A novel and safe essential amino acid (Leucine) incorporating sulfanilamide was synthesized, and evaluated for its anti-ulcerogenic activity and in vitro anti-Helicobacter pylori activity. The new molecule showed a dose dependent activity against absolute ethanol-induced ulcer in rats, it produced percent protection of control ulcer by 66.7 at dose 100mg/kg. In addition it showed a potent anti-Helicobacter pylori activity in vitro against 7 clinically isolated strains. The minimum inhibitory concentration (MIC) ranged from 12.5 to 50μg/ml. The preliminary safety studies and toxicity profile are optimistic and encouraging.

A library of 53 benzimidazole derivatives, with substituents at positions 1, 2 and 5, were synthesized and screened against a series of reference strains of bacteria and fungi of medical relevance. The SAR analyses of the most promising results showed that the antimicrobial activity of the compounds depended on the substituents attached to the bicyclic heterocycle. In particular, some compounds displayed antibacterial activity against two methicillin-resistant Staphylococcus aureus (MRSA) strains with minimum inhibitory concentrations (MICs) comparable to the widely-used drug ciprofloxacin. The compounds have some common features; three possess 5-halo substituents; two are derivatives of (S)-2-ethanaminebenzimidazole; and the others are derivatives of one 2-(chloromethyl)-1H-benzo[d]imidazole and (1H-benzo[d]imidazol-2-yl)methanethiol. The results from the antifungal screening were also very interesting: 23 compounds exhibited potent fungicidal activity against the selected fungal strains. They displayed equivalent or greater potency in their MIC values than amphotericin B. The 5-halobenzimidazole derivatives could be considered promising broad-spectrum antimicrobial candidates that deserve further study for potential therapeutic applications.

The cellular amino acid profiles of nine species of Fusarium; namely, Fusarium anthophilum, Fusarium avenaceum, Fusarium cerealis, Fusarium graminearum, Fusarium graminum, Fusarium oxysporum f. sp. conglutinans, Fusarium pseudograminearum, Fusarium roseum, and Fusariumsacchari var. elongatum growing on malt extract medium were determined. The amino acid profiles of the investigated fungi were varied and could be used for identification and characterisation of certain Fusarium species. Addition of certain chemical compounds including aspartic acid, glutamic acid, methionine, selenium, and urea to the growth medium affected the amino acid profiles. However, susceptibility of amino acid content to environmental conditions increased the variation of amino acid profiles among all the investigated Fusarium species. Some amino acids were only produced when certain chemical compounds were added to the growth medium. Valine was produced by F. anthophilum only in the presence of aspartic acid or selenium, while serine was produced in the presence of aspartic acid, glutamic acid, or methionine. Also, cysteine was produced by F. avenaceum in the presence of glutamic acid or urea. F. cerealis produced tryptophan only in the presence of aspartic acid or urea, while F. graminearum produced leucine in glutamic, methionine or urea. Similarly, many different amino acids were produced by each Fusarium species only in the presence of certain chemical compounds. The results revealed that the amino acid profiles will be more useful for characterisation and identification of fungi if they are determined under different conditions.

The ability of three fungal species, Cunninghamella blakesleeana, Cunninghamella homothallica, and Cunninghamella elegans to grow in the presence of different concentrations of radioactive elements: cadmium, cobalt, and chromium was determined. The results revealed that the genus Cunninghamella were able to grow in a relatively high concentration of radioactive elements and could be used in the absorption of radioactive elements from contaminated liquids.

The secondary metabolites of Penicillium janthinellum and P. duclauxii were affected by different concentrations of cadmium nitrate, sodium chloride, and sucrose. The fungal culture characteristics including mycelial fresh and dry weight, colony diameter, colony spore mass and reverse color, number of spores, and secondary metabolites were affected as well. Cyclopenin, carlosic acid, erythroskyrin, kojic acid, and patulin were produced by P. janthinellum on cadmium nitrate-free medium. However, cyclopenin, carlosic acid, frequentin, and islandicin were produced at 100ppm, and cyclopenin at 500ppm. On the other hand, the secondary metabolites produced by P. duclauxii were 9 on cadmium nitrate-free medium, 7 on medium containing 100 and 500ppm of cadmium nitrate, and 4 at 1000ppm cadmium nitrate concentration. Secondary metabolite brevianamide A was produced in the presence and absence of cadmium nitrate. The duclauxin, patulin, terrestic acid, and xanthomegin were produced only on cadmium nitrate-free medium. However, mycophenolic acid was produced only on cadmium nitrate-containing medium. The kojic acid was produced by P. janthinellum at 0.0%, 0.5%, 1.0%, 2.0%, 3.0%, and 5.0% concentrations of sodium chloride. The carlosic acid, erythroskyrin, and patulin were produced only at 0.0% and 1.0%. While carolic acid and islandicin were produced at 1%, 2%, and 3% and frequentin was produced only at 2% and 3%. On the other hand, 8 secondary metabolites were produced by P. duclauxii at 0.0%, 0.5%, 1.0%, and 2.0% concentration of sodium chloride and only 4 were produced at 3%. The secondary metabolites produced by P. janthinellum were 7 at 10% and 20%, 6 at 30%, and 2 only at 40% concentrations of sucrose. However, 8 secondary metabolites were produced by P. duclauxii at 10%, 20%, 30% and 3 at 40% concentrations of sucrose.

The secondary m etabolite and fatty acid profiles o f Aspergillus flavus, A. parasiticus, A. ochraceus in a ddition t o Penicillium expansum were det ermined. The olive oil was found to af fect secondary metabolite and fatty acid profiles when add ed to the growth medium. Many secondary metabolites were detected only in presence on olive oil. On the other hand, some fatty acids were not produced when the fungus grown on medium supplemented with olive oil. Griseofulvin, 6- Methylsalicylic acid, and rubratoxin B were produced by Penicillium expansum grown on olive oil-free medium and on medium supplemented with oli ve oi l in co ncentration of 2%, 4%, and 6%. However, Epoxysuccinic acid, (-) flavoskyrin, 2-pyruvoylamino benzamide, Roquefortine B, Roquefortine C, and Stipitatic acid were produced by P. expansum only in presence of olive o il. On t he o ther hand, the presence of olive o il in t he growth medium prevented the t errein and xanthomegnin pro duction. The fatty acids B utyric, ca proic, ca prylic, ca pric, un decylic, l auric, m yristic, p entadecylic, and palmitoleic were detected in P. expansum grown on oli ve oi l-free medium and not detected on medium supplemented with olive oil. Cyclopenol, desacetylpebrolide, (-) flavoskyrin, fumarprotocetraric acid, lobaric acid, p rotocetraric acid, an d rubratoxin B were produced by Aspergillus flavus, A. parasiticus only i n presence olive oil. Alectoronic acid, a ustdiol, cinnamic acid, a-c ollatolic acid, an d fulvic acid were produced only b y A. ochraceus grown on medium supplemented with olive oil. Caprylic, capric, undecylic, lauric, and myristic were detected in bo oth A. flavus and A. ochraceus grown on olive oil- free medium and not detected in A. parasiticus.

Three fungal strains; namely, Aspergillus terreus, Penicillium janthinellum and Penicillium duclauxii were cultured on different growth media including yeast extract, malt extract, yeast-malt extract, Czapek's Dox, Sabourod's, Harrlod's, and potato dextrose. The growth and secondary metabolites of the three fungal strains were greatly affected by the growth medium. The colour of the culture and secondary metabolites were noticeably altered and changed according to the growth medium used.