In the urgent search for more effective ways to treat cancer, new extraction methods of taxol from endophytic fungus have demonstrated high potential in increasing the efficiency of taxol extraction for more efficient and sustainable production of taxol and cancer treatment products. This paper summarizes recent advances in taxol-producing endophytic fungi, both in China and abroad, in the following areas: isolation and identification of endophytic fungi types, extraction and detection methods of endophytic taxol in plants, and improved efficiency of the extraction process. With the advancement of science and technology, new techniques in biotechnology, such as fungal strain improvement and recombining technique and microbial fermentation engineering, have increased the extraction yield from taxol-producing fungi, thereby improved the overall efficiency of taxol production.
Asperchalasine A (1), the first cytochalasan dimer featuring a unique decacyclic 5/6/11/5/5/6/5/11/6/5 ring system consisting of 20 chiral centers, was isolated from the culture broth of Aspergillus flavipes. Three biogenetically related intermediates, asperchalasines B-D (2-4), were also isolated. Their structures, including their absolute configurations, were elucidated using a combination of HRESIMS, NMR, ECD, molecular modeling, and single-crystal X-ray diffraction techniques. Compound 1, which possesses an unprecedented 13-oxatetracyclo[7.2.1.1(2,5).0(1,6)]tridec-8,12-dione core structure, is the first example of a dimeric cytochalasan alkaloid. The biogenetic pathways of 1-4 were described starting from the co-isolated compounds 5 and 6. More importantly, 1 induced significant G1-phase cell cycle arrest by selectively inhibiting cyclin A, CDK2 and CDK6 in cancerous, but not normal, cells, highlighting it as a potentially selective cell cycle regulator against cancer cells.
Asperflavipines A (1) and B (2), two structurally complex merocytochalasans, were isolated from Aspergillus flavipes. Asperflavipine A (1), which contains two cytochalasan moieties and two epicoccine moieties, is the first cytochalasan heterotetramer to be discovered. It is uniquely defined by 5/6/11/5/6/5/6/5/6/5/5/11/6/5 fused tetradecacyclic rings with three continuous bridged ring systems. Asperflavipine B (2) is a cytochalasan heterotrimer containing a cytochalasan and two epicoccine moieties with a 5/6/11/5/5/6/5/6/5 nonacyclic ring system. The hypothetical biosynthesis of 1 and 2 is proposed to involve Diels-Alder and [3+2] cycloaddition reactions as key steps and reveals unparalleled plasticity in the biosynthesis of merocytochalasans. The existence of 1 adds a new dimension to the diversity of the cytochalasan family. Compound 1 showed moderate cytotoxicity and induced apoptosis in Jurkat, NB4, and HL60 cells through the activation of caspase-3 and degradation of poly(ADP-ribose) polymerase (PARP).
Bioassay-guided isolation of cultures of Aspergillus sp. TJ23 yielded a novel terpene-polyketide hybrid spiromeroterpenoid, spiroaspertrione A (1), bearing a unique spiro[bicyclo[3.2.2]nonane-2,1'-cyclohexane] carbocyclic skeleton, and a new biointermediate, andiconin B (2). Their structures and absolute configurations were elucidated by spectroscopic analyses, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Compound 1 demonstrated potent resensitization of oxacillin against methicillin-resistant Staphylococcus aureus by lowering the oxacillin minimal inhibitory concentration up to 32-fold from 32 to 1 μg/mL.
BackgroundThe Orchidaceae is one of the largest families in the plant kingdom and orchid mycorrhizae (OM) are indispensable in the life cycle of all orchids under natural conditions. In spite of this, little is known concerning the mechanisms underlying orchid- mycorrhizal fungi interactions. Our previous work demonstrated that the non-mycorrhizal fungus Umbelopsis nana ZH3A-3 could improve the symbiotic effects of orchid mycorrhizal fungus Epulorhiza repens ML01 by co-cultivation with Cymbidium hybridum plantlets. Thus, we investigated the C. hybridum transcript profile associated with different beneficial fungi.ResultsMore than 54,993,972 clean reads were obtained from un-normalized cDNA library prepared from fungal- and mock- treated Cymbidium roots at four time points using RNA-seq technology. These reads were assembled into 16,798 unique transcripts, with a mean length of 1127 bp. A total of 10,971 (65.31%) sequences were annotated based on BLASTX results and over ninety percent of which were assigned to plant origin. The digital gene expression profiles in Cymbidium root at 15 days post inoculation revealed that 1674, 845 and 1743 genes were sigificantly regulated in response to ML01, ZH3A-3 and ML01+ ZH3A-3 treatments, respectively. Twenty-six genes in different regulation patterns were validated using quantitative RT-PCR. Our analysis showed that general defense responses were co- induced by three treatments, including cell wall modification, reactive oxygen species detoxification, secondary biosynthesis and hormone balance. Genes involved in phosphate transport and root morphogenesis were also detected to be up-regulated collectively. Among the OM specifically induced transcripts, genes related to signaling, protein metabolism and processing, defense, transport and auxin response were identifed. Aside from these orchid transcripts, some putative fungal genes were also identified in symbiotic roots related to plant cell wall degradation, remodeling the fungal cell wall and nutrient transport.ConclusionThe orchid root transcriptome will facilitate our understanding of orchid - associated biological mechanism. The comparative expression profiling revealed that the transcriptional reprogramming by OM symbiosis generally overlapped that of arbuscular mycorrhizas and ectomycorrhizas. The molecular basis of OM formation and function will improve our knowledge of plant- mycorrhzial fungi interactions, and their effects on plant and fungal growth, development and differentiation.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-747) contains supplementary material, which is available to authorized users.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.