Ghezzi, D., L. Salvi, P. E. Costantini, A. Firrincieli, M. Iorio, E. Lopo, M. Sosio, A. H. Elbanna, Z. G. Khalil, R. J. Capon, et al., Ancient and remote quartzite caves as a novel source of culturable microbes with biotechnological potential, , vol. 286, pp. 127793, 2024. AbstractWebsite

Quartzite caves located on table-top mountains (tepuis) in the Guyana Shield, are ancient, remote, and pristine subterranean environments where microbes have evolved peculiar metabolic strategies to thrive in silica-rich, slightly acidic and oligotrophic conditions. In this study, we explored the culturable fraction of the microbiota inhabiting the (ortho)quartzite cave systems in Venezuelan tepui (remote table-top mountains) and we investigated their metabolic and enzymatic activities in relation with silica solubilization and extracellular hydrolytic activities as well as the capacity to produce antimicrobial compounds. Eighty microbial strains were isolated with a range of different enzymatic capabilities. More than half of the isolated strains performed at least three enzymatic activities and four bacterial strains displayed antimicrobial activities. The antimicrobial producers Paraburkholderia bryophila CMB_CA002 and Sphingomonas sp. MEM_CA187, were further analyzed by conducting chemotaxonomy, phylogenomics, and phenomics. While the isolate MEM_CA187 represents a novel species of the genus Sphingomonas, for which the name Sphingomonas imawarii sp. nov. is proposed, P. bryophila CMB_CA002 is affiliated with a few strains of the same species that are antimicrobial producers. Chemical analyses demonstrated that CMB_CA002 produces ditropolonyl sulfide that has a broad range of activity and a possibly novel siderophore. Although the antimicrobial compounds produced by MEM_CA187 could not be identified through HPLC-MS analysis due to the absence of reference compounds, it represents the first soil-associated Sphingomonas strain with the capacity to produce antimicrobials. This work provides first insights into the metabolic potential present in quartzite cave systems pointing out that these environments are a novel and still understudied source of microbial strains with biotechnological potential.

Elbanna, A. H., S. Abdelghany, S. Alseekh, A. R. Fernie, and M. A. Farag, Seasonal and taxa impact on edible sea cucumber metabolome as analyzed via a multiplex approach of mass spectroscopy-based metabolomics, , vol. 57, pp. 103456, 2024. AbstractWebsite

Sea cucumbers, belonging to class Holothuroidea, are marine invertebrates with substantial bioactive compounds and nutritive value. This study presents a multiplex metabolomics approach to dissect between winter and summer samples of two Red Sea cucumbers: Holothuria atra and Actinopyga crassa. LC-MS and GC-MS followed by multivariate data analyses were employed for metabolites profiling and seasonal biomarkers assignment for each species. A total of 314 metabolites were annotated in both species belonging to amino acids, sugars, sugar alcohols, acids, triacylglycerides (TAGs), phospholipids, lyso-phospholipids, sphingolipids, phosphatidylcholines, diacylglycerols, different glycolipids, and others, adding to the nutritive value of sea cucumber. GC-MS analysis revealed for amino acids i.e., alanine as the main polar primary metabolite class in sea cucumbers. LC-MS analysis targeting non-polar metabolites revealed TAGs as the main class followed by phospholipids and lyso-phospholipids. Multivariate orthogonal partial least square discriminant analysis (OPLS-DA) revealed that A. crassa is enriched in alanine and lactic acid than H. atra versus higher levels of pyroglutamic acid and ethanolamine and TAGs in the later. Summer A. crassa was distinguished from its winter specimen by its higher TAGs, glycine and glycerol levels versus enrichment of winter samples in lyso-phospholipids, isoleucine, and proline. Such metabolomic study revealed for A. crassa and H. atra richness in nutrient metabolites, alongside collection season effect on their amino acids and lipids profiles.

