Chemical characterization, pathway enrichments and bioactive potentials of catechin-producing endophytic fungi isolated from tea leaves

• Published in: RSC advances Vol. 14; no. 45; pp. 33034 - 33047
• Main Authors: Sidhu, Dwinder, Vasundhara, M, Dey, Priyankar
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 17-10-2024; The Royal Society of Chemistry
• Subjects: Biochemistry; Biological activity; Biosynthesis; Catechin; Chemistry; Chromatography; Fatty acids; Fungi; Herbal medicine; High performance liquid chromatography; Metabolism; Plant layout; Tea
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d4ra05758a

Endophytes acquire flavonoid biosynthetic genes from the host medicinal plants. Despite tea (
(L.) Kuntze) being the major source of bioactive catechins, catechin-producing endophytic fungi have never been reported from the tea plant. Here, we report the isolation and characterization of catechin-producing endophytic fungi isolated from tea leaves, their chemical characterization, and associated bioactivities. Among the nine isolated endophytes, two (CSPL6 and CSPL5b) produced catechin (381.48 and 166.40 μg per mg extract) and epigallocatechin-
-gallate (EGCG; 484.41 and 281.99 μg per mg extract) as quantified by high-performance liquid chromatography (HPLC). The isolates were identified as
and
based on molecular and morphological characterization. Untargeted metabolomics using gas-chromatography mass spectroscopy (GCMS) revealed the presence of several bioactive phytochemicals mostly belonging to tyrosols, pyridoxines, fatty acids, aminopyrimidine, and benzenetriol classes. Metabolic pathways pertaining to the biosynthesis of unsaturated fatty acids (UFAs), butanoate metabolism, and linoleic acid metabolism were highly enriched in both catechin-producing isolates. The isolates were able to differentially scavenge intracellular O
and N
free-radicals, but CSPL5b demonstrated relatively superior bioactivities compared to CSPL6. Both isolates stimulated the growth of various probiotic strains, indicating prebiotic effects that are otherwise known to be associated with catechins. Collectively, the current study demonstrated that fungal endophytes CSPL6 and CSPL5b, isolated from tea leaves, could be used as alternative sources of catechins, and hold promising potential in evidence-based therapeutics.