Cytotoxic Trichothecene Macrolides Produced by the Endophytic Myrothecium roridum.

Six new macrolides named myrothecines D-G (1-4), 16-hydroxymytoxin B (5), and 14'-dehydrovertisporin (6), including four 10,13-cyclotrichothecane derivatives, in addition to 12 known compounds (7-18), were isolated from three endophytic Myrothecium roridum, IFB-E008, IFB-E009, and IFB-E012. The isolated compounds were characterized by MS, NMR, CD, and single-crystal X-ray crystallography. The isolated macrolides exhibited an antiproliferation effect against chronic myeloid leukemia K562 and colorectal carcinoma SW1116 cell lines. Compounds 1-6 were cytotoxic, with IC50 values ranging between 56 nM and 16 µM. Since slight structural changes led to obvious activity differences, the CoMFA (comparative molecular field analysis) and CoMSIA (comparative molecular similarity indices analysis) methods were then used to explore the 3D QSAR (three-dimensional quantitative structure-activity relationship) of these macrolides. The result showed that the steric, electrostatic, hydrophobic, and H-bond acceptor factors were involved in their cytotoxicity and provided an in-depth understanding of the structure-activity relationships of these metabolites.

Cytotoxic Tricycloalternarene Compounds from Endophyte Alternaria sp. W-1 Associated with Laminaria japonica.

The chemical investigation of the culture filtrate of endophyte Alternaria sp. W-1 associated with Laminaria japonica provided a new tricycloalternarene compound, 2H-(2E)-tricycloalternarene 12a (1), together with five known analogs: (2E)-tricycloalternarene 12a (2), tricycloalternarene 3a (3), tricycloalternarene F (4), 15-hydroxyl tricycloalternarene 5b (5), and ACTG-Toxin D (6). In vitro cytotoxicity against the human hepatocellular carcinoma cell line SMMC-7721 and the human gastric carcinoma cell line SGC-7901 was evaluated by the MTT method. Compounds 1, 3, and 4 inhibited the growth of SMMC-7721 cells with IC50 values of 49.7 ± 1.1, 45.8 ± 4.6, and 80.3 ± 3.8 µg/mL, respectively, while the IC50 value of the positive control cisplatin was 6.5 ± 0.5 µg/mL. Compounds 3 and 6 also showed moderate anti-proliferation activity against SGC-7901 cells with IC50 values of 53.2 ± 2.9 and 35.1 ± 0.8 µg/mL, respectively, while the IC50 value of cisplatin was 4.5 ± 0.6 µg/mL. Further studies revealed that the in vitro anticancer activity of compound 3 to SMMC-7721 cells was related to G1 phase cell cycle arrest and cell apoptosis, and the induced apoptosis was involved in both the mitochondrial pathway and the death receptor pathway. This is the first report on the anticancer mechanism of tricycloalternarene compounds.

[Chemical constituents of liquid culture of symbiotic Chaetomium globosum ML-4 of oyster and their in vitro antitumor activity].

Isolation and purification of chemical constituents of liquid culture of symbiotic Chaetomium globosum ML-4 of oyster was performed through silica gel column chromatography, gel filtration over Sephadex LH-20, preparative TLC and HPLC. Five compounds were obtained and their structures were determined as chaetoglobosin V(1), chaetoglobosin Vb(2), tyrosol(3), 5-methyluracil(4)and uracil(5), respectively, based on HR-MS and NMR data and comparison with literatures. In vitro cytotoxicity of compounds against human hepatocellular carcinoma cell line SMMC-7721 were measured byMTT method, and results showed that compound 1 could obviously inhibit the proliferation of SMMC-7721 cells with an IC50 value of 60.5 mg•L⁻¹, while the IC50 value of positive control cisplatin was 19.96 mg•L⁻¹. Further studies discovered that compound 1 could lead to G2 phase arrest in SMMC-7721 cells and induce SMMC-7721 cells apoptosis. The ratio of Bcl-2/Bax in SMMC-7721 cells was decreased. The expression of protein Caspases-3,-8,-9 was improved and the expression and phosphorylation level of Akt were reduced. Aforementioned results revealed that in vitro antitumor activity of compound 1 against SMMC-7721 cells were related to G2 phase cell cycle arrest and induced-apoptosis. The induced-apoptosis was involved in both the mitochondrial pathway and the death receptor pathway and connected with activity decline of PI3K/Akt signaling pathway.