Dewa, A. A., Z. G. Khalil, A. H. Elbanna, and R. J. Capon, "Chrysosporazines Revisited: Regioisomeric Phenylpropanoid Piperazine P-Glycoprotein Inhibitors from Australian Marine Fish-Derived Fungi", Molecules, vol. 27, issue 10, 2022. Abstract

A library of fungi previously recovered from the gastrointestinal tract (GIT) of several fresh, commercially sourced Australian mullet fish was re-profiled for production of a rare class of phenylpropanoid piperazine alkaloids (chrysosporazines) using an integrated platform of; (i) miniaturized 24-well plate cultivation profiling (MATRIX), (ii) UPLC-DAD and UPLC-QTOF-MS/MS (GNPS) chemical profiling, and; (iii) precursor directed biosynthesis to manipulate in situ biosynthetic performance and outputs; to detect two new fungal producers of chrysosporazines. Chemical analysis of an optimized PDA solid phase cultivation of Aspergillus sp. CMB-F661 yielded the new regioisomeric chrysosporazine T (1) and U (2), while precursor directed cultivation amplified production and yielded the very minor new natural products azachrysosporazine T1 (3) and U1 (4), and the new unnatural analogues neochrysosporazine R (5) and S (6). Likewise, chemical analysis of an optimized M1 solid phase cultivation of Spiromastix sp. CMB-F455 lead to the GNPS detection of multiple chrysosporazines and brasiliamides, and the isolation and structure elucidation of chrysosporazine D (7) and brasiliamide A (8). Access to new chrysosporazine regioisomers facilitated structure activity relationship investigations to better define the chrysosporazine P-glycoprotein (P-gp) inhibitory pharmacophore, which is exceptionally potent at reversing doxorubrin resistance in P-gp over expressing colon carcinoma cells (SW600 Ad300).

Dewa, A. A., A. H. Elbanna, Z. G. Khalil, and R. J. Capon, "Neochrysosporazines: Precursor-Directed Biosynthesis Defines a Marine-Derived Fungal Natural Product P-Glycoprotein Inhibitory Pharmacophore", Journal of Medicinal ChemistryJournal of Medicinal Chemistry, vol. 65, issue 3: American Chemical Society, pp. 2610 - 2622, 2022. AbstractWebsite
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Elbanna, A. H., E. A. Mahrous, A. E. Khaleel, and T. S. El-Alfy, In-vitro anti-hyperglycemic and anti-oxidant activities of Bauhinia vahlii Wight & Arnott. growing in Egypt, , 2015.
Farag, M. A., A. E. M. Sayed, A. el Banna, and S. Ruehmann, "Metabolomics reveals distinct methylation reaction in MeJA elicited Nigella sativa callus via UPLC–MS and chemometrics", Plant Cell, Tissue and Organ Culture (PCTOC), vol. 122, issue 2, pp. 453-463, 2015. Abstract

Cell suspension cultures are now recognized as important model for studying natural products biosynthesis and functional genomics. Nevertheless, very few studies of metabolic comparisons between cell cultures (callus) and original plants have been reported, even though the biological identity of cultured cells with the normally grown plant is of great importance. In this study, an MS-based metabolomic approach was used to compare the natural products profile of intact Nigella sativa seeds versus callus . N. sativa has been used for centuries in traditional medicine for several purposes. Its phytochemical components comprise, among others, alkaloids, saponins, flavonoids and fatty acids. Ultra performance liquid chromatography coupled to ultraviolet photodiode array detection and high resolution q-TOF mass spectrometry (UPLC–PDA–MS) was utilized to analyze the secondary product metabolome of N. sativa callus, with a total of 74 metabolites including five flavonoids, 13 hydroxycinnamates, an alkaloid, saponin and 14 fatty acids. Callus maintained the capacity to produce N. sativa phenolic subclasses, with hydroxycinnamates amounting for the major secondary metabolites in callus. Alkaloids, major constituents in Nigella genus, were detected in callus though with qualitative and quantitative differences from seed tissue. Methyl jasmonate (MeJA) elicitation effect was assessed on callus with the aim of increasing secondary metabolites production. Metabolite profiles were subjected to principal component analysis and orthogonal projection to latent structures-discriminant analysis to evaluate MeJA effect. Results revealed that MeJA led to O-methylation reaction induction yielding O-feruloylquinic acid from O-caffeoylquinic acid, in addition to a methylated disaccharide. The work extends our knowledge regarding hydroxycinnamates biosynthesis, regulation and on metabolic engineering future efforts to increase its production as potential phytoalexin in N. sativa.

