Metabolites with antioxidant and α-glucosidase inhibitory activities produced by the endophytic fungi Aspergillus niger from Pachysandra terminalis.

One new compound and 13 known compounds were isolated from Aspergillus niger, a plant endophytic fungus of Pachysandra terminalis collected from Qinling Mountains, Xi'an, China. The structure of new compound 1 was classically determined by extensive spectroscopic analysis. Compounds 5, 6, 8, and 14 were first reported from Aspergillus, while compound 2 was isolated from A. niger for the first time. All isolated compounds were further evaluated for their antioxidant and α-glucosidase inhibitory activities. Compounds 2 and 3 exhibited significant antioxidant activities with IC50 values of 31.64 µm and 24.32 µm, respectively, similar to the positive control ascorbic acid. Additionally, compound 1 displayed remarkable inhibitory activity against α-glucosidase with an IC50 value of 96.25 µm, which was 3.4-fold more potent than that of the positive control acarbose. Compound 1 has great potential for development as a new lead compound owing to its simple structure and remarkable biological activity.

The Alkaloid-Enriched Fraction of Pachysandra terminalis (Buxaceae) Shows Prominent Activity against Trypanosoma brucei rhodesiense.

In the course of our studies on antiprotozoal natural products and following our recent discovery that certain aminosteroids and aminocycloartanoid compounds from Holarrhena africana A. DC. (Apocynaceae) and Buxus sempervirens L. (Buxaceae), respectively, are strong and selective antitrypanosomal agents, we have extended these studies to another plant, related to the latter-namely, Pachysandra terminalis Sieb. and Zucc. (Buxaceae). This species is known to contain aminosteroids similar to those of Holarrhena and structurally related to the aminocycloartanoids of Buxus. The dicholoromethane extract obtained from aerial parts of P. terminalis and, in particular, its alkaloid fraction obtained by acid-base partitioning showed prominent activity against Trypanosoma brucei rhodesiense (Tbr). Activity-guided fractionation along with extended UHPLC-(+)ESI QTOF MS analyses coupled with partial least squares (PLS) regression modelling relating the analytical profiles of various fractions with their bioactivity against Tbr highlighted eighteen constituents likely responsible for the antitrypanosomal activity. Detailed analysis of their (+)ESI mass spectral fragmentation allowed identification of four known constituents of P. terminalis as well as structural characterization of ten further amino-/amidosteroids not previously reported from this plant.

Two new pregnane alkaloids from Pachysandra terminalis Sieb. et Zucc.

Two new pregnane alkaloids, (20S)-20α-cinnamoylamino-3ß-dimethylamino-5-en-pregnane (1) and (20S)-20α-cinnamoylamino-3ß-dimethylamino-pregnane (2), and four known alkaloids (+)-(20S)-20-(dimethylamino)-3-(3'R-isopropyl)-lactam-5α-pregn-2-en-4-one (3), axillaridine A (4), pachysamine M (5) and 20α-dimethylamino-16ß-hydroxy-3ß-senecioylamino-pregn-5-ene (6) were obtained from the whole herb of Pachysandra terminalis Sieb. et Zucc. Their structures were determined by various spectral techniques and computed electronic circular dichroism (ECD) data. Compounds 1-4 were tested for cytotoxicity against three human tumor cell lines and a human umbilical vein endothelial cell (HUVEC) line. Compound 4 exhibited moderate cytotoxicity against MCF-7, U251 and A549 cells with IC50 values of 15.01 ± 0.47 µM, 20.13 ± 1.34 µM and 20.04 ± 1.16 µM, respectively; compounds 1-3 showed weak cytotoxic activity against three tumor cells.

In Silico insights on enhancing thermostability and activity of a plant Fructosyltransferase from Pachysandra terminalis via introduction of disulfide bridges.

Drawbacks of industrially-used fructosyltransferases (FTs) such as low optimum temperature and low fructooligosaccharides (FOS) yield necessitates the search for engineered FTs that are highly thermostable and active. With the availability of the first plant FT crystal structure from Pachysandra terminalis (PDB ID: 3UGH), computer-aided protein engineering of plant FT is now feasible. To obtain insights on the effect of specific mutations i.e. disulfide bridge introduction, wild-type and mutant FTs were subjected to a 15 µs Martini Coarse-grained Molecular Dynamics (CGMD) simulations at 303 K and 334 K. We report here the five mutants, M31C-Q49C, L144C-S193C, P34C-W300C, S219C-L226C and V470C-S498C with enhanced thermostabilities and/or activities relative to the wild type. Interestingly, M31C-Q49C, which is located within the catalytic-carrying blade of the catalytic domain, has an activity enhancement at both temperatures. At 334 K, three mutations, L144C-S193C, P34C-W300C and V470C-S498C, achieved thermostability relative to the wild type. Intriguingly, both activity and stability enhancement exhibited only at 334 K can be achieved provided that the mutation is located either on the catalytic-carrying residue blade of the catalytic domain or on the non-catalytic domain. Our results suggest that V470C-S498C and L144C-S193C are promising mutants and that domain-specific approach may be exploited to customize enzyme properties.

