Trichodermadiones A and B from the solid culture of Trichoderma atroviride S361, an endophytic fungus in Cephalotaxus fortunei.

Chemical investigation on the solid rice culture of Trichoderma atroviride S361, an endophyte isolated from Cephalotaxus fortunei, has afforded a pair of novel N-furanone amide enantiomers, (-)-trichodermadione A (1a) and (+)-trichodermadione A (1b), and a new cyclohexenone sesquiterpenoid, trichodermadione B (2), together with six known secondary metabolites. Chiral separation of compound 1 was successfully performed on a Lux Cellulose-2 column. Their structures were elucidated by detailed spectroscopic analyses on the basis of NMR, HRMS, and ECD data, and the absolute configurations of the new compounds were determined by computational analyses of their electronic circular dichroism (ECD) spectra and Snatzke's method. Compounds 1a, 1b and 2 were also evaluated for their cytotoxicity against DU145 and PC3 cell lines, as well as inhibitory effects against the production of NO in LPS-stimulated RAW264.7 cells.

An Integrative Approach to Decipher the Chemical Antagonism between the Competing Endophytes Paraconiothyrium variabile and Bacillus subtilis.

An integrative approach combining traditional natural products chemistry, molecular networking, and mass spectrometry imaging has been undertaken to decipher the molecular dialogue between the fungus Paraconiothyrium variabile and the bacterium Bacillus subtilis, which were isolated as endophytes from the conifer Cephalotaxus harringtonia and are characterized by a strong and mutual antibiosis. From this study, we highlight that bacterial surfactins and a fungal tetronic acid are involved in such competition and that the fungus is able to hydrolyze surfactins to fight against the bacterial partner.

Antimicrobial and antitumor activity and diversity of endophytic fungi from traditional Chinese medicinal plant Cephalotaxus hainanensis Li.

Endophytes from Cephalotaxus hainanensis Li, an important source of anti-leukemia drugs, have not been widely explored. In this study, 265 endophytic fungal isolates from C. hainanensis Li were screened for antimicrobial activities against tilapia, banana, rice, and rape and for antitumor activities against human leukemia cell lines (K562, NB4, and HL-60). Diversity was also analyzed. The results showed that 17.7% of the endophytic fungi had antimicrobial activities against at least three different test microbes, and activity against Fusarium oxysporum RKY102 was the highest at 15.8%. Cytotoxicity against at least one tumor cell line tested was observed in 18.5% of the endophytic fungi; with the highest value of 10.6% against K562. The endophytic fungal strains also showed relatively high activities against K562, NB4, and HL-60 while relatively fewer strains were cytotoxic against the human hepatic Hep-G2 and colon LoVo cancer cell lines. Thirty endophytic fungal strains showed both high antimicrobial and antitumor activities. Moreover, the analyses of the diversity of the 30 highly active strains showed they belonged to 20 species from 14 genera, and this is the first report of endophytic fungi Albonectria rigidiuscula, Colletotrichum magnisporum, and Nemania diffusa being isolated from Cephalotaxus plants. These findings suggest that natural antibacterial products for humans and tilapia; antifungal compounds for rice, rape, and banana; and antitumor compounds for leukemia therapy could be isolated from fungal strains derived from C. hainanensis Li.

Homoharringtonine production by endophytic fungus isolated from Cephalotaxus hainanensis Li.

Homoharringtonine (HHT), a natural plant alkaloid derived from Cephalotaxus, has demonstrated to have a broad antitumor activity and efficacy in treating human chronic myeloid leukemia. An alternative source is required to substitute for the slow-growing and scarce Cephalotaxus to meet the increasing demand of the drug market. The objective of this study was to screen HHT-producing endophytic fungi from Cephalotaxus hainanensis Li. By screening 213 fungal isolates obtained from the bark parts of Cephalotaxus hainanensis Li, one isolate was found to be capable of biosynthesizing HHT. The fungus was identified as Alternaria tenuissima by morphological characteristics and internal transcribed spacer (ITS) sequence analysis and was named as CH1307. HHT obtained from CH1307 was analyzed through the HPLC and LC-MS/MS and NMR spectroscopy. The extract of the fermentation broth of CH1307 showed antiproliferative activities against K562 (chronic myelocytic leukemia), NB4 (acute promyelocytic leukemia), and HL-60 (promyelocytic leukemia) human cancer cell lines with IC50 values of 67.25 ± 4.26, 65.02 ± 4.75, and 99.23 ± 4.26 µg/mL, respectively. The findings suggest that HHT-producing endophytic fungus, Alternaria tenuissima CH1307 might provide a promising source for the research and application of HHT.