Elbanna, A. H., M. M. Nooh, E. A. Mahrous, A. E. Khaleel, and T. S. El Alfy, "Extract of Bauhinia vahlii Shows Antihyperglycemic Activity, Reverses Oxidative Stress, and Protects against Liver Damage in Streptozotocin-induced Diabetic Rats", Pharmacognosy Magazine, vol. 13, issue Suppl 3, pp. S607-S612, 2017. Abstract

Several studies have affirmed the effectiveness of some Bauhinia plants as antihyperglycemic agents. We investigated the possible effect of Bauhinia vahlii leaves extract in reducing hyperglycemia and reversing signs of organ damage associated with diabetes in streptozotocin (STZ) rat model. Both polar fraction of the B. vahlii leaves (defatted ethanolic extract [DEE]) and nonpolar fraction (n-hexane extract) were evaluated in vitro for α-glucosidase inhibition and 2,2-diphenyl-1-picrylhydrazyl radical scavenging potential. DEE was selected for further in vivo studies and was administered at two doses, i.e., 150 or 300 mg/kg to STZ-diabetic rats for 4 weeks. Only DEE exhibited in vitro antioxidant and antihyperglycemic activities and its oral administration at both dose levels resulted in significant reduction in fasting blood glucose and glycated hemoglobin. Furthermore, signs of oxidative stress as indicated by hepatic reduced glutathione, nitric oxide, and malondialdehyde levels were completely reversed. In addition, histopathological examination and measurement of serum aspartate transaminase and alanine transaminase levels showed that DEE protected the liver from signs of liver pathogenesis when compared to diabetic untreated animals and those treated with metformin. Phytochemical analysis of DEE showed high flavonoids content with quercitrin as the major constituent along with other quercetin glycosides. This study strongly highlights the possible beneficial effect of B. vahlii leaves extract in relieving hyperglycemia and liver damage in STZ-diabetic rats and recommends further investigation of the value of quercetin derivatives in controlling diabetes and ameliorating liver damage associated with it. The polar fraction of the Bauhinia vahlii leaves (defatted ethanolic extract [DEE]) exhibited both in vitro antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl scavenging assay and strong α-glucosidase inhibition while the nonpolar fraction (n-hexane extract) failed to show any activity in both assays. DEE was further investigated in streptozotocin-induced diabetic rat model where oral administration of DEE at 2 doses (150 and 300 mg/kg) for 4 weeks resulted in significant reduction in fasting blood glucose and glycated hemoglobin and reversal of oxidative stress signs as indicated by measurement of hepatic reduced glutathione, nitric oxide, and malondialdehyde levels. In addition, histopathological examination and measurement of serum aspartate transaminase and alanine transaminase levels showed that DEE protected the liver from signs of pathogenesis observed in diabetic untreated rats. Phytochemical analysis of DEE showed high flavonoid content with quercitrin as the major constituent (62.9 ± 0.18 mg/mg). The polar fraction of the Bauhinia vahlii leaves (defatted ethanolic extract [DEE]) exhibited both in vitro antioxidant activity in 2,2-diphenyl-1-picrylhydrazyl scavenging assay and strong α-glucosidase inhibition while the nonpolar fraction (n-hexane extract) failed to show any activity in both assays. DEE was further investigated in streptozotocin-induced diabetic rat model where oral administration of DEE at 2 doses (150 and 300 mg/kg) for 4 weeks resulted in significant reduction in fasting blood glucose and glycated hemoglobin and reversal of oxidative stress signs as indicated by measurement of hepatic reduced glutathione, nitric oxide, and malondialdehyde levels. In addition, histopathological examination and measurement of serum aspartate transaminase and alanine transaminase levels showed that DEE protected the liver from signs of pathogenesis observed in diabetic untreated rats. Phytochemical analysis of DEE showed high flavonoid content with quercitrin as the major constituent (62.9 ± 0.18 mg/mg). Abbreviations used: ALT: Alanine transaminase, AST: Aspartate transaminase, DEE: Defatted ethanol extract, DPPH: 2,2-diphenyl-1-picrylhydrazyl, FBG: Fasting blood glucose, GAE: Gallic acid equivalent, GSH: Reduced glutathione, Hb1Ac: Glycated hemoglobin, HE: Hexane extract MDA: Malondialdehyde, QE: Quercetin equivalent, STZ: Streptozotocin, TAC: Total antioxidant capacity.