Host responses and impact on the boxwood blight pathogen, Calonectria pseudonaviculata.

MAIN CONCLUSION: Boxwood leaves are more susceptible to Calonectria pseudonaviculata (Cps) and better suited for Cps reproduction than those of pachysandra and sweet box. Passages through a non-boxwood host may alter Cps ability to sporulate. Calonectria pseudonaviculata (Cps) infects boxwood and its two common companion plants-pachysandra and sweet box. This study investigated how boxwood, pachysandra, and sweet box respond to Cps isolates of different host origin. Detached leaves were inoculated with nine isolates, three from each host, and evaluated for colonization, infection rate, lesion size, and production of conidia and microsclerotia. Cps colonized boxwood leaf tissue within 12 h of inoculation, and 60 h ahead of pachysandra and sweet box. Cps also produced significantly larger lesions and more conidia on boxwood than on pachysandra and sweet box. Isolates originating from different host plants did not differ in all the components evaluated except for conidia production. Isolates from boxwood and sweet box produced significantly more conidia than those from pachysandra. Overall, boxwood leaves are more susceptible to the disease and are better suited for Cps reproduction than those of pachysandra and sweet box. Passages through a non-boxwood host may alter Cps ability to sporulate. These results advance the understanding of Cps biology and affirm the importance of taking pachysandra and sweet box into consideration in disease management planning.

The synthesis and anti-metastatic effects of optical isomers of ionone alkaloid 9-(N,N-dimethyl)-4,7-megastigmedien-3-one.

Ionone alkaloid 9-(N,N-dimethyl)-4,7-megastigmedien-3-one (compound 1) is a new anti-metastatic natural product. However, it was previously reported as optical isomers mixture. Herein, the optical isomers (6a-6d) of compound 1 were synthesized. The absolute configurations of 6a-6d were determined by ECD experiments and calculated spectra with time-dependent density functional theory (TDDFT). The anti-metastatic effects of the optical isomers were examined by transwell assay. These results revealed that compound 6a had potential anti-metastatic activity with an IC50 value of 0.512 ±â€¯0.093 µM.

A novel pregnane-type alkaloid from Pachysandra terminalis inhibits methicillin-resistant Staphylococcus aureus in vitro and in vivo.

A new kind of pregnane-type alkaloid, 20α-dimethylamino-3ß-senecioylamino-16ß-hydroxy-pregn-5-ene (K-6), was isolated from Pachysandra terminalis Sieb. et Zucc., and its antibacterial activity against MRSA and MRSE was evaluated. We found that K-6 showed antibacterial effects against MRSA and MRSE with minimum inhibitory concentration values (25 mg/L), but did not induce antibiotic resistance in bacteria easily. The administration of K-6 dose-dependently improved the animal survival rate of mice infected with MRSA, with survival rates of 36.34% and 66.67% in the low-dose and high-dose groups, respectively. The protective effects were associated with the reduction of the bacterial titers in the blood and with the morphological amelioration of infected tissues. Scanning and transmission electron microscopy analyses indicated that the cytoplasm shrink of bacterial cells led to noticeable gaps between the cell membrane and cell cytoplasm, and the severely damaged cell membrane resulted in leakage of intracellular content, which ultimately caused the lethal effect of K-6 on bacteria. These findings demonstrated that K-6 is a potential agent against MRSA and MRSE.

Liquid chromatography/mass spectrometry analysis of branched fructans produced in vitro with 13C-labeled substrates.

