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Li W, Chen Z, Li X, Li X, Hui Y, Chen W. The Biosynthesis, Structure Diversity and Bioactivity of Sterigmatocystins and Aflatoxins: A Review. J Fungi (Basel) 2024; 10:396. [PMID: 38921382 PMCID: PMC11204465 DOI: 10.3390/jof10060396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 05/21/2024] [Accepted: 05/29/2024] [Indexed: 06/27/2024] Open
Abstract
Sterigmatocystins and aflatoxins are a group of mycotoxins mainly isolated from fungi of the genera Aspergillus. Since the discovery of sterigmatocystins in 1954 and aflatoxins in 1961, many scholars have conducted a series of studies on their structural identification, synthesis and biological activities. Studies have shown that sterigmatocystins and aflatoxins have a wide range of biological activities such as antitumour, antibacterial, anti-inflammatory, antiplasmodial, etc. The sterigmatocystins and aflatoxins had been shown to be hepatotoxic and nephrotoxic in animals. This review attempts to give a comprehensive summary of progress on the chemical structural features, synthesis, and bioactivity of sterigmatocystins and aflatoxins reported from 1954 to April 2024. A total of 72 sterigmatocystins and 20 aflatoxins are presented in this review. This paper reviews the chemical diversity and potential activity and toxicity of sterigmatocystins and aflatoxins, enhances the understanding of sterigmatocystins and aflatoxins that adversely affect humans and animals, and provides ideas for their prevention, research and development.
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Affiliation(s)
- Wenxing Li
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China; (W.L.); (Z.C.); (X.L.); (X.L.)
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China
| | - Zhaoxia Chen
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China; (W.L.); (Z.C.); (X.L.); (X.L.)
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China
| | - Xize Li
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China; (W.L.); (Z.C.); (X.L.); (X.L.)
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China
| | - Xinrui Li
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China; (W.L.); (Z.C.); (X.L.); (X.L.)
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China
| | - Yang Hui
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China; (W.L.); (Z.C.); (X.L.); (X.L.)
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China
| | - Wenhao Chen
- Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China; (W.L.); (Z.C.); (X.L.); (X.L.)
- Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China
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Sana T, Khan M, Jabeen A, Shams S, Hadda TB, Begum S, Siddiqui BS. Urease and Carbonic Anhydrase Inhibitory Effect of Xanthones from Aspergillus nidulans, an Endophytic Fungus of Nyctanthes arbor-tristis. PLANTA MEDICA 2023; 89:377-384. [PMID: 36626924 DOI: 10.1055/a-1908-0935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Urease plays a major role in the pathogenesis of peptic and gastric ulcer and also causes acute pyelonephritis and development of infection-induced reactive arthritis. Carbonic anhydrases (CA) cause pathological disorders such as epilepsy (CA I), glaucoma, gastritis, renal, pancreatic carcinomas, and malignant brain tumors (CA II). Although various synthetic urease and carbonic anhydrase inhibitors are known, these have many side effects. Hence, present studies were undertaken on ethyl acetate extract of Aspergillus nidulans, an endophytic fungus separated from the leaves of Nyctanthes arbor-tristis Linn. and led to the isolation of five furanoxanthones, sterigmatin (1: ), sterigmatocystin (3: ), dihydrosterigmatocystin (4: ), oxisterigmatocystin C (5: ), acyl-hemiacetal sterigmatocystin (6: ), and a pyranoxanthone (2: ). Acetylation of 3: gave compound O-acetyl sterigmatocystin (7: ). Their chemical structures were elucidated by 1H and 13C NMR and MS. The inhibitory effect of isolated compounds was evaluated on urease and carbonic anhydrase (bCA II) enzymes in vitro. Compounds 3: and 6: showed significant urease inhibition (IC50 19 and 21 µM), while other compounds exhibited varying degrees of urease inhibition (IC50 33 - 51 µM). Compounds 4, 6: and 7: exhibited significant inhibition of bCA II (IC50 values 21, 25 and 18 µM respectively), compounds 1: -3: displayed moderate inhibition (IC50 61, 76 and 31 µM respectively) while 5: showed no inhibition. A mechanistic study of the most active urease inhibitors was also performed using enzyme kinetics and molecular docking. All compounds were found non-toxic on the NIH-3T3 cell line.
