Taxonomy Driven Discovery of Polyketides from Aspergillus californicus

Abstract

Five new polyketides were isolated from the rare filamentous fungus Aspergillus californicus IBT 16748 including calidiol A (1); three phthalide derivatives califuranones A1, A2, and B (2–4); and a pair of enantiomers (−)-calitetralintriol A (−5) and (+)-calitetralintriol A (+5) together with four known metabolites (6–9). The structures of the new products were established by extensive spectroscopic analyses including HRMS and 1D and 2D NMR. The absolute configurations of two diastereomers 2 and 3 and the enantiomers (−5) and (+5) were assigned by comparing their experimental and calculated ECD data, whereas the absolute configuration of 4 was proposed by analogy. Compound 1 showed moderate activity against methicillin-resistant Staphylococcus aureus.

Synthesis, reactions and application of chalcones: a systematic review

“…Also, for the disciplines of pharmaceutical and drug discovery studies, heterocycles are crucial pharmacophores. [1][2][3] Ancient Egyptians, Chinese, and Mesopotamians recorded a variety of plant-based medicines that are still in use today. 4,5 Due to several inherent challenges with natural product drug development, the pharmaceutical industry has changed its focus from natural products to synthetic compound libraries and high-throughput screening (HTS) for the purpose of finding pharmacological leads.…”

Probing Molecular Chirality of Ground and Electronically Excited States in the UV–vis and X-ray Regimes: An EOM-CCSD Study

“…10,11 The key step in contemporary use of spectroscopy for chiral discrimination is the simulation of the spectra for an a priori chosen absolute configuration of the chiral species. 12,13 Indeed, experimental measurements of optical activity alone are not sufficient to establish the absolute configuration, since there is no direct correspondence between the enantiomer's configuration and the measured sign of the chiroptical property. However, if the simulated spectrum of the chosen configuration matches the sign pattern of the measured spectrum, one can conclude that the experimental sample contains the same enantiomer as in the simulation, 5,12−14 provided, of course, that the computational method is reliable.…”

Probing Molecular Chirality of Ground and Electronically Excited States in the UV-vis and X-ray Regimes: An EOM-CCSD Study

“…10,11 The key step in contemporary use of spectroscopy for chiral discrimination is the simulation of the spectra for an a priori chosen absolute configuration of the chiral species. 12,13 Indeed, experimental measurements of optical activity alone are not sufficient to establish the absolute configuration, since there is no direct correspondence between the enantiomer's configuration and the measured sign of the chiroptical property. However, if the simulated spectrum of the chosen configuration matches the sign pattern of the measured spectrum, one can conclude that the experimental sample contains the same enantiomer as in the simulation, 5,[12][13][14] provided, of course, that the computational method is reliable.…”