A new furan derivative from an endophytic Aspergillus flavus of Cephalotaxus fortunei.

A new furan derivative named 5-acetoxymethylfuran-3-carboxylic acid (2), together with a known furan compound, 5-hydroxymethylfuran-3-carboxylic acid (1), were isolated from the fermentation of Aspergillus flavus, endophytic fungi in Cephalotaxus fortunei. The structures of 1 and 2 were elucidated by NMR, IR, UV and MS data, as well as compared with literature data. The compounds 1 and 2 exhibited potent antibacterial activity against Staphylococcus aureus with MIC values of 31.3 and 15.6 µg/mL, respectively. The compound 2 showed moderate antioxidant activity.

Diversity and antimicrobial activity of endophytic fungi isolated from Cephalotaxus hainanensis Li, a well-known medicinal plant in China.

UNLABELLED: About 1051 endophytic fungi were isolated from leaves, branches, barks and stems of Cephalotaxus hainanensis Li from four sites in Hainan, China. The fungi were identified as 21 genera by morphology and ITS sequences. One dominant species was Phomopsis quercella in Hainan Tropical Botanical Garden and Bawangling Nature Reserve, with relative frequency of 42·06 and 34·88% respectively. Another dominant species was Colletotrichum boninense in Wuzhishan and Jianfengling Nature Reserves, with relative frequency of 36·84 and 46·97% respectively. Among the selected 21 endophytic fungi, 17 strains (80·95%) had activity against at least one pathogenic bacteria, and 14 strains (66·67%) exhibited activity against at least one fungal pathogens. Neonectria macroconidialis showed strong inhibition against Staphylococcus aureus (inhibition zone being 20 mm), Bacillus subtilis (14 mm) and Streptococcus agalactiae (28 mm). Xylaria sp. showed strong inhibition against Escherichia coli (20 mm), Rhizoctonia solani (20 mm) and Sclerotinia sclerotiorum (17 mm). Verticillium bulbillosum showed great activity against Strep. agalactiae (32 mm) and Fusarium oxysporum (22 mm). These endophytic fungi showed potentials in medicine development. SIGNIFICANCE AND IMPACT OF THE STUDY: Endophytic fungi from medicinal plants are an important source of novel and viable drugs. Cephalotaxus hainanensis Li is well known for leukaemia treatment and its endophytic fungi were isolated to investigate the diversity and antimicrobial activity. It was found that Ce. hainanensis Li had rich endophytic fungi, and some fungi showed strong antimicrobial activity against certain pathogens. These fungi can be used in medicine development.

The fungal leaf endophyte Paraconiothyrium variabile specifically metabolizes the host-plant metabolome for its own benefit.

Fungal endophytes live inside plant tissues and some have been found to provide benefits to their host. Nevertheless, their ecological impact is not adequately understood. Considering the fact that endophytes are continuously interacting with their hosts, it is conceivable that both partners have substantial influence on each other's metabolic processes. In this context, we have investigated the action of the endophytic fungus Paraconiothyrium variabile, isolated from the leaves of Cephalotaxus harringtonia, on the secondary metabolome of the host-plant. The alteration of the leaf compounds by the fungus was monitored through metabolomic approaches followed by structural characterization of the altered products. Out of more than a thousand molecules present in the crude extract of the plant leaf, we have observed a specific biotransformation of glycosylated flavonoids by the endophyte. In all cases it led to the production of the corresponding aglycone via deglycosylation. The deglycosylated flavonoids turned out to display significant beneficial effects on the hyphal growth of germinated spores. Our finding, along with the known allelopathic role of flavonoids, illustrates the chemical cooperation underlying the mutualistic relationship between the plant and the endophyte.

Geographic locality greatly influences fungal endophyte communities in Cephalotaxus harringtonia.

