Novel kojic acid derivatives with anti-inflammatory effects from Aspergillus versicolor

Secondary Metabolites from the Coral-Derived Fungus Aspergillus austwickii SCSIO41227 with Pancreatic Lipase and Neuraminidase Inhibitory Activities

The coral-derived fungus Aspergillus austwickii SCSIO41227 from Beibu Gulf yielded four previously uncharacterized compounds, namely asperpentenones B-E (1-4), along with twelve known compounds (5-16). Their structures were elucidated using HRESIMS and NMR (1H and 13C NMR, HSQC, HMBC), among which the stereo-structure of compounds 1-3 was determined by calculated ECD. Furthermore, compounds 1-16 were evaluated in terms of their enzyme (acetylcholinesterase (AChE), pancreatic lipase (PL), and neuraminidase (NA)) inhibitory activities. These bioassay results revealed that compounds 2 and 14 exerted noticeable NA inhibitory effects, with IC50 values of 31.28 and 73.64 μM, respectively. In addition, compound 3 exhibited a weak inhibitory effect against PL. Furthermore, these compounds showed the potential of inhibiting enzymes in silico docking analysis to demonstrate the interactions between compounds and proteins.

Characterization of the Biosynthetic Gene Cluster for the Ribosomally Synthesized Cyclic Peptide Epichloëcyclins in Epichloë festucae

The various grass-induced epichloëcyclins of the Epichloë spp. are ribosomally synthesized and post-translationally modified peptides (RiPPs), produced as small, secreted cyclopeptides from a single gene, gigA. Here, four clustered and coregulated genes (gigA, gigB, gigC, and kexB) with predicted roles in epichloëcyclin production in Epichloë festucae were evaluated through gene disruption. Subsequent chemical analysis indicates that GigB is a DUF3328 domain-containing protein associated with cyclization of epichloëcyclins; GigC is a methyltransferase enzyme responsible for N-methylation of desmethylepichloëcyclins; and KexB is a subtilisin-like enzyme, partly responsible for the propeptide cleavage of epichloëcyclin intermediates. Symbiotic effects on the host phenotype were not observed for gigA, gigC, or kexB mutants, although ΔgigB infection correlated with increased host tiller height and biomass, while only ΔkexB exhibited an effect on endophyte morphology. Disrupting epichloëcyclin biosynthesis showed negligible influence on the biosynthesis of E. festucae-associated alkaloids. Epichloëcyclins may perform other secondary metabolism functions in Epichloë and other fungi.

Skin Pigmentation Types, Causes and Treatment-A Review

Human skin pigmentation and melanin synthesis are incredibly variable, and are impacted by genetics, UV exposure, and some drugs. Patients' physical appearance, psychological health, and social functioning are all impacted by a sizable number of skin conditions that cause pigmentary abnormalities. Hyperpigmentation, where pigment appears to overflow, and hypopigmentation, where pigment is reduced, are the two major classifications of skin pigmentation. Albinism, melasma, vitiligo, Addison's disease, and post-inflammatory hyperpigmentation, which can be brought on by eczema, acne vulgaris, and drug interactions, are the most common skin pigmentation disorders in clinical practice. Anti-inflammatory medications, antioxidants, and medications that inhibit tyrosinase, which prevents the production of melanin, are all possible treatments for pigmentation problems. Skin pigmentation can be treated orally and topically with medications, herbal remedies, and cosmetic products, but a doctor should always be consulted before beginning any new medicine or treatment plan. This review article explores the numerous types of pigmentation problems, their causes, and treatments, as well as the 25 plants, 4 marine species, and 17 topical and oral medications now on the market that have been clinically tested to treat skin diseases.

