Monerah R. Al-Othman

Amhezole, A Novel Fungal Secondary Metabolite from Aspergillus terreus for Treatment of Microbial Mouth Infection

Bio‐guided fractionation of Aspergillus terreus extract leads to isolation of a novel terpenoidal secondary metabolite. The isolated compound and the total alcoholic extract of Aspergillus terreus showed a remarkable activity against microbial mouth infections; namely, Candida albicans, Lactobacillus acidophilus, Streptococcus gordonii, and S. mutan. Moreover, the Minimum Inhibitory Concentration of the isolated compound was determined and showed low values. The combination of each of the alcoholic extract of A. terreus and the isolated compound Coe‐Comfort tissue conditioner inhibited the growth of Candida albicans at concentrations of 500 and 7.81 µg/mL, respectively, Lactobacillus acidophilus at concentrations of 250 and 7.81 µg/mL, respectively, Streptococcus gordonii at concentrations of 1000 and 62.50 µg/mL, respectively, and S. mutans at concentrations of 1000 and 125 µg/mL, respectively. The oral dosing of the extract and the isolated compound did not show any significant effect on the activity of alanine aminotransferase, aspirate aminotransferase, and the levels of blood urea and serum creatinine. Copyright

Biological activity of fungal secondary metabolites

Abstract: Fungi are cosmopolitan organisms that inhabit almost all ecological niches of the earth and have the ability to utilise various substrates as a consequence of diversity of their biological and biochemical evolution. Fungi, during their development, follow different metabolic pathways that led to production of numerous intermediate and/or end-product compounds called as secondary metabolites. Fungi, filamentous forms, produce a diverse array of secondary metabolites that are small molecules, and not necessary for normal growth or development. Secondary metabolites have a tremendous impact on society; some are exploited for their antibiotic and pharmaceutical activities, others are involved in disease interactions with plants or animals. Most fungal secondary metabolites are synthesised from only a few key precursors in pathways that comprise a relatively small number of reactions and which branch off from primary metabolism at a limited number of points. However, the roles of secondary metabolites in the fungi that produce them are still more or less a mystery.

Comparative nutritional value and antimicrobial activities between three Euphorbia species growing in Saudi Arabia

Plants are excellent sources of nutrition and highly bioactive substances that might use in the development of new drugs and pharmaceutical agents. Three species of the Genus Euphorbia (Family Euphorpiaceae), namely; Euphorbia granulata Forssk, Euphorbia helioscobia L., and Euphorbia hirta Linn growing in Ryiadh, KSA were air-dried, powdered, and their active materials were extracted with alcohol. The nutritional value phytochemical constituents and antimicrobial activity of the plants were determined. The chemical contents were similar in the three species; however, lipid profile of the plants showed that the stearic acid and lignoceric acid were detected only in E. helioscopia and E. hirta, while palmitoleic acid was detected only in E. hirta. The percentage of unsaturated fatty acid methyl esters were 52.48%, 69.39% and 66.52% in Euphorbia granulate, Euphorbia helioscobia, E. hirta, respectively. Three compounds, 1-ethoxypentacosane, heptacosan-1-ol and β-sitosterol were isolated from the three plant extracts and identified using different spectroscopic analysis. The percentage of crude protein was 43.65%, 25.00% and 18.75% in E. granulata, E. helioscobia, and E. hirta, respectively. The free amino acids and amino acid composition were quantitatively determined using amino acid analyzer. All the plant extracts were active against bacterial and fungal test organisms, however, the antimicrobial activity were varied according to both the Euphorbia species and the test organism.

Developments in using fatty acids in fungal chemotaxonomy

The cellular fatty acid composition of nine species of Fusarium; namely, Fusarium anthophilum, F. avenaceum, F. cerealis, F. graminearum, F. graminum, F. oxysporum f. sp. conglutinans, F. pseudograminearum, F. roseum and F. sacchari var. elongatum growing on malt extract medium were determined. The fatty acid profiles of the investigated fungi showed very little variation and could only differentiate between few species. However, by adding certain chemical compounds including aspartic acid, glutamic acid, methionine, selenium and urea to the growth medium, the variation of the fatty acid profile was greatly increased and differentiated between all the investigated fungi. For example, pentadecanoic acid was not produced by F. anthophilum on malt extract broth (MEB) but only produced on MEB supplemented with aspartic acid. On the other hand, linolenic fatty acid was neither produced by F. anthophilum nor F. roseum grown on MEB, but it was produced by F. anthophilum in presence of aspartic acid and by F. roseum in the presence of glutamic acid. The fatty acid profiles could be useful for characterization and identification of fungi if determined under different conditions.

