Mechanisms of Epichloë bromicola to Promote Plant Growth and Its Potential Application for Coix lacryma-jobi L. Cultivation.

Endophytic fungi play important roles in regulating plant growth and development and usually used as a promising strategy to enhance the biosynthesis of host valuable secondary metabolite, but the underlying growth-promoting mechanisms are only partly understood. In this study, the wild-type Arabidopsis thaliana seedlings co-cultured with fungal endophyte Epichloë bromicola showed auxin (IAA)-stimulated phenotypes, and the growth-promoting effects caused by E. bromicola were further verified by the experiments of spatially separated co-culture and fungal extract treatment. IAA was detected and identified in the extract of E. bromicola culture by LC-HRMS/MS, whereas 2,3-butanediol was confirmed to be the predominant volatile active compound in the diethyl ether and ethyl acetate extracts by GC-MS. Further study observed that IAA-related genes including synthesis key enzyme genes (CYP79B2, CYP79B3, NIT1, TAA1 and YUCCA1) and controlling polar transport genes (AUX1, BIG, EIR1, AXR3 and ARF1), were highly expressed at different periods after E. bromicola inoculation. More importantly, the introduction of fungal endophyte E. bromicola could effectively promote the growth and accumulation of coixol in Coix under soil conditions. Our study showed that endophytic fungus E. bromicola might be considered as a potential inoculant for improving medicinal plant growth.

The regulatory mechanism of fungal elicitor-induced secondary metabolite biosynthesis in medical plants.

A wide range of external stress stimuli trigger plant cells to undergo complex network of reactions that ultimately lead to the synthesis and accumulation of secondary metabolites. Accumulation of such metabolites often occurs in plants subjected to stresses including various elicitors or signal molecules. Throughout evolution, endophytic fungi, an important constituent in the environment of medicinal plants, have known to form long-term stable and mutually beneficial symbiosis with medicinal plants. The endophytic fungal elicitor can rapidly and specifically induce the expression of specific genes in medicinal plants which can result in the activation of a series of specific secondary metabolic pathways resulting in the significant accumulation of active ingredients. Here we summarize the progress made on the mechanisms of fungal elicitor including elicitor signal recognition, signal transduction, gene expression and activation of the key enzymes and its application. This review provides guidance on studies which may be conducted to promote the efficient synthesis and accumulation of active ingredients by the endogenous fungal elicitor in medicinal plant cells, and provides new ideas and methods of studying the regulation of secondary metabolism in medicinal plants.

Medicinal plant cell suspension cultures: pharmaceutical applications and high-yielding strategies for the desired secondary metabolites.

The development of plant tissue (including organ and cell) cultures for the production of secondary metabolites has been underway for more than three decades. Plant cell cultures with the production of high-value secondary metabolites are promising potential alternative sources for the production of pharmaceutical agents of industrial importance. Medicinal plant cell suspension cultures (MPCSC), which are characterized with the feature of fermentation with plant cell totipotency, could be a promising alternative "chemical factory". However, low productivity becomes an inevitable obstacle limiting further commercialization of MPCSC and the application to large-scale production is still limited to a few processes. This review generalizes and analyzes the recent progress of this bioproduction platform for the provision of medicinal chemicals and outlines a range of trials taken or underway to increase product yields from MPCSC. The scale-up of MPCSC, which could lead to an unlimited supply of pharmaceuticals, including strategies to overcome and solution of the associated challenges, is discussed.

Phytochemical and Pharmacological Profiles of Three Fagopyrum Buckwheats.