A new trichothecene from Myrothecium roridum QDFE005, a symbiotic fungus isolated from Mactra chinensis.

A new trichothecene, 12'-episatratoxin H (1), together with three known analogs: roridin A (2), 16-hydroxyroridin E (3), and roridin E (4), was isolated from the culture broth of the symbiotic fungus Myrothecium roridum QDFE005, which was isolated from Mactra chinensis. Their structures were elucidated on the basis of spectroscopic methods, including 1D and 2D NMR (COSY, HMQC, and HMBC) techniques. Compound 1 exhibited significant cytotoxicity against the human tumor cell lines KB and HepG2 with IC50 values of 1.42 and 2.27 µM, respectively.

Effects of strip cropping with reducing row spacing and super absorbent polymer on yield and water productivity of oat (Avena sativa L.) under drip irrigation in Inner Mongolia, China.

With the serious shortage of water resources and the development of water-saving agriculture, the application of drip irrigation has been paid more and more attention. But there was lack of oat planting methods suitable for drip irrigation, currently. In order to establish an efficient oat planting method for drip irrigation, a study was conducted at Agriculture and Forestry Sciences of Ulanqab, Inner Mongolia during the season (2019-2020) to evaluate the effect of strip cropping with reducing row spacing and super absorbent polymer on the yield and water use efficiency of oat. To conduct the field trials, a split plot system in three replications was established. Three planting patterns were in the main plots, including conventional cropping with 20 cm equal row spacing (PA), strip cropping with the 15 cm row spacing (PB) and strip cropping with the 10 cm row spacing (PC), and two super absorbent polymer levels were in the subplots, including 22.5 kg ha-2 (Y) and 0 (N). The results showed that, compared with PA, PB and PC both decreased the irrigation volumes by 4.5-18.4 mm, and the irrigation volumes of PB was lower than that of PC. When super absorbent polymers were applied, compared with PA, PB significantly increased grain yield and above-ground biomass, but PC had the opposite effects. The grain yield and above-ground biomass of PB significantly increased by 16.65% and 7.31% on average in two years, respectively. And the increasing of grain yield was attributed by the significant increasing of pike number and kernel number per spike. But when super absorbent polymers were not applied, PB had no significant effects on grain yield and above-ground biomass. PB also had the significant effects on regulating water use of oats weather or not super absorbent polymers were applied, it significantly increased the precipitation ratio by 2.64% (PBY) and 2.13% (PBN) and decreased irrigation ration by 3.32% (PBY) and 5.28% (PBN) on average in two years. Although PB and PC both decreased the total evapotranspiration, but PB increased WUE and PC deceased WUE. The WUE of PB increased by 19.70% (PBY) and 9.87% (PBN) on average in two years. Also PB had the highest economic benefits in all treatments. In conclusion, a drip irrigation oat planting pattern was proposed, which the row spacing is 15 cm, adjusted the equal row spacing planting to 8-row strip planting, with a belt spacing of 30 cm, combined with the application of 22.5 kg ha-2 applying super absorbent polymers. And this oat planting pattern is a viable strategy to improve oat productivity.

Bis[2-(cyclo-pentyl-imino-meth-yl)-4-nitro-phenolato-κN,O]cobalt(II).

In the title compound, [Co(C(12)H(13)N(2)O(3))(2)], the Co(II) ion is situated on a twofold rotation axis and is coordinated by two N and two O atoms from two symmetry-related Schiff base 2-(cyclo-pentyl-imino-meth-yl)-4-nitro-phenolate ligands (L) in a distorted tetra-hedral geometry. The cyclo-pentyl ring in L is disordered over two conformations in a 0.640 (19):0.360 (19) ratio.

Benzophenones from Guignardia sp. IFB-E028, an endophyte on Hopea hainanensis.

