Abstract

Objective: To document differential distributions of phytomolecules by comparing antioxidant capacities, total phenolic contents, flavonoid contents and the identities of bioactive molecules on four phases of Pleurotus djamor. Methods: Several methods including in vitro quantitative methods such as aluminium chloride spectrophotometric for flavonoids, Folin-Ciocalteu assay for phenolics, spectrometric methods for lycopene, β-carotene and carotenoids, and several antioxidant methods, ferric ion reducing antioxidant power assay (FRAP); 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS); and 1,1-diphenyl-2-picrylhydrazyl (DPPH), were used. Besides, liquid chromatography quadrupole time-of-flight mass spectrometry and ChemSpider database for the tentative identification of the compounds was utilized. Results: The total phenol contents in the 1st and 2nd primordial phases from ethanol and aqueous extracts were (14.369 ± 0.495), (11.470 ± 0.532) and (19.025 ± 0.847) and (14.824 ± 0.890) mg gallic acid equivalent/g dry weight, respectively. The total flavonoid contents ranged from (3.311 ± 0.730) to (14.824 ± 0.890) mg quercetin equivalent/g dry weight. The second primordials phase recorded the highest total carotenoid content [(3.926 ± 0.059) ug/mL dry weight]. The extracts were deprived of lycopene, β-carotene and total carotenoids. However, the primordials reported relatively high contents of all molecules tested. The antioxidant capacity based on FRAP, ABTS and DPPH assays showed that the primordials exhibited more significant capacities in scavenging for these radicals than the mycelia and fruiting phases. The correlation between FRAP, ABTS, DPPH and total phenolic content, total flavonoid content, lycopene, β-carotene were positive and significant (r > 0.8, P < 0.05). Liquid chromatography quadrupole time-of-flight mass spectrometry analysis identified sixteen compounds using ChemSpide database. Phenolic acids, such as protocatechuic, hydroxycinnamic acid and stilbenes, and the flavonoids belonging to flavones, flavanones, isoflavone and anthocyanins were identified. The peak areas indicated significantly higher contents in the primordials phases for all compounds. Conclusions: The immature basidiocarps are potent sources of secondary metabolites that should be targeted for in vivo validation of their function in such systems.

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