Each tincture was evaluated at 0.25 ml, 0.5 ml and 1 ml volume per disc and zone of inhibition was measured in millimetres and compared with commercial drug Fluconazole (2 mg/ml) which was used as standard. Results: The results showed that satisfactory anti-fungal activity of these plants in comparison to standard drug Fluconazole. The ratio of antifungal activity of Cressa cretica measured as the zone of growth inhibition of these cultures against Aspergillus niger, Aspergillus flavus, Aspergillus ustus and Candida albicans was 24 mm / 27 mm, 30mm / 28 mm, 23 mm/ 30 mm and 32 mm/ 30 mm respectively. In the case of Leptadenia pyrotechnica, the mother tincture’s antifungal activity was 32 mm / 27 mm, 30 mm / 28 mm, 17 mm/ 30 mm and 24 mm/ 30 mm. In case of our third plant Pulicaria crispa, antifungal activity came out to be 23 mm/ 27 mm, 26 mm/ 28 mm, 26 mm / 30 mm and 24 mm/ 30 mm. Conclusion: Our study proved that mother tincture of these plants can be a potential new therapy to treat fungal infections and has the potential to rule out fungal problems. Further research using mother tincture of these plants against other fungal species has the potential to prove them a safer and widespread anti-fungal homoeopathic medicine.