Mohammad Magdy El-Metwally

1. Alkaloids comprise a broad category of naturally occurring substances served for developing of new drugs (Casciaro et al. 2020). Indole alkaloids hyphenated with various chromophores are of sign...

The nutritional composition, antioxidant, and biological properties of Terfezia boudieri Chatin, a desert truffle largely distributed in Egypt were evaluated. Carbohydrates were the most abundant macronutrients (15.4 g/100 g) followed by proteins (9.04 g/100 g), and ash and fat contents were 4.47 and 3.82 g/100 g, respectively. Arabinose was recorded in a high amount (3.02 g/100 g) while fructose was found in a small amount (0.2 g/100g). Citric acid is considered the main organic acid (5.03 g/100 g) while p-Hydroxybenzoic acid is considered the main phenolic acid (10.65 g/100 g) in T. boudieri (dry mass). Also, higher content of the essential linoleic, oleic, and palmitic acids (44.9%, 19.05%, and 11.38% respectively) were determined. Furthermore, the truffle extracts were tested for their antioxidant, antibacterial, and antifungal activities. Aqueous extract showed the highest antioxidant activity (IC50 value =221.9 µg) more than organic solvent extracts. Also, all Gram-positive and unicellular fungi (yeasts) exhibited the highest sensitivity to aqueous extract of T. boudieri while organic solvent extracts had great ability to inhibit the growth of Gram-negative and filamentous fungi.

Bacteria have their own language through which they communicate with one another like all higher organisms. So, many researchers are working hard to identify and comprehend the components of this bacterial communication, known as quorum sensing (QS). In quorum sensing, bacteria use signaling molecules called autoinducers (AIs) to exchange information. Many natural compounds and extraction techniques have been intensively studied to disrupt bacterial signaling and examine their effectiveness for bacterial pathogenesis control. Quorum sensing inhibitors can interfere with QS and block the action of AI signaling molecules. Recent research indicates that quorum sensing inhibitors (QSIs) and quorum quenching enzymes (QQEs) show great promise in reducing the pathogenicity of bacteria and inhibiting biofilm synthesis. In addition, the effectiveness of QQEs and QSIs in experimental animal models was demonstrated. These are taken into account in the development of innovative medical devices, such as dressings and catheters, to prevent bacterial infections. The present review highlights this aspect with a prospective vision for its development and application.

One of hidden mine of antibiotics is endophytic fungi especially that inhibited medicinal plants. In this regard, leaves, stems, fruits and bulbs of some commonly medicinal plants growing in Northwestern coast of Egypt were subjected for isolation of endophytic fungi with screening study of its antimicrobial activity. Practically, more than one hundred (101) endophytic fungal species isolated from Scorpiurus muricatus, Mellilotus indicus, Lotus polyphyllos, Ononis vaginalis, Nicotiana glauca, Lycium europaeum, Asphodelus aestivus, Echium angustifolium,Fagonia cretica, Pancratium maritimum,and Carduus getulus were tested in vitro for their antimicrobial activities against E. coli, Pseudomonas argenosa, Staphylococcus aureus, Bacillus subtilus, Candida albicanus, Candida glabrata, Penicillium expansum, Aspergillus flavus. The values of applied diversity indices revealed significant differences in presence, absence and abundance among endophytic fungal isolates. To the best of our knowledge, the present study is the first to report of Alternaria pluriseptata as endophytic species with most dominant and most active in its anitimicrobial activity among the isolated species. Seven distinctive groups were revealed from the two-way cluster analysis showing the intensity of antimicrobial activity against tested pathogens: Twenty-five percent of the isolates (26 strains assembled together in group V) exhibited no antimicrobial activity against all tested pathogens while six percent (6 isolates) assembled in group VII revealed high antimicrobial activity against five pathogens.

The anticancer activity of terretonin N (1) and butyrolactone I (2), obtained from the thermophilic fungus Aspergillus terreus TM8, was intensively studied against prostate adenocarcinoma (PC-3) and ovary adenocarcinoma (SKOV3) human cell lines. According to this study, both compounds showed potent cytotoxicity towards ovarian adenocarcinoma cells (SKOV3) with IC₅₀ 1.2 and 0.6 μg/mL, respectively. With respect to metastatic prostate cells (PC-3), the two compounds 1 and 2 showed a significantly promising cytotoxicity effect with IC₅₀ of 7.4 and 4.5 μg/mL, respectively. The tested fungal metabolites showed higher rates of early and late apoptosis with little or no necrotic apoptotic pathway in all treated prostate adenocarcinoma (PC-3) and ovary adenocarcinoma (SKOV3) human cell lines, respectively. The results reported in this study confirmed the promising biological properties of terretonin N (1) and butyrolactone I (2) as anticancer agents via the induction of cellular apoptosis. However, further studies are needed to elucidate the molecular mechanism by which cellular apoptosis is induced in cancer cells.