The genus Fagopyrum (Polygonaceae), currently comprising 15 species of plants, includes three important buckwheat species: Fagopyrum esculentum (F. esculentum) Moench. (common buckwheat), Fagopyrum tataricum (F. tataricum) (L.) Gaertn. (tartary buckwheat) and Fagopyrum dibotrys (F. dibotrys) (D. Don) Hara. (perennial buckwheat), which have been well explored due to their long tradition of both edible and medicinal use. This review aimed to present an up-to-date and comprehensive analysis of the phytochemistry and pharmacology of the three Fagopyrum buckwheats. In addition, the scope for future research was also discussed. All available references included in this paper were compiled from major databases, such as MEDLINE, Pubmed, Scholar, Elsevier, Springer, Wiley and CNKI. A total of 106 compounds isolated from three Fagopyrum buckwheats can be mainly divided into six classes: flavonoids, phenolics, fagopyritols, triterpenoids, steroids and fatty acids. Flavonoids and phenolic compounds were considered to be the major active components. Considerable pharmacological experiments both in vitro and in vivo have validated that Fagopyrum buckwheats possess antitumor, anti-oxidant, anti-inflammatory, hepatoprotective, anti-diabetic activities, etc. All reported data lead us to conclude that Fagopyrum buckwheats have convincing medicinal potential. However, further research is needed to explore its bioactive constituents, the relationship to their structural activities and the molecular mechanisms of action.

Matrine Exerts a Strong Anti-Arthritic Effect on Type II Collagen-Induced Arthritis in Rats by Inhibiting Inflammatory Responses.

To investigate anti-arthritic effects of matrine isolated from the roots of S. flavescens on type II collagen-induced arthritis (CIA) in rats and to explore its related potential mechanisms, CIA rats were established and administered with matrine (20, 40 or 80 mg/kg/days, for 30 days). Subsequently, blood was collected to determine serum levels of TNF-α, IL-1ß, IL-6, IL-8, IL-17A, IL-10, MMP-2, MMP-3 and MMP-9, and hind paws and knee joints were collected for histopathological examination. Furthermore, indices of the thymus and spleen were determined, and synovial tissues were collected to determine the protein expressions of p-IκB, IκB, Cox-2 and iNOS. Our results indicated that matrine significantly suppressed inflammatory reactions and synovial tissue destruction. Matrine inhibited paw swelling, arthritis indices and weight loss in CIA rats. Additionally, matrine decreased the levels of TNF-α, IL-1ß, IL-6, IL-8, IL-17A, MMP-2, MMP-3 and MMP-9. Matrine also down-regulated expressions of p-IκB, Cox-2, and iNOS but up-regulated IκB in synovial tissues in CIA rats. The results suggested matrine possesses an anti-arthritic effect in CIA rats via inhibiting the release of pro-inflammatory cytokines and proteins that promote the NF-κB pathway.

Phytochemical and Pharmacological Profile of Vitex negundo.

The article aims to review all the chemical constituents and pharmacological properties of Vitex negundo L. (Verbenaceae) (VN). VN is an important medicinal plant used as reputed herbal medicine with versatile pharmacological activities in China, India and Japan. A total of 104 referred articles about VN were compiled from major databases and academic publishers, such as MEDLINE, Pubmed, Scholar, Elsevier, Springer, Wiley and CNKI. As a result, a total of 120 compounds isolated from VN can be divided mainly into four classes: flavonoids, lignans, terpenoids and steroids. The crude extracts and purified compounds of VN exhibited promising bioactivities, including anti-nociceptive, antiinflammatory, anti-tumor, anti-oxidant, insecticidal, antimicrobial, anti-androgenic, anti-osteoporotic, anti-cataract, hepatoprotective and anti-hyperglycemic activity. All the reported data lead us to conclude that VN has convincing medicinal potential. However, further researches are needed to explore its bioactive constituents, the structure-activity relationship and their molecular mechanisms of action.

Antiinflammatory effects and chemical constituents of Veronicastrum axillare.

