Chlorotheolides A and B, Spiroketals Generated via Diels–Alder Reactions in the Endophytic Fungus Pestalotiopsis theae

Abstract

Chlorotheolides A (1) and B (2), two new spiroketals possessing the unique [4,7]methanochromene and dispiro-trione skeletons, respectively, and their putative biosynthetic precursors, 1-undecen-2,3-dicarboxylic acid (3) and maldoxin (4), were isolated from the solid substrate fermentation of the plant endophytic fungus Pestalotiopsis theae (N635). Their structures were elucidated based on NMR spectroscopic data and electronic circular dichroism calculations. Biogenetically, compounds 1 and 2 could be generated from the co-isolated 3 and 4 via Diels-Alder reactions. Chlorotheolide (2) showed an antiproliferative effect against the human tumor cell line HeLa and induced an autophagic process in the cells.

The sporothriolides. A new biosynthetic family of fungal secondary metabolites

“…21 Decanoyl CoA 17 is likely to be reacted with oxaloacetate by CS, in analogy to other known pathways, 6 to give an octanyl citrate 18 which is then dehydrated to give octanyl aconitate 19 and decarboxylated to the rst observable intermediate, octanyl itaconic acid 20, a known compound from the endophytic fungus Pestalotiopsis theae. 22 The R absolute conguration at C-2 was conrmed by comparing the optical rotation with literature (see ESI Table S3.12 †). 22 The addition of the putative dioxygenase spoG to the previous set of genes in A. oryzae results in formation of a broad range of new compounds in addition to 20 (EXP 5, Fig.…”

“…22 The R absolute conguration at C-2 was conrmed by comparing the optical rotation with literature (see ESI Table S3.12 †). 22 The addition of the putative dioxygenase spoG to the previous set of genes in A. oryzae results in formation of a broad range of new compounds in addition to 20 (EXP 5, Fig. 6B).…”

Endophytic Actinomycetes from Tea Plants (Camellia sinensis): Isolation, Abundance, Antimicrobial, and Plant-Growth-Promoting Activities

“…Whereas tea phytochemicals and their beneficial effects have been well characterized, studies on tea plant endophytes are rather scarce. Chemical investigations of Pestalotiopsis spp., fungi which are endophytic to C. sinensis , have led to the discovery of an array of bioactive natural products with unique structural features [ 25 – 29 ]. In another study, 10 butenolides were obtained from an Aspergillus terreus strain isolated from C. sinensis var.…”

Optimization of Submerged Fermentation Medium for Matrine Production by Aspergillus terreus, an Endophytic Fungus Harboring Seeds of Sophora flavescens, Using Response Surface Methodology

“…With the report of Stierle et al [ 22 ] on taxol production by endophyte Taxomyces andreanae , a host of researchers were interested in bioprospecting of endophytes for secondary metabolites and got some breakthrough [ 23 24 25 ]. In present study, five strains were isolate from the seeds of S. flavescens .…”