Bioactive Resorcylic Acid Lactones with Different Ring Systems from Desert Plant Endophytic Fungus Chaetosphaeronema hispidulur

Abstract

Five new resorcylic acid lactones (RALs) hispidulactones A-E (1, 4, 5, 8, and 9), a new natural product (2), and four known ones (3, 6, 7, and 10) with different ring systems were isolated from the desert plant endophytic fungus Chaetosphaeronema hispidulur. The new compounds were characterized by NMR data, CD spectra, and X-ray experiment. The new natural product (2) displayed strongly biological effects on the seedlings growth of Arabidopsis thaliana, Digitaria sanguinalis, and Echinochloa crusgalli with a dose-dependent relationship. Compounds 1, 2, and 6 were also tested cytotoxic activities against three cancer cell lines HCT116, Hela, and MCF7 and only did the new natural product (2) display biological activities with IC values at 54.86 ± 1.52, 4. 90 ± 0.02, and 20.04 ± 4.00 μM, respectively, whereas the IC values of the positive control cis-platinum were 11.36 ± 0.42, 3.54 ± 0.12, and 14.32 ± 1.01 μM, respectively.

Chaetomadrasins A and B, Two New Cytotoxic Cytochalasans from Desert Soil-Derived Fungus Chaetomium madrasense 375

“…In our continued discovery of bioactive natural products from the members of special fungi isolated from the desert and grasslands inhabiting the Northwest of China [16,17,18,19], two new cytochalasan derivatives, Chaetomadrasins A ( 1 ) and B ( 2 ), together with six related known compounds ( 3 – 8 ) (Figure 1), were isolated and identified from the ethyl acetate extract of a solid-state fermented culture of Chaetomium madrasense 375, which was collected from desert soil in Hotan city, Sinkiang province, People’s Republic of China. However, as far as we know, this is the first report on secondary metabolites from the fungi.…”

Herbicidal Polyketides and Diketopiperazine Derivatives fromPenicillium viridicatum

“…E. crusgalli and A. retroflexus belong to the representative monocotyledonous and dicotyledonous malignant weed, respectively, which was widely distributed and seriously destructive in the field. Therefore, the two weeds were usually used to evaluate the herbicidal potentials of various natural or synthetic compounds. , …”

“…Synthetic herbicides have been proven to be the reliable and economical strategies for weed control over the past decades . However, their ongoing and unrestricted applications have led to increased human health risks, environmental pollution, and, more seriously, the evolution of resistant weeds. , Therefore, the development of bioherbicides from natural products has attracted increased attentions due to their environmental friendliness, high selectivity, and probable new target sites. − …”

Rhinoclactones A-E, Resorcylic Acid Analogs from Desert Plant Endophytic Fungus Rhinocladiella similis

“…Resorcylic lactone analogs (such as radicicol) also display a wide range of biological activities, including inhibition of Hsp90 and kinases, antimicrobial, cytotoxic and anti-inflammatory effects [1,5,6,7,8]. Recently, our lab initiated chemical investigation of endophytes collected from desert, arid and grassland areas of West China [9,10,11,12,13,14,15]. In order to further mine new/novel and bioactive secondary metabolites from this special member of fungi, seven RAL analogs ( 1 – 7 ), including five new varieties ( 1 , 2 , 4 – 6 ) with different modifications on the macrolactone ring and phenolic ring, were isolated from an endophytic fungus Rhinocladiella similis from the plant Agriophyllum squarrosum (L.) Moq.…”