The first natural S-containing benzophenone dimer, named guignasulfide (3), was isolated from the culture of Guignardia sp. IFB-E028, an endophytic fungus residing in healthy leaves of Hopea hainanensis. Its structure was determined through correlative analyses of its MS, 1D- and 2D-NMR spectroscopic data. Two other known benzophenone derivatives, monomethylsulochrin and rhizoctonic acid (1 and 2, resp.) were also isolated. Guignasulfide (3) was more active against the human liver cancer cell line HepG2 (IC(50) value: 5.2+/-0.4 microM) than metabolites 1 and 2 (IC(50) values: 63.5+/-0.6 and 60.2+/-0.5 microM); compounds 1-3 showed also moderately inhibitory effects on the human bacterial pathogen Helicobacter pylori with MIC values of 28.9+/-0.1, 60.2+/-0.4, and 42.9+/-0.5 microM, respectively.

Maillard reaction in protein - polysaccharide coacervated microcapsules and its effects on microcapsule properties.

The occurrence of Maillard reaction in protein - polysaccharide coacervated microcapsules and its effects on microcapsule properties were investigated. Vitamin E microcapsules were prepared by soybean protein isolate - chitosan coacervation at 50 °C, 70 °C, or 90 °C for 12 h in the presence of maltose. Chromatic and furosine measurements revealed that Maillard reaction occurred in the microcapsules and was favored by high incubation temperatures. The three coacervation temperatures did not destroy the microcapsule structure, but improved the microencapsulation efficiency and microencapsulation yield instead. The microcapsules exhibited decreased aggregation and the increased absolute zeta potential and particle size were believed contribute to this improvement. Stability analysis demonstrated that the microcapsules possessed enhanced resistance to dissolution in water and improved storage stability than control microcapsules. It is concluded that coacervation at a temperature high enough to initiate Maillard reaction is a promising way to improve the physiochemical properties of protein - polysaccharide coacervated microcapsules.

3-Bromo-N'-(3,5-dibromo-2-hydroxy-benzyl-idene)benzohydrazide methanol solvate.

The title compound, C(14)H(9)Br(3)N(2)O(2)·CH(4)O, was prepared by the reaction of 3,5-dibromo-2-hydroxy-benzaldehyde and 3-bromo-benzohydrazide in methanol. The asymmetric unit of the crystal consists of a Schiff base mol-ecule and a methanol mol-ecule of crystallization. The dihedral angle between the two benzene rings is 5.5 (2)°. An intra-molecular O-H⋯N hydrogen bond is observed. In the crystal structure, pairs of adjacent Schiff base mol-ecules are linked by two methanol mol-ecules through inter-molecular N-H⋯O and O-H⋯O hydrogen bonds.

4-{Eth-yl[(E)-4-(4-pyridylvin-yl)phenyl]-amino}benzaldehyde.

In the title mol-ecule, C(22)H(20)N(2)O, the central aromatic ring forms dihedral angles of 45.30 (2) and 69.43 (2)°, respectively, with the outer pyridine and benzene rings. In the crystal structure, weak inter-molecular C-H⋯O inter-actions link the mol-ecules into layers parallel to the ab plane.

Dibromido{2-[2-(piperidinium-1-yl)ethyl-imino-meth-yl]phenolato}zinc(II) monohydrate.

The asymmetric unit of the title compound, [ZnBr(2)(C(14)H(20)N(2)O)]·H(2)O, consists of a mononuclear Schiff base zinc(II) complex mol-ecule and a solvent water mol-ecule. The Zn(II) atom is four-coordinated in an approximately tetra-hedral geometry, binding to the imine N and phenolate O atoms of the neutral zwitterionic Schiff base ligand and to two terminal Br(-) anions. In the crystal structure, mol-ecules are linked through inter-molecular O-H⋯Br and O-H⋯O hydrogen bonds, forming chains running along the b axis.

[Distribution of Redox Zone at Different Water Layers in the Presence of Periphyton and the Responsible Microorganisms].