Our study aims to ascertain the antiinflammatory activity of Veronicastrum axillare and characterize the bioactive constituents. Antiinflammatory activity of the total extract and different fractions from V. axillare was investigated by employing the xylene-induced mouse ear edema model. As a result, the ethyl acetate (EtOAc) fraction showed the highest antiinflammatory activity in vivo. From the EtOAc fraction and the inactive dichloromethane fraction, a total of five new compounds, axillasides A-C and axillactones A and B, together with four known compounds, procumboside A, buergeriside C1 , indole-3-carboxylic acid and apigenin, were isolated and identified. Their structures were elucidated on the basis of spectroscopic analysis and by comparison of their nuclear magnetic resonance data with those reported in the literature. Procumboside A, a major constituent in EtOAc fraction, showed significant antiinflammatory activity in vivo. Further studies revealed that procumboside A was a potent COX-2 inhibitor, significantly reducing the COX-2 protein level in lipopolysaccharide-stimulated RAW 264.7 macrophages.

Monoterpenoids from the whole herb of Veronicastrum axillare.

CONTEXT: Veronicastrum axillare (Sieb. et Zucc.) Yamazaki (Scrophulariaceae) embraces varieties of bioactivities such as anti-inflammatory, anti-pyresis and detoxification activity, while little is known of the phytochemical components of this medicinal plant. OBJECTIVE: To isolate and identify bioactive constituents from the whole herb of V. axillare. MATERIALS AND METHODS: Ethanol extract of the whole herb of V. axillare was subjected to successive column chromatography. Chemical structures of the compounds were elucidated by detailed spectroscopic analyses on the basis of NMR, IR and HR-MS data. RESULTS: A new monoterpenoid, axillacetal A (1) and a known analogue, tarumal (2), were isolated from the whole herb of V. axillare. The structure of tarumal (2) was also revised according to our NMR data. DISCUSSION AND CONCLUSION: This is the first report on the isolation and authentication of novel chemical constituents from V. axillare.

The Natural Products Discovery Center: Release of the First 8490 Sequenced Strains for Exploring Actinobacteria Biosynthetic Diversity.

Actinobacteria, the bacterial phylum most renowned for natural product discovery, has been established as a valuable source for drug discovery and biotechnology but is underrepresented within accessible genome and strain collections. Herein, we introduce the Natural Products Discovery Center (NPDC), featuring 122,449 strains assembled over eight decades, the genomes of the first 8490 NPDC strains (7142 Actinobacteria), and the online NPDC Portal making both strains and genomes publicly available. A comparative survey of RefSeq and NPDC Actinobacteria highlights the taxonomic and biosynthetic diversity within the NPDC collection, including three new genera, hundreds of new species, and ~7000 new gene cluster families. Selected examples demonstrate how the NPDC Portal's strain metadata, genomes, and biosynthetic gene clusters can be leveraged using genome mining approaches. Our findings underscore the ongoing significance of Actinobacteria in natural product discovery, and the NPDC serves as an unparalleled resource for both Actinobacteria strains and genomes.

Labdane-type diterpenoids from the fruits of Vitex trifolia.

Seven new labdane-type diterpenoids, vitextrifolins A-G (1-7), along with eight previously reported analogues, were isolated from the fruits of Vitex trifolia. The structures of 1-7 were elucidated by spectroscopic data interpretation. The isolates were evaluated for their cytotoxicity against four human cancer cell lines (A549, HCT116, HL-60, and ZR-75-30), but all were inactive (IC(50) < 5 µg/mL).

Cytotoxic metabolites from Perenniporia tephropora, an endophytic fungus from Taxus chinensis var. mairei.

Based on bioactivity-oriented isolation, the EtOAc extract of a culture broth of the endophytic fungus Perenniporia tephropora Z41 from Taxus chinensis var. mairei, with strong anti-Pyricularia oryzae activity, afforded a new sesquiterpenoid, perenniporin A (1), together with three known compounds, ergosterol (2), rel-(+)-(2aR,5R,5aR,8S,8aS,8bR)-decahydro-2,2,5,8-tetramethyl-2H-naphtho[1,8-bc]genfuran-5-ol (3), and albicanol (4). Their structures were elucidated by means of spectroscopic methods. All the isolated compounds and the EtOAc extract of P. tephropora Z41 (EPT) were evaluated for their cytotoxic activity against three human cancer cell lines (HeLa, SMMC-7721, and PANC-1). EPT demonstrated significant cytotoxicity with IC(50) values ranging from 2 to 15 µg/mL. Compound 2 was the most cytotoxic constituent against the tested cell lines with IC(50) values of 1.16, 11.63, and 11.80 µg/mL, respectively, while compounds 1, 3, and 4 exhibited moderate cytotoxicity with IC(50) values ranging from 6 to 58 µg/mL. We conclude that the endophytic fungus P. tephropora is a promising source of novel and cytotoxic metabolites.