Fungal production of kojic acid and its industrial applications

Kojic acid has gained its importance after it was known worldwide that the substance functions primarily as skin-lightening agent. Kojic acid plays a vital role in skin care products, as it enhances the ability to prevent exposure to UV radiation. It inhibits the tyrosinase formation which suppresses hyperpigmentation in human skin. Besides cosmetics, kojic acid is also greatly used in food, agriculture, and pharmaceuticals industries. Conversely, according to Global Industry Analysts, the Middle East, Asia, and in Africa especially, the demand of whitening cream is very high, and probably the market will reach to $31.2 billion by 2024 from $17.9 billion of 2017. The important kojic acid-producing strains were mainly belongs to the genus Aspergillus and Penicillium. Due to its commercial potential, it continues to attract the attention for its green synthesis, and the studies are still widely conducted to improve kojic acid production. Thus, the present review is focused on the current production processes, gene regulation, and limitation of its commercial production, probable reasons, and possible solutions. For the first time, detailed information on the metabolic pathway and the genes involved in kojic acid production, along with illustrations of genes, are highlighted in the present review. Demand and market applications of kojic acid and its regulatory approvals for its safer use are also discussed. KEY POINTS: • Kojic acid is an organic acid that is primarily produced by Aspergillus species. • It is mainly used in the field of health care and cosmetic industries. • Kojic acid and its derivatives seem to be safe molecules for human use.

Effective production of kojic acid in engineered Aspergillus niger

BACKGROUND

Kojic acid (KA) is a widely used compound in the cosmetic, medical, and food industries, and is typically produced by Aspergillus oryzae. To meet increasing market demand, it is important to optimize KA production through seeking alternatives that are more economic than current A. oryzae-based methods.

RESULTS

In this study, we achieved the first successful heterologous production of KA in Aspergillus niger, an industrially important fungus that does not naturally produce KA, through the expression of the kojA gene from A. oryzae. Using the resulting KA-producing A. niger strain as a platform, we identified four genes (nrkA, nrkB, nrkC, and nrkD) that negatively regulate KA production. Knocking down nrkA or deleting any of the other three genes resulted in a significant increase in KA production in shaking flask cultivation. The highest KA titer (25.71 g/L) was achieved in a pH controlled batch bioreactor using the kojA overexpression strain with a deletion of nrkC, which showed a 26.7% improvement compared to the KA titer (20.29 g/L) that was achieved in shaking flask cultivation.

CONCLUSION

Our study demonstrates the potential of using A. niger as a platform for studying KA biosynthesis and regulation, and for the cost-effective production of KA in industrial strain development.

Anti-inflammatory compounds from the mangrove endophytic fungus Amorosia sp. SCSIO 41026

Three new chlorinated compounds, including two propenylphenol derivatives, chlorophenol A and B (1 and 2), and one benzofuran derivative, chlorophenol C (3), together with 16 known compounds, were isolated from the mangrove endophytic fungus Amorosia sp. SCSIO 41026. 7-Chloro-3,4-dihydro-6,8-dihydroxy-3-methylisocoumarine (4) and 2,4-dichloro-3-hydroxy-5-methoxy-toluene (5) were obtained as new natural products. Their structures were elucidated by physicochemical properties and extensive spectroscopic analysis. Compounds 1, 4, 7, 9, 13, 15, 16, and 19 possessed inhibitory effects against the excessive production of nitric oxide (NO) and pro-inflammatory cytokines in lipopolysaccharide (LPS)-challenged RAW264.7 macrophages without obvious cytotoxicity. Moreover, 5-chloro-6-hydroxymellein (13) further alleviated the pathological lung injury of LPS-administrated mice and protected RAW264.7 macrophages against LPS-induced inflammation through PI3K/AKT pathway in vivo. Our research laid the foundation for the application of compound 13 as a potential anti-inflammatory candidate.

Biological activities and safety data of kojic acid and its derivatives - a review

Kojic acid presents a variety of applications for human use, especially as a depigmenting agent. Its derivatives are also proposed in order to prevent chemical degradation, prevent adverse effects and improve efficacy. The aim of this study was to peer review the current scientific literature concerning the biological activities and safety data of kojic acid or its derivatives, aiming at human use, and trying to elucidate the action mechanisms. Three different databases were assessed and the word "kojic" was crossed with "toxicity", "adverse effect", "efficacy", "effect", "activity" and "safety". Articles were selected according to pre-defined criteria. Besides the depigmenting activity, kojic acid and derivatives can act as antioxidant, antimicrobial, anti-inflammatory, radioprotector, anticonvulsant and obesity management agents, and present potential as antitumor substances. Depigmenting activity is due to the molecules, after penetrating the cell, binding to tyrosinase active site, regulating melanogenesis factors, leucocytes modulation and free radical scavenging activity. Hence, polarity, size and ligands are also important factors for activity. Kojic acid and derivatives present cytotoxicity to some cancerous cell lines, including melanoma, hepatocellular carcinoma, ovarian cancer, breast cancer and colon cancer. Regarding safety, kojic acid or its derivatives are safe molecules for human use in the concentrations tested. Kojic acid and its derivatives have great potential for cosmetic, pharmaceutical and medical applications.

