Efficient synthesis and characterization of ergosterol laurate in a solvent-free system

Enzymatic synthesis and characterization of novel lipophilic inotodiol-oleic acid conjugates

In this study, we establish an efficient enzymatic approach for producing novel inotodiyl-oleates (IOs) from pure inotodiol and oleic acid to improve the properties of inotodiol. For the esterification between inotodiol and oleic acid, CALA and n-hexane were the optimal biocatalyst and solvents for forming IOs with 80.17% conversion yield. These IOs comprised two distinct monoesters, the C3 or C22 ester forms of inotodiol. Intriguingly, no diesters were detected. The IOs had a melting point of 53.48 °C, much lower than that of inotodiol (192.06 °C). The in vitro digestion rate of IOs (25-28%) was significantly (p < 0.05) lower than that of cholesteryl-oleate (60%). Additionally, IOs exhibited much lower in vivo absorption than inotodiol when orally administered using different formulations (p < 0.05). The results indicated that IOs were resistant to enzymatic digestion in the small intestine, which could be advantageous in targeting the large intestine for disease treatments.

Improved antioxidant activity of rutin via lipase-mediated esterification with oleic acid

BACKGROUND

Oxidation is a major problem for oils and fats, which can be mitigated by antioxidants. Rutin has excellent antioxidant activity, but its poor lipid solubility greatly limits its practical application. In this study, an efficient enzymatic synthesis route of lipophilic rutin ester was established using oleic acid as an acyl donor, and the antioxidant potential of rutin oleate was evaluated for the first time by proton (¹ H) nuclear magnetic resonance (NMR) spectroscopy.

RESULTS

The synthesized product was finally identified as rutin oleate by Fourier transform infrared, high-performance liquid chromatography-mass spectrometry, and ¹ H, carbon-13, and DEPT-135 NMR analyses, and the acylation site was the 4‴-OH of the rhamnose group in the rutin molecule. The maximum conversion was over 93% after 48 h of reaction using Novozym 435 as catalyst under the best conditions among these tests. The conversion of rutin ester decreased with the increase of carbon chain length and the number of carbon-carbon double bonds of the fatty acid molecule. Most importantly, rutin oleate exhibited antioxidant capacity comparable to butylated hydroxytoluene and its counterparts (rutin and oleic acid) at low temperatures (60° C), but had a significant advantage at high temperatures (120° C).

CONCLUSION

The antioxidant activity of rutin was significantly enhanced by lipase-mediated esterification with oleic acid. Therefore, rutin oleate could be further developed as a novel antioxidant for use in oil- and fat-based foods. © 2023 Society of Chemical Industry.

Enhanced antioxidant capacity of lipoic acid in different food systems through lipase-mediated esterification with phytosterols

BACKGROUND

α-Lipoic acid has excellent antioxidant activity, but its poor lipid solubility greatly limits its practical application. This study was undertaken (i) to develop a novel and efficient enzymatic synthesis of lipophilic lipoic acid esters using Candida sp. 99-125 lipase as a catalyst; and (ii) to systematically evaluate their antioxidant potential against bulk oil, oil-in-water emulsion (O/W) and cooked ground meat.

RESULTS

Lipophilic lipoic acid esters were successfully and efficiently synthesized using phytosterols as acyl receptor in the presence of Candida sp. 99-125 lipase. The product was identified as phytosterol lipoate by mass spectrometry, Fourier transform infrared spectroscopy and nuclear magnetic resonance. The maximum conversion of phytosterol lipoate surpassed 90% within 12 h and its final yield exceeded 81%. Interestingly, the oil solubility of lipoic acid was increased at least 25-fold and other physicochemical properties were significantly improved. Most importantly, phytosterol lipoate exhibited higher antioxidant activity than lipoic acid in bulk oil, O/W emulsions and cooked ground meat.

CONCLUSION

The antioxidant capacity of lipoic acid can be significantly enhanced by esterification with phytosterols. Therefore, phytosterol lipoate could be further developed as a new antioxidant for use in oil- and fat-based foods. © 2022 Society of Chemical Industry.