So far, many types of carriers (such as artificial mat, industrial soft carriers) have been widely used in removing pollutants, purifying water quality via the periphyton attached on the surface of these carriers. In the presence of periphyton, the distribution of redox zone at different water layers is directly or indirectly associated with the removal rate of pollutants. Therefore, it is more practically significant to study the distribution of redox zone at different water layers and the microbial diversity in the presence of periphyton. In this study, the pilot experiment was performed in a simulated water column bioreactor. Firstly, the eutrophic water collected from XuanWu Lake was added into the simulated water column bioreactor. The industrial soft carriers were then suspended into the water column in order to enhance the growth of periphyton. After periphyton gained a steady growth state, the oxidation reduction zones (redox zones) and the responsible microorganisms at different water layers were monitored. The results showed that five sequent redox zones (i. e. oxygen reduction, nitrate reduction, iron reduction, methanogenic and sulfate reduction zones, respectively) appeared in different water layers from top-down in the presence of periphyton and their responsible terminal electron acceptors were O2, NO3(-), Fe3+, CO2 and SO4(2-) respectively. The indicators of the different zones were DO, NO2(-), Fe(2+), HCO3(-) and sulfide, and the highest concentrations were 11.290 mg x L(-1), 4.950 mg x L(-1), 38.326 mg x L(-1), 120.000 mg x L(-1) and 12.180 mg x L(-1), respectively. The results of microbiological characteristics tested by Biolog EcoPlate technology revealed that there were significant differences in the composition, metabolic activity, carbon utilization of periphyton at different water layers, causing the difference in the distribution of redox zones at different water layers. These findings implies that study on the distribution of redox zones and microbiological characteristics in the presence of periphyton provides a better understanding that periphyton is capable of improving water quality at different layer, and also provides some theoretical basis for the development of technology for purifying water quality based on periphyton.

Bioactive metabolites from Guignardia sp., an endophytic fungus residing in Undaria pinnatifida.

AIM: To isolate new and/or bioactive constituents from EtOAc extract of liquid culture of endophyte Guignardia sp. from the leaves of Undaria pinnatifida (Harv.) Sur. METHODS: Isolation and purification were performed through silica gel column chromatograph, Sephadex LH-20 and reversed-phase ODS column and the structures of the compounds obtained were identified through a combination of spectral and chemical methods (IR, MS, (1)H and (13)C NMR). In vitro bioactive assays including antifungal activity against three human pathogenic fungi Microsporum canis, Tricophyton rubrum and Epidermophyton floccosom and cytotoxic activity against the human nasopharyngeal epidermoid tumor KB cell line were evaluated. RESULTS: Seven compounds have been obtained from the liquid culture of the title endophyte: ergosterol peroxide (6, 22-diene-5, 8-epidioxyergosta-3-ol) (1), ergosterol (2), cyclo-(Tyr-Leu) (3), cyclo-(Phe-Phe) (4), cyclo-(Val-Leu) (5), cyclo-(Phe-Pro) (6) and cyclo-(Leu-Ile) (7). Compounds 1-3 and 6 inhibited the growth of M. canis with MICs of 10.0, 20.0, 50.0 and 5.0 µg·mL(-1), respectively and compounds 1, 2 and 6 against T. rubrum with MICs of 15.0, 20.0 and 10.0 µg·mL(-1), respectively and 1 and 6 against E. floccosom with MICs of 20.0 and 50.0 µg·mL(-1), respectively. In addition, compounds 1, 3 and 6 exhibited cytotoxic activity against KB cell line with IC(50) of 20.0, 10.0, 10.0 µg·mL(-1), respectively. CONCLUSION: Compounds 1-7 were obtained from Guignardia sp. of U. pinnatifida for the first time, and compounds 1 and 6 had potent cytotoxic and antifungal activity.

Characterization of graphislactone A as the antioxidant and free radical-scavenging substance from the culture of Cephalosporium sp. IFB-E001, an endophytic fungus in Trachelospermum jasminoides.

The extracts derived from cultures of 1626 endophytic strains harbored in Trachelospermum jasminoides were assayed for more potent antioxidant and/or free radical-scavenging agents. The free radical-scavenging assessment was carried out using l,l-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical assays, and the antioxidant actions on linoleic acid and human low-density lipoprotein (LDL) models. After extensive spectroscopic analyses, graphislactone A was characterized as the most bioactive secondary metabolite of endophytic Cephalosporium sp. IFB-E001 with its free radical-scavenging (in a dose-dependent manner) and antioxidant activities ascertained in vitro to be stronger than those of butylated hydroxytoluene (BHT) and ascorbic acid, the two positive references coassayed in the study. From the demonstrated efficacy of graphislactone A in preventing and protecting against oxidative injury, it can be predicted that this metabolite could be a potential agent in the management of oxidative damage-initiated diseases.