RATIONALE: Fructans are carbohydrates predominantly based on fructose which are generally considered to be soluble dietary fibers with health-promoting properties. It is known that the nutritional properties of fructans are affected by their structure. This study focused on structural determination of branched fructans, as the most important dietary fructans are branched graminan-type fructans. METHODS: Branched fructans were synthesized enzymatically by incubation of a heterologously expressed sucrose:fructan 6-fructosyltransferase (6-SFT) from Pachysandra terminalis with native or (13)C-labeled substrates. Liquid chromatography/mass spectrometry (LC/MS) was used for the structural identification of branched fructans. The MS(2) fragmentation of these compounds is described for the first time. Analytes were charged by electrospray ionization in negative mode and a quadrupole mass analyzer was used for MS(2) analysis. RESULTS: The MS(2) fragmentation patterns of branched and linear fructans were shown to differ and distinctive ion formation allowed differentiation between all branched fructan isomers formed. P. terminalis 6-SFT preferred extending the existing fructan branch rather than creating a new branch. CONCLUSIONS: The MS(2) fragmentation patterns described in the current paper now allow rapid screening of large sample sets for the presence of branched, graminan-type fructans. Furthermore, the data enables the characterization of fructan-metabolizing enzymes by identification of the fructan structures produced by in vitro reactions as described here for P. terminalis 6-SFT.

Synthesis and antimetastatic effects of E-salignone amide derivatives.

The preparation of novel E-salignone derivatives and their biological evaluation as potential antimetastatic agents is described. The E-salignone amide derivatives were prepared from epiandrosterone and androsterone, and characterized by analytical (1) H NMR, (13) C NMR, and mass spectrometry. The derivatives were evaluated for antimetastatic activity in MDA-MB-231 cells by using a transwell assay. Comparing with the positive control, LY294002, compounds 19b, 19d, and 19e exhibited significant inhibitory effects on the EGF-induced invasion of MB-MDA-231 cells. Moreover, compound 19b also had antimigration effects in wound-healing assay. Compound 19b may represent a novel antimetastatic agent for treating breast cancer.

Antitumor metastasis pregnane alkaloids from Pachysandra terminalis.

Three new pregnane alkaloids, named terminamines H-J (1-3), together with two known alkaloids (4 and 5), were isolated from the ethanol extract of Pachysandra terminalis. The structures of isolated compounds were elucidated by spectroscopic methods, including (1)H and (13)C NMR, 2D NMR, and HR-ESI-MS. Compounds 1, 4, and 5 revealed significant anti-metastasis activities. In addition, compound 1 inhibited the expression of p-PKCζ in MDA-MB-231 cells, and compound 4 inhibited the expressions of p-PKCζ in MDA-MB-231 and A549 cells.

[Chemical constituents from Pachysandra terminalis].

To study chemical constituents from Pachysandra terminalis. By repeated column chromatography, including silica gel, Toyopearl HW-40, and preparative HPLC, four new (14) and one known (5) compounds were isolated and purified. On the basis of spectral data analysis, the structure of isolated compounds were elucidated as follow: 2-methyl-3-methylenepentane-1, 2, 5-triol (1), 4-methyl-3-methylenepentane-1, 2, 5-triol (2), 4-methyl-3-methylenepentane-1, 2, 5-triol-5-O-beta-D-glucopyranoside (3), 4-methyl-3-methylenep- entane-1, 2, 5-triol-1-O-beta-D-glucopyranoside (4), (7S, 8R, 8' R)-(+)-lariciresinol-9-O-beta-D-glucopyrano-side (5). Compound 5 was isolated from this genus for the first time.

Chemical constituents from Pachysandra terminalis / 中国中药杂志

To study chemical constituents from Pachysandra terminalis. By repeated column chromatography, including silica gel, Toyopearl HW-40, and preparative HPLC, four new (14) and one known (5) compounds were isolated and purified. On the basis of spectral data analysis, the structure of isolated compounds were elucidated as follow: 2-methyl-3-methylenepentane-1, 2, 5-triol (1), 4-methyl-3-methylenepentane-1, 2, 5-triol (2), 4-methyl-3-methylenepentane-1, 2, 5-triol-5-O-beta-D-glucopyranoside (3), 4-methyl-3-methylenep- entane-1, 2, 5-triol-1-O-beta-D-glucopyranoside (4), (7S, 8R, 8' R)-(+)-lariciresinol-9-O-beta-D-glucopyrano-side (5). Compound 5 was isolated from this genus for the first time.

Alkaloids from Pachysandra terminalis inhibit breast cancer invasion and have potential for development as antimetastasis therapeutic agents.

The aim of the present study was to identify potentially useful natural compounds for the development of novel therapeutic agents to inhibit metastasis. A phytochemical investigation of Pachysandra terminalis resulted in the isolation of seven new pregnane alkaloids, terminamines A-G (1-7), and seven known alkaloids (8-14). The structures of 1-7 were elucidated by 1D- and 2D-NMR spectroscopic and mass spectrometric methods. Compounds 1-5 and 8-14 inhibited the migration of MB-MDA-231 breast cancer cells induced by the chemokine epithelial growth factor. In addition, compound 1 inhibited phosphorylation of integrin ß(1), which plays an important role in MB-MDA-231 cell adhesion and metastasis.