Cytotoxic metabolites from the cultures of endophytic fungi from Panax ginseng.

Two strains of endophytic fungi, Penicillium melinii Yuan-25 and Penicillium janthinellum Yuan-27, with strong anti-Pyricularia oryzae activity, were obtained from the roots of Panax ginseng. Based on bioactivity-oriented isolation, a new benzaldehyde derivative, ginsenocin (1), together with six known compounds, methyl 2,4-dihydroxy-3,5,6-trimethylbenzoate (2), 3,4,5-trimethyl-1,2-benzenediol (3), penicillic acid (4), mannitol (5), ergosterol (6), and ergosterol peroxide (7), were separated from the EtOAc extract of Yuan-25 culture, while brefeldin A (8) was isolated as the major constituent from the EtOAc extract of Yuan-27 culture. The chemical structures were determined based on spectroscopic methods. All the isolated compounds 1-8 were evaluated for their cytotoxicity against six human cancer cell lines. Brefeldin A (8) was the most cytotoxic constituent against all the tested cell lines with IC50 values <0.12 µg/ml, while ginsenocin (1) and penicillic acid (4) also exhibited potent cytotoxicity with IC50 values ranging from 0.49 to 7.46 µg/ml. Our results suggest that endophytic fungi isolated from P. ginseng are a promising natural source of potential anticancer agents.

Anoectochiluszhongshanensis (Orchidaceae), a new species from Guangxi, China.

A new species of Anoectochilus (Orchidaceae) from Guangxi, China, A.zhongshanensis, is described here, which was identified based on phylogenetic studies adopting combined plastid markers (rbcL-matK-trnL-F), morphological observation and chemical analysis. Molecular phylogenetic results support the systematic status of A.zhongshanensis as a new species in Anoectochilus genus. Morphologically, this new species is similar to A.zhejiangensis and A.malipoensis, but differs by its characteristic labellum and column, including the hastate or scalpel-shaped lobes of epichile, forward curved and pinnately divided cristate lobes at both sides of the mesochile and inverted triangle column wings. Furthermore, HPLC-ELSD analysis of these three species revealed the interesting chemotaxonomic difference that the principle and characteristic lactone glycoside in this new species was kinsenoside, rather than its diastereoisomer, goodyeroside A, a major glycoside in A.zhejiangensis and A.malipoensis.

Identification of a quinazoline alkaloid produced by Penicillium vinaceum, an endophytic fungus from Crocus sativus.

CONTEXT: Endophytic fungi are microorganisms living within the tissues of host plants, and have proven to be rich sources of biologically active secondary metabolites and therefore have attracted increasing attention in recent years. OBJECTIVE: To isolate and characterize bioactive constituents from the endophytic fungus cultures of Crocus sativus Linn. (Iridaceae). MATERIALS AND METHODS: Endophytes were isolated from the corm of C. sativus. Endophytic fungus cultures were subjected to repeated column chromatography. Chemical structure was elucidated based on extensive spectroscopic methods and X-ray diffraction analysis. Several pathogenic fungi isolates and tumor cell lines were employed to evaluate the antifungal and cytotoxic activities of the isolated compound. RESULTS: An isolate of Penicillium vinaceum (strain no. X17) was obtained from the corm of C. sativus. Chemical investigations of the endophyte culture broth afforded an unique quinazoline alkaloid (1), identified as (-)-(1R,4R)-1,4-(2,3)-indolmethane-1-methyl-2,4-dihydro-1H-pyrazino-[2,1-b]-quinazoline-3,6-dione, which showed cytotoxic (IC(50) range 40.55-76.83 µg/mL) and antifungal (MIC(80) range 16-64 µg/mL) activities. DISCUSSION AND CONCLUSIONS: Endophytes in C. sativus can be a rich source of novel bioactive compounds, which prompts us to expand the medicinal resource of this valuable plant in another way. Compound 1 exhibited potential cytotoxic and antifungal activities and may be considered a lead compound for promising antifungal and anticariogenic agent.