Dewa, A. A., Z. G. Khalil, A. H. Elbanna, and R. J. Capon, "Chrysosporazines Revisited: Regioisomeric Phenylpropanoid Piperazine P-Glycoprotein Inhibitors from Australian Marine Fish-Derived Fungi", Molecules, vol. 27, issue 10, pp. 3172, 2022. Abstract

A library of fungi previously recovered from the gastrointestinal tract (GIT) of several fresh, commercially sourced Australian mullet fish was re-profiled for production of a rare class of phenylpropanoid piperazine alkaloids (chrysosporazines) using an integrated platform of; (i) miniaturized 24-well plate cultivation profiling (MATRIX), (ii) UPLC-DAD and UPLC-QTOF-MS/MS (GNPS) chemical profiling, and; (iii) precursor directed biosynthesis to manipulate in situ biosynthetic performance and outputs; to detect two new fungal producers of chrysosporazines. Chemical analysis of an optimized PDA solid phase cultivation of Aspergillus sp. CMB-F661 yielded the new regioisomeric chrysosporazine T (1) and U (2), while precursor directed cultivation amplified production and yielded the very minor new natural products azachrysosporazine T1 (3) and U1 (4), and the new unnatural analogues neochrysosporazine R (5) and S (6). Likewise, chemical analysis of an optimized M1 solid phase cultivation of Spiromastix sp. CMB-F455 lead to the GNPS detection of multiple chrysosporazines and brasiliamides, and the isolation and structure elucidation of chrysosporazine D (7) and brasiliamide A (8). Access to new chrysosporazine regioisomers facilitated structure activity relationship investigations to better define the chrysosporazine P-glycoprotein (P-gp) inhibitory pharmacophore, which is exceptionally potent at reversing doxorubrin resistance in P-gp over expressing colon carcinoma cells (SW600 Ad300).

Dewa, A. A., A. H. Elbanna, Z. G. Khalil, and R. J. Capon, "Neochrysosporazines: Precursor-Directed Biosynthesis Defines a Marine-Derived Fungal Natural Product P‑Glycoprotein Inhibitory Pharmacophore", Journal of Medicinal Chemistry, vol. 65, issue 3, pp. 2610-2622, 2022. Abstract

Upregulation of ATP binding cassette (ABC) transporter efflux pumps (i.e. P-glycoprotein, P-gp) can impart multidrug resistance, rendering many chemotherapeutics ineffective and seriously limiting treatment regimes. While ABC transporters remain an attractive target for therapeutic intervention, the development of clinically useful small-molecule inhibitors has proved challenging. In this report, we describe the structure–activity relationship (SAR) analysis of a newly discovered P-gp inhibitory pharmacophore, phenylpropanoid piperazine chrysosporazines, produced by co-isolated marine-derived fungi. In the absence of any total syntheses, we apply an innovative precursor-directed biosynthesis strategy that successfully repurposed fungal biosynthetic output, allowing us to isolate, characterize, and identify the structurally diverse neochrysosporazines A–Q. SAR analysis utilizing all known (and new) neochrysosporazines, chrysosporazines, and azachrysosporazines, plus semi-synthetic analogues, established the key structure requirements for the P-gp inhibitory pharmacophore, and, in addition, identified non-essential sites that allow for the design of affinity and other conjugated probes.

Salim, A. A., Z. G. Khalil, A. H. Elbanna, T. Wu, and R. J. Capon, "Methods in Microbial Biodiscovery", Marine Drugs, vol. 19, issue 9, pp. 503, 2021. Abstract

This review presents an account of the microbial biodiscovery methodology developed and applied in our laboratory at The University of Queensland, Institute for Molecular Bioscience, with examples drawn from our experiences studying natural products produced by Australian marine-derived (and terrestrial) fungi and bacteria.