Although endophytes of conifers have been extensively studied, few data are available on Cephalotaxaceae. We examined foliar and stem endophytes of Cephalotaxus harringtonia, within its natural range in Japan and outside its natural range in France to study the effect of geography on endophyte community composition. In Japan, rapidly growing endophytes were dominant and may have masked the real diversity, in comparison to France where most endophytes were growing slowly. Analyses of ITS rDNA revealed 104 different Blast Groups among 554 isolates. Almost no overlap between endophyte assemblages of C. harringtonia from the two countries was observed. It seems that Japanese C. harringtonia trees, which should be well adapted to their native site, would host a specific, endemic endophyte community, while trees that have been introduced recently to a foreign site, in France, should have captured existing cosmopolitan and more generalist taxa. In Japan the majority of xylariaceous taxa, which dominated the communities, were unknown and, although closely related to Asian taxa, may be new to science. Dothideomycetes were more prevalent in France. Locally, urban environment, particularly in Japan, may have introduced some perturbations in the native endophyte community of C. harringtonia, with an abundance of generalist fungi such as Nigrospora and Colletotrichum.

Chemical communication between the endophytic fungus Paraconiothyrium variabile and the phytopathogen Fusarium oxysporum.

Paraconiothyrium variabile, one of the specific endophytic fungi isolated from the host plant Cephalotaxus harringtonia, possesses the faculty to inhibit the growth of common phytopathogens, thus suggesting a role in its host protection. A strong antagonism between the endophyte P. variabile and Fusarium oxysporum was observed and studied using optic and electronic microscopies. A disorganization of the mycelium of F. oxysporum was thus noticed. Interestingly, the biological effect of the main secondary metabolites isolated from P. variabile against F. oxysporum did not account for this strong antagonism. However, a metabolomic approach of pure fungal strains and confrontation zones using the data analysis tool XCMS were analyzed and pointed out a competition-induced metabolite production by the endophyte in the presence of the phytopathogen. Subsequent MS/MS fragmentations permitted to identify one of the induced metabolites as 13-oxo-9,11-octadecadienoic acid and highlighted a negative modulation of the biosynthesis of beauvericin, one of the most potent mycotoxin of F. oxysporum, during the competition with the endophyte.

Guaiane sesquiterpenes from Biscogniauxia nummularia featuring potent antigerminative activity.

Xylaranone, a previously unreported guaiane sesquiterpene along with the known terpenoid xylaranol B and the two mellein derivatives 3,5-dimethyl-8-methoxy-3,4-dihydroisocoumarin and 3,5-dimethyl-8-hydroxy-3,4-dihydroisocoumarin were isolated from Biscogniauxia nummularia. Pogostol was also isolated from this fungus, and in light of our spectroscopic data, its structure was revised and corrected. This fungus, which was isolated as an endophyte from the plum yew Cephalotaxus harringtonia, is also suspected of being a pathogen. Interestingly, we report here the potent antigerminative activity of xylaranone and xylaranol B against seeds of Raphanus sativus at concentrations comparable to glyphosate, a commonly used herbicide. This effect suggests a role for these metabolites in the latent fungal pathogenesis of B. nummularia.

Aromatic compounds from endophytic fungus Colletotrichum sp. L10 of Cephalotaxus hainanensis Li.

Six aromatic compounds were isolated from the endophytic fungus Colletotrichum sp. of Cephalotaxus hainanensis Li [Cephalotaxus mannii Hook. f.]. Their structures were determined on the basis of chemical and spectroscopic methods. The compound 2 was the enantiomer of compound 1. The compound 4 was the epimeride of the compound 3. The compounds 1, 2, 4 and 5 were evaluated for cytostatic activity against HL-60 and PC-3 cells.

Two new compounds from the endophytic fungus Colletotrichum sp. L10 of Cephalotaxus hainanensis.

Two new compounds, 3-(4-methoxy-3-methyl-2-oxo-2H-pyran-6-yl)butyl pyroglutamate (1) and 2,2'-(1,1'-methylenebis(1H-indole-3,1-diyl))diethanol (2), were isolated from the endophytic fungus of Cephalotaxus hainanensis. Their structures were determined by means of chemical and spectroscopic analysis.

Sesquiterpenoids from Trichoderma atroviride, an endophytic fungus in Cephalotaxus fortunei.

Two new sesquiterpenoids, identified as (rel 1S, 3R, 4R, 7R)-3-[5-hydroxy-4-methylpent-3-enyl]-1, 3, 7-trimethyl-2-oxabicyclo [2, 2, 1] heptane (1) and (rel 1S, 3R, 4R, 7R)-3-[3, 4-dihydroxy-4-methylpentyl]-1, 3, 7-trimethyl-2-oxabicyclo [2, 2, 1] heptane (2), were isolated from cultures of Trichoderma atroviride (strain no. S361), an endophytic fungal strain residing in the bark of Cephalotaxus fortunei. The structures of compounds 1 and 2 were elucidated by detailed spectroscopic analyses on the basis of NMR, IR, and MS data. Both compounds 1 and 2 were potent inhibitors on NO production in LPS-stimulated RAW264.7 cells, with IC50 values of 15.3 and 9.1µM, respectively.