A new labdane diterpene from Vitex negundo.

CONTEXT: Vitex negundo Linn. (Verbenaceae) seeds are pepper substitute and occasionally used as a condiment for edible purposes. The seeds also find use for analgesia, sedation, rheumatism and joint inflammation in folk medicine. OBJECTIVE: To isolate and characterize bioactive constituents from V. negundo seeds. MATERIALS AND METHODS: The ethanol extract of V. negundo seeds was subjected to repeated column chromatography. Chemical structures were elucidated by detailed spectroscopic analyses on the basis of NMR, IR, and MS data. Several pathogenic fungi isolates were employed to evaluate the antifungal activity of the isolated compound. RESULTS: Chemical investigations of the seed extract afforded a new labdane diterpenoid, named negundol (1a + 1b), as an inseparable mixture of two diastereoisomers in a 5:4 ratio. Their structures were identified as (rel 3S, 5S, 8R, 9R, 10S, 13S, 16S)-3-acetoxy-9, 13-epoxy-16-hydroxy-labda-15, 16-olide (1a), and (rel 3S, 5S, 8R, 9R, 10S, 13S, 16R)-3-acetoxy-9, 13-epoxy-16-hydroxy-labda-15, 16-olide (1b). Compound 1 was active as an antifungal agent with MIC80 values in the range of 16-64 µg/mL. DISCUSSION AND CONCLUSION: The presence of compound 1 in V. negundo is of chemotaxonomic significance, since plants under the genus Vitex are chemically characterized with labdane diterpenoids. Compound 1 exhibited potential antifungal activity and may be considered a lead compound for promising antifungal agent.

Antifatigue activity of the liposoluble fraction from Acanthopanax senticosus.

The crude extract of Acanthopanax senticosus (AS) has been used extensively in Russia, China, Korea and Japan as an adaptogenic agent to fight against stress and fatigue. However, whether the liposoluble fraction possesses antifatigue activity or not is still unclear. A liposoluble fraction was administered orally to mice for 9 days. The swimming time to exhaustion was longer in the treatment groups (22.2 ± 3.3, 25.5 ± 4.8 min) than in the control group (13.7 ± 1.2 min, p < 0.05). The plasma TG (triglyceride) and BUN (blood urea nitrogen) levels in the high dose (500 mg/kg) groups were decreased significantly compared with the control group. Plasma lactate dehydrogenase (LDH) was lower in the treatment groups than in the control group. Chemical analysis from GC/MS revealed that the main components of the liposoluble fraction of AS were saturated fatty acid (12.98%), unsaturated fatty acid (33.13%), unsaturated alcohol (27.46%) and diolefine (15.76%). In conclusion, the liposoluble fraction enhanced the forced swimming capacity of mice by decreasing muscle damage, effectively preventing the increase in BUN concentration and increasing fat utilization. It is proposed that the antioxidant effect may be one of the antifatigue mechanisms of the liposoluble fraction of AS.

Chemical constituents and bioactivities of the liposoluble fraction from different medicinal parts of Crocus sativus.

