Five new secondary metabolites from an endophytic fungus Phomopsis sp. SZSJ-7B

Abstract

Two previously undescribed lactones, phomolides A and B (1 and 2), and three new sesquiterpenoids, phomenes A–C (3–5), together with one known compound, colletotricholide A (6), were isolated from the endophytic fungus Phomopsis sp. SZSJ-7B. Their chemical structures, including the absolute configurations, were comprehensively established by extensive analyses of NMR, high-resolution electrospray ionization mass spectrometry, electronic circular dichroism powered by theoretical calculations, and X-ray diffractions. Moreover, the cytotoxic and antibacterial activities of compounds 1–6 were also evaluated, and the results demonstrated that compound 2 showed significant antibacterial effects towards methicillin-resistant Staphylococcus aureus and S. aureus strains with minimum inhibitory concentration as low as 6.25 μg/ml, which was comparable to that of the clinical drug vancomycin. Moreover, all compounds showed no cytotoxic activity.

Secondary Metabolite Analysis of Phomopsis sp. LGT‐5 Based on the Dual Guidance of Whole‐Genome Sequencing and HPLC‐Q‐ToF‐MS/MS

“…According to the literature investigation, [34][35][36][37] different active chemicals, such as sesquiterpenoids, steroids, isocoumarin, cytochalasins, xanthonesun, and precedented carbon skeletons, have been discovered in specialized metabolites of the fungi Phomopsis sp., and the number and variety of specialized metabolites from the fungal genus Phomopsis are still increasing. However, the identified structures in this study are quite different from the structures reported in the literature because of the fermentation conditions.…”

Koningipyridines A and B, two nitrogen-containing polyketides from the fungus Trichoderma koningiopsis SC-5

“…The conformation search and optimization, DFT GIAO 13 C NMR, and ECD calculations of compounds 1 and 2 were performed as previously described [40]. The detailed computational method, DFT optimized geometry data, relative energies, and conformational population of all calculated structures were attached in the Additional file 1.…”

“…In our ongoing research program focusing on the discovery of biologically meaningful natural products with unique structures from plant-originated fungi [32][33][34][35][36][37][38][39][40], the strain of Trichoderma koningiopsis SC-5 derived from Pedicularis integrifolia was experimentally revealed to produce abundant structurally diverse secondary metabolites as referring to the TLC and HPLC-DAD analyses. The further detailed chemical investigation of Trichoderma koningiopsis SC-5 had led to the isolation of two fascinating koninginin derivatives -koningipyridines A and B (1 and 2), which featured an unprecedented pentacyclic ketal skeleton with the formation of a complex 6/6/5/6/5 fused ring system and a unique 6/6/5 dihydropyridine skeleton, respectively (Fig.…”

Koninginins X-Z, Three New Polyketides from Trichoderma koningiopsis SC-5

“…During our continuing search for novel microbial natural products [23][24][25][26][27], we have previously reported two novel koninginin derivatives sharing unprecedented nitrogenous fused polycyclic polyketide skeletons from Trichoderma koningiopsis SC-5 [28]. With the examination of other similar structurally unique and biologically meaningful koninginins, the further chemical investigation of Trichoderma koningiopsis SC-5 successfully led to the the examination of other similar structurally unique and biologically meaningful koninginins, the further chemical investigation of Trichoderma koningiopsis SC-5 successfully led to the isolation of three novel koninginin derivatives, koninginins X-Z (1-3) (Figure 1).…”