Anticandidal activity of the extract and compounds isolated from Cyperus conglomertus Rottb

The phytochemical screening of Cyperus conglomeratus showed that carbohydrates and/or glycosides, flavonoids, tannins, sterols and/or triterpenes, and proteins and/or amino acids are present. The fatty acid profile comprised major; palmitic, oleic, heptadecanoic, linoleic and minor; arachidonic, lignoceric, stearic, and myristic acid. Two compounds; namely, α-amyrin and β-sitosterol were isolated by the fractionation of unsaponifiable matter. The acute toxicity study showed that the reported after oral administration of the alcohol extract (TAE) showed that the plant was highly safe as the LD50 was more than 4000 mg/kg. These results were well supported by the sub-chronic toxicity, as the TAE administrated to rats for 15 consecutive days at dose 1000 mg/kg showed no alteration in the liver and kidney functions. Moreover, the extract of the plant exhibited anti-candidal activity against different Candida species. The most potent activity, (23.1 ± 2.1, 0.98 µg/ml) and (22.3 ± 0.53, 0.98 µg/ml), was obtained by the chloroform and total extract, respectively against Candida albicans.

Phytochemical standardization and biological activities of certain desert plants growing in Saudi Arabia

The phytochemical screening, antimicrobial and antitumor activities of Calendula tripterocarpa, Centarea sinaica, Centaurea pseudosinaica, Koelpinia linearis, Plectranthus arabicus, Plectranthus asirensis and Tripleurospermum auriculatum determined. The best antibacterial activity; 41.8 ± 0.23 mm, 39.7 ± 0.25 mm, 35.8 ± 0.58 mm, 34.7 ± 0.51 mm and 32.7 ± 0.25 mm was obtained by Plectranthus arabicus against Klebsiella pneumonia, Tripleurospermum auriculatum against Bacillus subtilis, Centaurea pseudosinaica against Bacillus subtilis, Centaurea pseudosinaica against Stroptococcus pyogenes and Plectranthus arabicus against Staphylococcus epidermidis, respectively. While the highest antifungal activity; 35.9 ± 1.15 mm, 34.6 ± 0.34, 30.6 ± 0.26 mm and 29.9 ± 0.63 mm was obtained by Tripleurospermum auriculatum against Geotricum candidum, Candida albicans, C. tropicalis and Aspergillus fumigatus, respectively. The antitumor activity (IC50) obtained by Centarea sinaica; 3.1 ± 6.9 µg/ml, 14.3 ± 3.1 µg/ml and 22.7 ± 4.1 µg/ml was better than activity of vinblastine sulphate; 5.9 ± 0.4 µg/ml, 59.7 ± 2.1 µg/ml and 30.3 ± 1.4 µg/ml against breast carcinoma (MCF-7), cervical carcinoma (Hela) and colorectal carcinoma (CACO), respectively. Plectranthus arabicus alcoholic extract showed higher antitumor activity; 15.3 ± 5.3 µg/ml, 28.6 ± 3.6 µg/ml and 24.3 ± 4.1 µg/ml than vinblastine; 21.2 ± 0.9 µg/ml, 59.7 ± 2.1 µg/ml and 30.3 ± 1.4 µg/ml against prostate carcinoma (Pc3), cervical carcinoma (Hela) and colorectal carcinoma (CACO), respectively. Also, the antitumor activity of Plectranthus asirensis against cervical carcinoma (Hela) (37.1 ± 2.6 µg/ml) was potent than vinblastine sulphate (59.7 ± 2.1 µg/ml). The obtained results of LD50 and sub-chronic toxicity revealed that the plants have no toxicity.

Cyanobacterial extra-metabolites against some pathogenic bacteria

Ten cyanobacterial species ( Nostoc calcicola , Nostoc commune, Nostoc entophytum, Nostoc minutum, Nostoc palndosum, Nostoc passerianum, Nostoc punctiforme, Anabaena ambigua, Anabaena amomala, and Anabaena doliolum ) were isolated from the mangrove region of Ras Mohammed (Sinai, Egypt), and were tested for their allelopathic activities including inhibitory and/or promoting effects against two Gram positive bacteria ( Bacillus subtilis and Staphylococcus aureus ) and two Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa ). Data suggested two types of allelopathic effects: one type which always appeared in cyanobacterial medium as in the case with N. minutum (medium that inhibits the growth of all tested bacterial species). The other type is induced only when cyanobacteria are in contact with bacteria; this is the case when the growth of both B. subtilis and S. aureus were inhibited in co-culture with N. commune. On the other hand, promotion effects of bacterial growth were observed when grown in cyanobacterial metabolites in most of studied cyanobacterial species. The biological assays for aqueous and methanolic extracts of the two Nostoc species revealed that both extracts for each species were not toxic at concentrations of 0.52 and 0.59 g L -1 water extract for N. commune and N. minutum , respectively and 0.31 and 0.425 g L -1 for methanolic extract for N. commune and N. minutum , respectively. No mortality was observed in tested mice within 72 h.