CONTEXT: Crocus sativus Linn. (Iridaceae), commonly known as saffron, becomes more and more popular due to its versatile biological and medicinal properties. At present, studies mainly focus on the traditional medicinal part, the saffron stigma, with less attention to the other parts of saffron, such as the perianth, the stamen, and the corm, which are high yield compared to the stigma and also possess various pharmacological effects. OBJECTIVE: To determine the chemical compositions, antifungal, cytotoxic, and antioxidant activities of the ether fractions from the stamen, perianth, and stigma of saffron. MATERIALS AND METHODS: The chemical constituents of the ether fractions from different parts of saffron were investigated by gas chromatography/mass spectrometry. Several pathogenic fungi isolates and tumor cell lines were employed to evaluate the antifungal and cytotoxic activities of these three ether fractions. 1,1-Diphenyl-2-picrylhydrazyl assay was used to determine the free radical-scavenging activity. RESULTS: The ether fractions composition of the three C. sativus parts are different from each other, but lauric acid, hexadecanoic acid, 4-hydroxydihydro-2(3H)-furanone, and stigmasterol were the common constituents shared by all the three fractions. The stamen ether fraction displayed the strongest antifungal and cytotoxic activities, whereas both of the saffron stamen and perianth ether fractions exhibited significant antioxidant activities. DISCUSSION AND CONCLUSION: These findings demonstrate that the saffron stamen and perianth possess significant antifungal, cytotoxic, and antioxidant activities as well as the stigma, though not to the same extent, prompting us to expand the medicinal resource and make best use of this valuable plant.

Corrigendum to "Quantitative determination of multi-class bioactive constituents for quality assessment of ten Anoectochilus, four Goodyera and one Ludisia species in China" [Chinese Herbal Medicines 12 (2020) 430-439].

[This corrects the article DOI: 10.1016/j.chmed.2020.07.002.].

PtmC Catalyzes the Final Step of Thioplatensimycin, Thioplatencin, and Thioplatensilin Biosynthesis and Expands the Scope of Arylamine N-Acetyltransferases.

The members of the arylamine N-acetyltransferase (NAT) family of enzymes are important for their many roles in xenobiotic detoxification in bacteria and humans. However, very little is known about their roles outside of detoxification or their specificities for acyl donors larger than acetyl-CoA. Herein, we report the detailed study of PtmC, an unusual NAT homologue encoded in the biosynthetic gene cluster for thioplatensimycin, thioplatencin, and a newly reported scaffold, thioplatensilin, thioacid-containing diterpenoids and highly potent inhibitors of bacterial and mammalian fatty acid synthases. As the final enzyme of the pathway, PtmC is responsible for the selection of a thioacid arylamine over its cognate carboxylic acid and coupling to at least three large, 17-carbon ketolide-CoA substrates. Therefore, this study uses a combined approach of enzymology and molecular modeling to reveal how PtmC has evolved from the canonical NAT scaffold into a key part of a natural combinatorial biosynthetic pathway. Additionally, genome mining has revealed the presence of other related NATs located within natural product biosynthetic gene clusters. Thus, findings from this study are expected to expand our knowledge of how enzymes evolve for expanded substrate diversity and enable additional predictions about the activities of NATs involved in natural product biosynthesis and xenobiotic detoxification.

Anti-inflammatory diterpenes from the seeds of Vitex negundo.

Phytochemical investigation of a dichloromethane-soluble extract of Vitexnegundo seeds led to the isolation of five labdane diterpenes, negundoins A-E (1-5), a 9,10-seco-abietane diterpene, negundoin F (6), a sandaracopimara-7,15-diene diterpene, negundoin G (7), and two known diterpene derivatives (8, 9). Their chemical structures were elucidated by detailed spectroscopic analyses on the basis of NMR, IR, and MS data. The anti-inflammatory effects of metabolites 1-7 were also evaluated in vitro. Compounds 3 and 5 were among the most potent inhibitors on nitric oxide production by LPS-stimulated RAW 264.7 macrophages, with IC(50) values of 0.12 and 0.23 microM, respectively. Further studies revealed that compounds 3 and 5 (5 microM) significantly reduced the levels of the iNOS protein to 0.40+/-0.13% and 41.02+/-6.02%, respectively, and COX-2 protein to 2.06+/-0.53% and 26.40+/-7.43%, respectively.