Two new sesquiterpenes from endophytic fungus S49 of Cephalotaxus hainanensis.

Two new sesquiterpenes, 10,11,12-guaianetriol (1) and 1,10,11,12-guaianetetrol (2), were isolated from endophytic fungus S49 of Cephalotaxus hainanensis Li. Their structures were determined based on HR-ESI-MS and spectroscopic techniques (1D and 2D NMR).

Actinopolymorpha cephalotaxi sp. nov., a novel actinomycete isolated from rhizosphere soil of the plant Cephalotaxus fortunei.

An actinomycete, strain I06-2230(T), was isolated from rhizosphere soil of the plant Cephalotaxus fortunei, collected from Yunnan province, south China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate belongs to the genus Actinopolymorpha. Cells grew on agar surfaces, with no penetration even after prolonged cultivation. Aerial hyphae were absent. Cells were irregularly shaped and remained attached as chains or aggregates. Chemotaxonomic data, which showed ll-diaminopimelic acid in the cell wall, glucose as the whole-cell sugar, type PI phospholipids and MK-9(H4) as the predominant menaquinone, supported the affiliation of strain I06-2230(T) to the genus Actinopolymorpha. The major fatty acids were iso-C(15 : 0), iso-C(16 : 0) and iso-C(16 : 1) H. The genomic DNA G+C content was 69.3 mol%. DNA-DNA hybridization data, in combination with chemotaxonomic, physiological and biochemical data, demonstrated that strain I06-2230(T) should be classified as representing a novel species of the genus Actinopolymorpha. The name Actinopolymorpha cephalotaxi sp. nov. is proposed, with strain I06-2230(T) (=DSM 45117(T)=CCM 7466(T)=KCTC 19293(T)) as the type strain.

A new 5-acyl-2-methylpyrrole from the endophytic fungus S20 of Cephalotaxus hainanensis.

A new 5-acyl-2-methylpyrrole, isolated from the endophytic fungus S20 of Cephalotaxus hainanensis, was elucidated as 1-(5-methyl-1H-pyrrol-2-yl)-2-((2S*,3R*)-3-((E)-prop-1-enyl)oxiran-2-yl)ethanone (1) on the basis of spectroscopic evidence, including 1D- and 2D-NMR (HMQC, 1H-1H COSY, HMBC and ROESY) and MS analysis. Compound 1 showed inhibitory effects on Staphylococcus aureus and methicillin-resistant S. aureus by the filter paper disc agar diffusion method.

Three new compounds from endophytic fungus L10 of Cephalotaxus hainanensis.

Three new compounds, 4-hydroxyphenethyl-2'-hydroxypropanoate (1), 6-(1',2'-dimethyloxiran-1'-yl)-4-methoxy-3-methyl-2H-pyran-2-one (2), 6-(1-hydroxyethyl)-4-methoxy-3-methyl-2H-pyran-2-one (3), along with the two known compounds, nectriapyrone (4) and wermopyrone (5), have been isolated from the endophytic fungus of Cephalotaxus hainanensis. Their structures were determined on the basis of chemical and spectroscopic methods.

Metabolites from endophytic fungus S20 of Cephalotaxus hainanensis.

Three new C-methylated acetogenins, (2E,6Z)-9,10-dihydroxy-4-hydroxymethyl-2,6-decadiene (1), (2E,6Z)-8,9,10-trihydroxy-4-hydroxymethyl-2,6-decadiene (2), and (2E,6Z)-9-hydroxy-4-hydroxymethyl-2,6-nonadiene (3), together with two known compounds, p-hydroxybenzyl alcohol (4) and indolyl-3-carboxylic acid (5), were isolated from endophytic fungus S20 of Cephalotaxus hainanensis Li. Their structures were determined based on HR-ESI-MS and spectroscopic techniques (IR, UV, 1D, and 2D NMR). Compound 5 showed inhibitory effects on Staphylococcus aureus and methicillin-resistant S. aureus by the filter paper disc agar diffusion method.