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Affiliation(s)
- Talea Sana
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Majid Khan
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Almas Jabeen
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Sidrah Shams
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Taibi Ben Hadda
- Laboratoire de Chimie des Matériaux, Faculté des Sciences, Université Mohammed Premier, Oujda, Morocco
| | - Sabira Begum
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Bina Shaheen Siddiqui
- H. E. J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
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Gengan RM, Chuturgoon AA, Dutton MF. Kinetics of the oxidoreductase involved in the conversion of O-methylsterigmatocystin to aflatoxin B1. Prep Biochem Biotechnol 2006; 36:297-306. [PMID: 16971301 DOI: 10.1080/10826060600912435] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Among the enzymatic steps in the aflatoxin biosynthetic pathway, the conversion of O-methylsterigmatocystin (OMST) to the potent environmental carcinogen aflatoxin B1 (AFB1), has been proposed to be catalysed by an oxidoreductase (OR) that requires a cytochrome P-450 type of oxidoreductase activity. This enzyme displays relative specificity towards OMST homologues in fungal whole cells. These studies were extended to the action of a cell-free enzyme system (CFES), on five OMST homologues, with a view to establish the kinetics. In the current study a CFES, containing an oxidoreductase, was derived from a blocked mutant of Aspergillus parasiticus (Wh1-11-105). The key experimental steps involved rapid concentration and efficient dialysis by membrane filtration to remove small biomolecules (MW<10,000), co-factors, primary and secondary metabolites. The kinetic parameters of the enzyme-substrate reactions indicated that the reaction follows a Michealis-Menten kinetics and OR activity decreased in the order: O-butylsterigmatocystin>O-propylsterigmatocystin>O-ethylsterigmatocystin>O-methylsterigmatocystin>O-acetylsterigmatocystin>O-benzoylsterigmatocystin. The 7-O-alkyl homologues were the best substrate for the CFES, thereby substantially supporting that the 7-O-methyl group of OMST is preferred for OR catalytic activity in the absence of any other alkylating groups in vitro. The Km was calculated as 5.65 microM for this CFES and varied marginally among the OMST homologues studied.
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Affiliation(s)
- Robert M Gengan
- Department of Chemistry, Faculty of Engineering, Science and the Built Environment, Durban University of Technology, Durban, South Africa.
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Lee LW, Chiou CH, Linz JE. Function of native OmtA in vivo and expression and distribution of this protein in colonies of Aspergillus parasiticus. Appl Environ Microbiol 2002; 68:5718-27. [PMID: 12406770 PMCID: PMC129877 DOI: 10.1128/aem.68.11.5718-5727.2002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The activities of two enzymes, a 168-kDa protein and a 40-kDa protein, OmtA, purified from the filamentous fungus Aspergillus parasiticus were reported to convert the aflatoxin pathway intermediate sterigmatocystin to O-methylsterigmatocystin in vitro. Our initial goal was to determine if OmtA is necessary and sufficient to catalyze this reaction in vivo and if this reaction is necessary for aflatoxin synthesis. We generated A. parasiticus omtA-null mutant LW1432 and a maltose binding protein-OmtA fusion protein expressed in Escherichia coli. Enzyme activity analysis of OmtA fusion protein in vitro confirmed the reported catalytic function of OmtA. Feeding studies conducted with LW1432 demonstrated a critical role for OmtA, and the reaction catalyzed by this enzyme in aflatoxin synthesis in vivo. Because of a close regulatory link between aflatoxin synthesis and asexual sporulation (conidiation), we hypothesized a spatial and temporal association between OmtA expression and conidiospore development. We developed a novel time-dependent colony fractionation protocol to analyze the accumulation and distribution of OmtA in fungal colonies grown on a solid medium that supports both toxin synthesis and conidiation. OmtA-specific polyclonal antibodies were purified by affinity chromatography using an LW1432 protein extract. OmtA was not detected in 24-h-old colonies but was detected in 48-h-old colonies using Western blot analysis; the protein accumulated in all fractions of a 72-h-old colony, including cells (0 to 24 h) in which little conidiophore development was observed. OmtA in older fractions of the colony (24 to 72 h) was partly degraded. Fluorescence-based immunohistochemical analysis conducted on thin sections of paraffin-embedded fungal cells from time-fractionated fungal colonies demonstrated that OmtA is evenly distributed among different cell types and is not concentrated in conidiophores. These data suggest that OmtA is present in newly formed fungal tissue and then is proteolytically cleaved as cells in that section of the colony age.
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Affiliation(s)
- Li-Wei Lee
- Department of Food Science and Human Nutrition, Michigan State University, East Lansing, Michigan 48824, USA
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