Crystal structure of 6-SST/6-SFT from Pachysandra terminalis, a plant fructan biosynthesizing enzyme in complex with its acceptor substrate 6-kestose.

Fructans play important roles as reserve carbohydrates and stress protectants in plants, and additionally serve as prebiotics with emerging antioxidant properties. Various fructan types are synthesized by an array of plant fructosyltransferases belonging to family 32 of the glycoside hydrolases (GH32), clustering together with GH68 in Clan-J. Here, the 3D structure of a plant fructosyltransferase from a native source, the Pachysandra terminalis 6-SST/6-SFT (Pt6-SST/6-SFT), is reported. In addition to its 1-SST (1-kestose-forming) and hydrolytic side activities, the enzyme uses sucrose to create graminan- and levan-type fructans, which are probably associated with cold tolerance in this species. Furthermore, a Pt6-SST/6-SFT complex with 6-kestose was generated, representing a genuine acceptor binding modus at the +1, +2 and +3 subsites in the active site. The enzyme shows a unique configuration in the vicinity of its active site, including a unique D/Q couple located at the +1 subsite that plays a dual role in donor and acceptor substrate binding. Furthermore, it shows a unique orientation of some hydrophobic residues, probably contributing to its specific functionality. A model is presented showing formation of a ß(2-6) fructosyl linkage on 6-kestose to create 6,6-nystose, a mechanism that differs from the creation of a ß(2-1) fructosyl linkage on sucrose to produce 1-kestose. The structures shed light on the evolution of plant fructosyltransferases from their vacuolar invertase ancestors, and contribute to further understanding of the complex structure-function relationships within plant GH32 members.

Unexpected presence of graminan- and levan-type fructans in the evergreen frost-hardy eudicot Pachysandra terminalis (Buxaceae): purification, cloning, and functional analysis of a 6-SST/6-SFT enzyme.

About 15% of flowering plants accumulate fructans. Inulin-type fructans with ß(2,1) fructosyl linkages typically accumulate in the core eudicot families (e.g. Asteraceae), while levan-type fructans with ß(2,6) linkages and branched, graminan-type fructans with mixed linkages predominate in monocot families. Here, we describe the unexpected finding that graminan- and levan-type fructans, as typically occurring in wheat (Triticum aestivum) and barley (Hordeum vulgare), also accumulate in Pachysandra terminalis, an evergreen, frost-hardy basal eudicot species. Part of the complex graminan- and levan-type fructans as accumulating in vivo can be produced in vitro by a sucrose:fructan 6-fructosyltransferase (6-SFT) enzyme with inherent sucrose:sucrose 1-fructosyltransferase (1-SST) and fructan 6-exohydrolase side activities. This enzyme produces a series of cereal-like graminan- and levan-type fructans from sucrose as a single substrate. The 6-SST/6-SFT enzyme was fully purified by classic column chromatography. In-gel trypsin digestion led to reverse transcription-polymerase chain reaction-based cDNA cloning. The functionality of the 6-SST/6-SFT cDNA was demonstrated after heterologous expression in Pichia pastoris. Both the recombinant and native enzymes showed rather similar substrate specificity characteristics, including peculiar temperature-dependent inherent 1-SST and fructan 6-exohydrolase side activities. The finding that cereal-type fructans accumulate in a basal eudicot species further confirms the polyphyletic origin of fructan biosynthesis in nature. Our data suggest that the fructan syndrome in P. terminalis can be considered as a recent evolutionary event. Putative connections between abiotic stress and fructans are discussed.

[Phenol constituents of Pachysandra terminalis and their antioxidant activity].

OBJECTIVE: To study the phenol constituents from Pachysandra terminalis and their antioxidant activities. METHOD: Constituent isolation and purification was carried by repeated column chromatography (silica gel, Toyopearl HW-40 and preparative HPLC), and their structures were elucidated on the basis of spectral data analysis. DPPH method was used to evaluate the free radical scavenging activity of the isolated compounds. RESULT: Nine phenol compounds (1-9) were isolated and their structures were identified as follow: p-hydroxybenzaldehyde (1), vanillin (2), 1-(4-hydroxy-3-methoxyphenyl) -ethanone (3), syringaldehyde (4), salicylic acid (5), p-hydroxybenzoic acid (6), ferulic acid (7), 2,3,4-trihydroxybenzoic acid (8), 3,4-dihydroxybenzoic acid (9). The isolated compounds showed obviously antioxidant activity. At the concentration of 50 micromol x L(-1), compounds 7-9 revealed DPPH free radical scavenging rates were 87.8%, 97.8% and 92%, respectively. CONCLUSION: Compounds 1-9 were isolated from this genus for the first time. They showed the significant antioxidant activity.