Review on the Use of Kojic Acid—A Skin-Lightening Ingredient

This article reviews the use of Kojic Acid (KA) as a skin-lightening ingredient in the cosmetics industry. In 1907, Saito discovered KA, a natural product; it has since become one of the most investigated skin-lightening agents. This paper highlights the findings of the research conducted on this agent. It has been found that KA has certain disadvantages, and researchers have attempted to mitigate these disadvantages by designing new equivalents of KA that are more efficient in tyrosinase inhibition. These equivalents are also safe to use and have improved properties and solubility. The Cosmeceutical Ingredient Review (CIR) indicates that this ingredient can be safely used at a concentration not higher than 1% due to its cytotoxicity. Other scientific data also support its safety at a concentration of 2% or less. It was shown to be helpful in the treatment of hyper pigmentary disorders, such as freckles, age spots, post-inflammatory hyperpigmentation, and melasma, which has been proven clinically.

Technologies for Solubility, Dissolution and Permeation Enhancement of Natural Compounds

The current review is based on the advancements in the field of natural therapeutic agents which could be utilized for a variety of biomedical applications and against various diseases and ailments. In addition, several obstacles have to be circumvented to achieve the desired therapeutic effectiveness, among which limited dissolution and/or solubility and permeability are included. To counteract these issues, several advancements in the field of natural therapeutic substances needed to be addressed. Therefore, in this review, the possible techniques for the dissolution/solubility and permeability improvements have been addressed which could enhance the dissolution and permeability up to several times. In addition, the conventional and modern isolation and purification techniques have been emphasized to achieve the isolation and purification of single or multiple therapeutic constituents with convenience and smarter approaches. Moreover, a brief overview of advanced natural compounds with multiple therapeutic effectiveness have also been anticipated. In brief, enough advancements have been carried out to achieve safe, effective and economic use of natural medicinal agents with improved stability, handling and storage.

Metabolic Profiling and In Vitro Assessment of the Biological Activities of the Ethyl Acetate Extract of Penicillium chrysogenum “Endozoic of Cliona sp. Marine Sponge” from the Red Sea (Egypt)

Marine sponge-derived endozoic fungi have been gaining increasing importance as promising sources of numerous and unique bioactive compounds. This study investigates the phytochemical profile and biological activities of the ethyl acetate extract of Penicillium chrysogenum derived from Cliona sp. sponge. Thirty-six compounds were tentatively identified from P. chrysogenum ethyl acetate extract along with the kojic acid (KA) isolation. The UPLC-ESI-MS/MS positive ionization mode was used to analyze and identify the extract constituents while 1D and 2D NMR spectroscopy were used for kojic acid (KA) structure confirmation. The antimicrobial, antioxidant, and cytotoxic activities were assessed in vitro. Both the extract and kojic acid showed potent antibacterial activity against Staphylococcus aureus and Pseudomonas aeruginosa with MIC 250 ± 0.82 µg/mL. Interestingly, the extract showed strong antifungal activity against Candida albicans and Cryptococcus neoformans with MIC 93.75 ± 0.55 and 19.53 ± 0.48 µg/mL, respectively. Furthermore, KA showed the same potency against Fusarium oxysporum and Cryptococcus neoformans with MIC 39.06 ± 0.85 and 39.06 ± 0.98 µg/mL, respectively. Ultimately, KA showed strong antioxidant activity with IC₅₀ 33.7 ± 0.8 µg/mL. Moreover, the extract and KA showed strong cytotoxic activity against colon carcinoma (with IC₅₀ 22.6 ± 0.8 and 23.4 ± 1.4 µg/mL, respectively) and human larynx carcinoma (with equal IC₅₀ 30.8 ± 1.3 and ± 2.1 µg/mL, respectively), respectively. The current study represents the first insights into the phytochemical profile and biological properties of P. chrysoenum ethyl acetate extract, which could be a promising source of valuable secondary metabolites with potent biological potentials.