A. fumigatus KJ432867, a newly isolated strain of the thermotolerant fungus used in the current study was isolated from agriculture soil, Beheira governorate, Egypt. The identification of the fungus based on morphology and sequence analysis of ITS1-5.8S rDNA-ITS2. Five crop wastes namely wheat bran, wheat straw, rice hulls, rice straw and broken rice grain were used to induce the thermostable amylase production by A. fumigatus KJ432867 via semisolid state fermentation. The data revealed that wheat bran is the most suitable for the fungus for glucoamylase production which further improved using Plackett-Burman and Box-Behnken designs. Optimum conditions for the production of thermostable amylase are found to be pH 6, wheat bran 1 gm, yeast extract 6 mg/gm, berij35 40 µL/gm, (NH4)2SO4 24 mg/gm and an inoculum of 6 x 105 spore/ml with thermostable glucoamylase production titer of 161.11 U/gm after 6 days. FeCl3, BaCl2, and CaCl2 positively affect glucoamylase activity with highest main effect value of FeCl3 ions where MgCl2 has the highest negative main effect on activity. The kinetic constants Km is 1.37 mg/ml with three bands in zymogram. Moreover the enzyme showed good cleaning effect when applied in starch patches in textile. Glucoamylase of A. fumigatus KJ432867 exhibited good thermostability as it loss only 28.95% from its original activity after treatment with heat at 80°C for 3 hours. Finally, the thermostable glucoamylase from A. fumigatus KJ432867 can be produced from cheap agrowaste via simple fermentation technique with good biochemical features for many biotechnological applications.

Aflatoxins are part of fungal secondary metabolites which become serious health, environmental, and economic problems and can cause corruption of many crops and agricultural grains that used as food and feed for human and animal. Aflatoxins mainly produce by Aspergillus spp. especially Aspergillus flavus and Aspergillus parasiticus. The present work aimed to study the effect of nanoencapsulation of chitosan (CS) nanoparticles with two phenolic compounds 1‐(2‐ethyl,6‐heptyl)phenol (EHP) extracted from Cuminum cyminum and 5‐ethyl‐2‐(methoxymethyl)phenol (EMMP) extracted from black pepper on growth and aflatoxins production of A. flavus and A. parasiticus. A. flavus growth was completely inhibited by 0.6 mg/ml of EHP and EMMP as well as A. parasiticus which showed the same minimal inhibition concentration with the first compound and 0.8 mg/ml with the second one. CS nanoparticles inhibited the growth of the tested organisms more than CS especially with A. parasiticus and this potency became much better when nanoencapsulated with the two extracted phenolic compounds. In inhibition of aflatoxins production, EHP reduced the production of aflatoxin B1 and B2 of A. flavus by 68.6% and 69.7%, respectively. In the same manner EMMP reduce the production of the two toxins by 87.3% and 82.6%, respectively. The reduction effect of CS nanoparticles is much more than that of CS as it record in most cases about twofold increase. Nanoencapsulation of CS nanoparticles by the extracted phenolic compounds is much more effective with complete inhibition of aflatoxin B1 of both fungi and aflatoxin G1 of A. parasiticus.

Investigation of bioactive secondary metabolites from terrestrial Aspergillus oryzae sp. MMAO1 using M₂ medium afforded a new diketopiperazine alkaloid, 7,9-dihydroxy-3-(1H-indol-3-ylmethyl)-8-methoxy-2,3,11,11a-tetrahydro-6H-pyrazino[1,2-b]isoquinoline-1,4-dione (1a), containing the unusual amino acid l-6,8-dihydroxy-7-methoxyphenylalanine. This was co-isolated with ditryptophenaline (2), cyclo-(Tryp,Tyr) (4), cyclo-(Pro,Val), α-cyclopiazonic acid (3), kojic acid and uridine. Re-cultivation of the fungal strain on Dox medium led to the production of bisdethio(bismethylthio)gliotoxin (5), pseurotin A (6) along with linoleic acid, α-cyclopiazonic acid (3) and kojic acid. The chemical structure of the new diketopiperazine alkaloid including the relative configuration was determined by 1D and 2D NMR spectroscopy and HR-ESI-MS spectrometry, and by comparison with the related literature. The new alkaloid (1a) showed no antimicrobial activity or cytotoxicity against brine shrimps.