Anticandidal Activity of Extracts and a Novel Compound, Amnomopin, Isolated From Petriella setifera

A novel triterpenoidal compound named ‘amnomopin’ (3β‐diglucoside‐5,12‐28‐oic acid), which is named IUPAC as 3‐O‐(2′ ➔ 1″diglucoside)1,2,3,4,4a,5,6,6a,6b,7,9,10,11,12,12a,12b,13,14b‐octadecahydro‐10‐hydroxy‐2,2,6a,6b,9,9,12a‐heptamethylpicene‐4a‐carboxylic acid, was isolated from the extract Petriella setifera. The total alcoholic extract of P. setifera showed a great activity against clinically isolated Candida species, including Candida albicans, Candida dubliniensis, Candida famata, Candida glabrata, Candida inconspicua, Candida kefyr, Candida krusei, Candida norvegensis, Candida parapsilosis and Candida tropicalis. Also, the new compound amnomopin was active against all the investigated Candida species. The highest anticandidal activity of P. setifera extract was obtained against C. kefyr (22.6 ± 1.5 mm), C. albicans and C. norvegensis (21.3 ± 0.63 mm) and C. krusei (20.6 ± 1.5 mm). Moreover, the minimum inhibitory concentrations of both the total extract and the isolated compound were low. The minimum inhibitory concentration of the compound isolated from P. setifera was 0.49 μg/mL against C. kefyr, 0.98 μg/mL against C. albicans and C. norvegensis and 1.95 μg/mL against C. krusei. The oral dosing of the extract and the isolated compound did not show any significant effect on the activity of alanine aminotransferase, aspirate aminotransferase and the levels of blood urea and serum creatinine. Copyright

Isolation, identification and anti-candidal activity of filamentous fungi from Saudi Arabia soil

Ten fungal strains; namely, Penicillium melinii, Petriella setifera, Aspergillus pseudo-niger, Alternaria chlamydospora, Pythium nayoroense, Phoma glomerata, Mucor ramosissimus, Mucor racemosus, Fusarium chlamydosporum and Rhizopus azygosporus were isolated from soil. The extra- and intra-cellular extracts of the fungal strains grown on malt extract and yeast-extract sucrose media were screened for their anticandidal activity against different clinically-isolated Candida species. Most of the fungal extracts showed activity against different Candida species. However, the fungal strains grew on malt extract showed greater activities than those grew on yeast extract sucrose media. The activity of the intracellular was higher than the extracellular metabolites. All fungal extracts (extra and intra) were similar in chemical constituent; they contained carbohydrates and/or glycosides, unsaturated sterols and/or triterpens, tannins and traces of coumarins. Alkaloids, flavonoids, saponins, anthraquinones and cardenolides were no detected. The intra-cellular extracts contained more compounds than the extra-cellular extracts.

Quantitative and qualitative analysis for standardization of Euphorbia cuneata Vahl

Euphorbia cuneata Vahl very promising plant belongs to Family Euphorbiaceae The present study was carried out on the Euphorbia cuneata Vahl to standardize its components. Qualitative and quantitative phytochemical analysis showed variable phytochemical groups. Examination of Successive Extraction showed that there are different color, constancy, phytochemical groups and yield in each extract, the highest percentage was found in ethanol (10.7 ± 1.01) and the lowest one in ether (1.66 ± 0.31). Analysis of primary and secondary metabolites of Euphorbia cuneata Vahl revealed that the primary metabolites percent (carbohydrate, lipid and protein 6.25 ± 1.11, 5.12 ± 1.40, 7.15 ± 1.31 W/w respectively) were lower than secondary metabolites (flavonoids, phenolic and tannins 11.26 ± 1.02, 9.15 ± 1.21and 5.23 ± 1.29 W/w respectively). The Pharmacopoeia Constants were determined. Amino acids analysis of the arial parts reported the presence of 15 amino acids with different percentage in different types. (Total, free and protein hydrolysate.) Arginine represented the highest concentration (20.86).