Structure and Biological Activity of Ergostane-Type Steroids from Fungi

Mushrooms are known not only for their taste but also for beneficial effects on health attributed to plethora of constituents. All mushrooms belong to the kingdom of fungi, which also includes yeasts and molds. Each year, hundreds of new metabolites of the main fungal sterol, ergosterol, are isolated from fungal sources. As a rule, further testing is carried out for their biological effects, and many of the isolated compounds exhibit one or another activity. This study aims to review recent literature (mainly over the past 10 years, selected older works are discussed for consistency purposes) on the structures and bioactivities of fungal metabolites of ergosterol. The review is not exhaustive in its coverage of structures found in fungi. Rather, it focuses solely on discussing compounds that have shown some biological activity with potential pharmacological utility.

Potential role of mycosterols in hyperlipidemia - A review

Cardiovascular diseases associated with obesity are alarmingly increasing in both developed and developing countries. Obesity is mainly ascribed to higher lipid accumulation in the body. There are several simple approaches to treat this condition like lifestyle modification, dietary intervention, physical activities, drug treatment etc. There are many drugs available in the market to treat hyperlipidemia condition, but those drugs have many fatal adverse effects on human health. In view of this, it is reasonable to suggest some preventive measures by functional food ingredients as human health has acclimatized to these since thousands of years. Phytosterols have been studied since decades for its hypocholesterolemic effect in human nutrition. Although the mycosterols from fungi are still under- exploited, ergosterol and derivatives from fungal source have promising health beneficial effects in obesity associated cardiovascular diseases. This review aims to summarise the investigations on mycosterol with respect to obesity in the last decade and also scope of future research on its application in functional food supplements.

Liquid chromatography-tandem mass spectrometry is effective for analysis of ergosterol in fungal-infected nails

BACKGROUND

Identification of onychomycosis is mainly based on clinical diagnosis with auxiliary diagnostic methods such as potassium hydroxide (KOH) microscopy, periodic acid-Schiff staining or fungal culture. However, each method is limited by its sensitivity and specificity.

AIM

To develop a new test method using the common fungal end product, ergosterol, and investigate if it can be used as a new diagnostic tool.

METHODS

We collected consecutive data from 20 participants with nail problems. Following clinical diagnosis, samples were taken for KOH microscopy and for mass spectrometry (MS) to check for the presence of ergosterol.

RESULTS

Of the 20 cases collected, 7 were positive for fungal infection by MS. Four of these were already suspected to have onychomycosis, whereas one of the remaining three subjects was presumed to have dry nail and the other two to have onycholysis. The MS test seemed to be better at detecting combinations of nail conditions. Conversely, of the five patients clinically diagnosed as having onychomycosis, four had a positive MS result, whereas the fifth had negative results on both KOH and MS. Two other participants had a positive KOH test and were also found to have positive MS results.

CONCLUSION

Detection of the presence of ergosterol by MS seems to be a useful tool for confirming onychomycosis. However, further studies are needed to verify the sensitivity and specificity of this MS method.

Preparation, Antidermatophyte Activity, and Mechanism of Methylphloroglucinol Derivatives

In this study a variety of phloroglucinols were isolated from the plant, and the activity experiment showed that the phloroglucinols had strong antifungal activity, especially methylphloroglucinol derivatives such as aspidin PB, dryofragin, aspidinol, aspidin BB, aspidin AB, and albicanol, in which the hydroxyl group of methylphloroglucinol is the active group of compounds, and C-2 or C-6 is the active site. The introduction of different groups in this position could change the properties and bioactivity of the compounds. In this study, different functional groups were introduced to the structure of methylphloroglucinol to obtain methylphloroglucinol derivatives that were synthesized, and antidermatophyte activities on Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum canis, and Gypsum microspore bacteria were evaluated. Molecular docking verified its ability to combine the protein binding site. The antidermatophyte mechanism of compounds on cytochrome P450 sterol 14a-demethylase, squalene epoxidase, and β-1,3-glucan synthase was investigated by the enzyme-linked immunosorbent assay. The results showed that compounds had an inhibitory effect on four kinds of common dermatophytes in varying degrees, in which compound g had the strongest activities, the binding mode of methylphloroglucinol and its derivatives were similar to those of three enzymes, and compounds e and g had significant effects on the activity of the three enzymes, and compound g had a slightly stronger effect than the blank group. Compounds e and g also had a significant effect on the ergosterol synthesis of M. canis. This study could supply some antidermatophyte leading structure and possible mechanism for studying and developing new antifungal agents.