[Studies on the chemical constituents of Pachysandra terminalis and their antioxidant activity].

OBJECTIVE: To study the chemical constituents from Pachysandra terminalis and their antioxidant activity. METHODS: Chemical constituents were isolated by repeated column chromatography (silica gel, Toyopearl HW-40C and preparative HPLC). The structures of isolated compounds were elucidated on the basis of spectral data analysis. DPPH method was used to evaluate the free radical scavenging activity of the isolated compounds. RESULTS: Six compounds were isolated and their structures were identified as follow: 2-Phenylethyl-beta-D-glucopyranoside (1), (+)Pinoresinol-4'-O-beta-D-glucopyranoside (2), Pinoresinol (3), cis-Syringin (4), 4-hydroxy-4-(3-oxo-l-butenyl)-3,5,5-trimethylcyclohex-2-en-l-one (5), 3alpha-hydroxy-5,6-epoxy-7-megastigmen-9-one (6). Compounds 2, 4, 5 showed obviously antioxidant activity, their DPPH free radical scavenging rates were 82.50%, 87.36%, and 84.56% on the concentration of 50 micromol/L, respectively. CONCLUSION: Compounds 1-6 are isolated from this genus for the first time. Compounds 2, 4, and 5 showed significant antioxidant activities.

Pregnane alkaloids from Pachysandra axillaris.

Nine new pregnane alkaloids, pachysamines J-R (1-9), together with seven known ones, were isolated from Pachysandra axillaris. The chemical structures of the new alkaloids were elucidated by spectroscopic methods. All the compounds were evaluated for their inhibitory activities against HL-60, SMMC-7721, A-549, SK-BR-3, and PANC-1 cell lines. Compound 15 possessed moderate activities against A-549, SK-BR-3, and PANC-1 cells, with the IC(50) values of 11.17, 4.17, and 10.76 microM, respectively. Besides, compound 11 showed cytotoxicities against A-549 cell, with the IC(50) values as 24.94 microM.

Phenol constituents of Pachysandra terminalis and their antioxidant activity / 中国中药杂志

<p><b>OBJECTIVE</b>To study the phenol constituents from Pachysandra terminalis and their antioxidant activities.</p><p><b>METHOD</b>Constituent isolation and purification was carried by repeated column chromatography (silica gel, Toyopearl HW-40 and preparative HPLC), and their structures were elucidated on the basis of spectral data analysis. DPPH method was used to evaluate the free radical scavenging activity of the isolated compounds.</p><p><b>RESULT</b>Nine phenol compounds (1-9) were isolated and their structures were identified as follow: p-hydroxybenzaldehyde (1), vanillin (2), 1-(4-hydroxy-3-methoxyphenyl) -ethanone (3), syringaldehyde (4), salicylic acid (5), p-hydroxybenzoic acid (6), ferulic acid (7), 2,3,4-trihydroxybenzoic acid (8), 3,4-dihydroxybenzoic acid (9). The isolated compounds showed obviously antioxidant activity. At the concentration of 50 micromol x L(-1), compounds 7-9 revealed DPPH free radical scavenging rates were 87.8%, 97.8% and 92%, respectively.</p><p><b>CONCLUSION</b>Compounds 1-9 were isolated from this genus for the first time. They showed the significant antioxidant activity.</p>

Two new pregnanone derivatives with strong cytotoxic activity from Pachysandra axillaris.

Two new, bioactive, pregnane-based natural products, pachysanonin (= 3beta,11alpha,12beta)-12-acetoxy-3-(dimethylamino)-11-[(3,4-dimethylpent-3-enoyl)oxy]pregnan-20-one; 1) and pachysanone (= (11alpha,12beta)-12-acetoxy-11-[(3,4-dimethylpent-3-enoyl)oxy]pregnan-3,20-dion; 2) have been isolated from Pachysandra axillaris. Their structures were determined by spectroscopic methods, and, in the case of 2, by single-crystal X-ray crystallography (Figure). Compound 2 showed significant antitumor activity against Lewis lung carcinoma (LCC) tumor cells, with an IC50 value of 0.020+/-0.006 microg/ml, which is equal or even lower than those of the well-known natural antitumor agents harringtonine (0.02), homoharringtonine (0.15), and adriamycin (0.06 microg/ml; positive control).