Streptomyces alleviate abiotic stress in plant by producing pteridic acids.

Soil microbiota can confer fitness advantages to plants and increase crop resilience to drought and other abiotic stressors. However, there is little evidence on the mechanisms correlating a microbial trait with plant abiotic stress tolerance. Here, we report that Streptomyces effectively alleviate drought and salinity stress by producing spiroketal polyketide pteridic acid H (1) and its isomer F (2), both of which promote root growth in Arabidopsis at a concentration of 1.3 nM under abiotic stress. Transcriptomics profiles show increased expression of multiple stress responsive genes in Arabidopsis seedlings after pteridic acids treatment. We confirm in vivo a bifunctional biosynthetic gene cluster for pteridic acids and antimicrobial elaiophylin production. We propose it is mainly disseminated by vertical transmission and is geographically distributed in various environments. This discovery reveals a perspective for understanding plant-Streptomyces interactions and provides a promising approach for utilising beneficial Streptomyces and their secondary metabolites in agriculture to mitigate the detrimental effects of climate change.

Biosynthesis of natural and halogenated plant monoterpene indole alkaloids in yeast.

Monoterpenoid indole alkaloids (MIAs) represent a large class of plant natural products with marketed pharmaceutical activities against a wide range of indications, including cancer, malaria and hypertension. Halogenated MIAs have shown improved pharmaceutical properties; however, synthesis of new-to-nature halogenated MIAs remains a challenge. Here we demonstrate a platform for de novo biosynthesis of two MIAs, serpentine and alstonine, in baker's yeast Saccharomyces cerevisiae and deploy it to systematically explore the biocatalytic potential of refactored MIA pathways for the production of halogenated MIAs. From this, we demonstrate conversion of individual haloindole derivatives to a total of 19 different new-to-nature haloserpentine and haloalstonine analogs. Furthermore, by process optimization and heterologous expression of a modified halogenase in the microbial MIA platform, we document de novo halogenation and biosynthesis of chloroalstonine. Together, this study highlights a microbial platform for enzymatic exploration and production of complex natural and new-to-nature MIAs with therapeutic potential.

Stretching of immersed polyelectrolyte brushes in shear flow.

The way that polymer brushes respond to shear flow has important implications in various applications, including antifouling, corrosion protection, and stimuli-responsive materials. However, there is still much to learn about the behaviours and mechanisms that govern these responses. To address this gap in knowledge, our study uses in situ X-ray reflectivity to investigate how poly(styrene sulfonate) (PSS) brushes stretch and change in different environments, such as isopropanol (a poor solvent), water (a good solvent), and aqueous solutions containing various cations (Cs+, Ba2+, La3+, and Y3+). We have designed a custom apparatus that exposes the PSS brushes to both tangential shear forces from the primary flow and upward drag forces from a secondary flow. Our experimental findings clearly show that shear forces have a significant impact on how the chains in PSS brushes are arranged. At low shear rates, the tangential shear force causes the chains to tilt, leading to brush contraction. In contrast, higher shear rates generate an upward shear force that stretches and expands the chains. By analysing electron density profiles obtained from X-ray reflectivity, we gain valuable insights into how the PSS brushes respond structurally, especially the role of the diffuse layer in this dynamic behaviour. Our results highlight the importance of the initial chain configuration, which is influenced by the solvent and cations present, in shaping how polymer brushes respond to shear flow. The strength of the salt bridge network also plays a crucial role in determining how easily the brushes can stretch, with stronger networks offering more resistance to stretching. Ultimately, our study aims to enhance our understanding of polymer physics at interfaces, with a particular focus on practical applications involving polymer brushes.

Discovery of nontriterpenoids from the rot roots of Panax notoginseng with cytotoxicity and their molecular docking study and experimental validation.

Panax notoginseng (PN) is a well-known traditional Chinese medicine, with dammarane-type triterpenoid saponins characterized as major component and active ingredients, together with amino acids, flavonoids, polysaccharides, and polyacetylenes. The roots of PN are susceptible to root rot disease, which causes a huge loss and changes in the chemical components of this precious resource. In this study, sub-fractions of rot PN root extracts were preliminarily found to have admirable cytotoxicity on two human cancer cells. Further bioassay-guided isolation discovered nine new non-triterpenoids, including two novel N-methylacetamido-1-oxotetrahydropyrimidine alkaloids (1, 2), five 2H-furanones or 2H-pyranones (3-7), and two polyacetylenic alcohols (8, 9). Their structures were illuminated by extensive spectroscopic data, calculated ECD, and X-ray diffraction analysis. Among them, 3-7 were considered to be transformed from panaxatriol through the intermediates (8, 9). The new alkaloids (1, 2) displayed noteworthy cytotoxicity against five human cancer cells with IC50 values ranging from 14 to 24 µM. In silico target prediction and molecular docking studies showed that 1 and 2 may interact with EGFR, and were verified by the experimental inhibitory effect on EGFR tyrosine kinase.

Advanced Materials for Energy-Water Systems: The Central Role of Water/Solid Interfaces in Adsorption, Reactivity, and Transport.

The structure, chemistry, and charge of interfaces between materials and aqueous fluids play a central role in determining properties and performance of numerous water systems. Sensors, membranes, sorbents, and heterogeneous catalysts almost uniformly rely on specific interactions between their surfaces and components dissolved or suspended in the water-and often the water molecules themselves-to detect and mitigate contaminants. Deleterious processes in these systems such as fouling, scaling (inorganic deposits), and corrosion are also governed by interfacial phenomena. Despite the importance of these interfaces, much remains to be learned about their multiscale interactions. Developing a deeper understanding of the molecular- and mesoscale phenomena at water/solid interfaces will be essential to driving innovation to address grand challenges in supplying sufficient fit-for-purpose water in the future. In this Review, we examine the current state of knowledge surrounding adsorption, reactivity, and transport in several key classes of water/solid interfaces, drawing on a synergistic combination of theory, simulation, and experiments, and provide an outlook for prioritizing strategic research directions.

Multiple in vitro biological effects of phenolic compounds from Terminalia chebula var. tomentella.

ETHNOPHARMACOLOGICAL RELEVANCE: Terminalia chebula (TC), a well-known Indian Ayurvedic medicine introduced into China in the Sui and Tang Dynasties, has been recorded and used medicinally as Fructus Chebulae, together with its variety tomentella (TCT) in the Chinese Pharmacopoeia. They have been also used commonly for the treatment of diabetes mellitus by Tibetan medicine. AIM OF THE STUDY: To investigate the main bioactive and therapeutic principles in the fruits of TCT, based on the extensive evaluation of their anti-inflammatory and hypoglycemic activities. MATERIALS AND METHODS: The TCT fresh fruits were analyzed by HPLC and separated further by column chromatography and preparative HPLC. The isolated compounds were identified by extensive spectroscopic analyses, including 1D/2D NMR, MS, UV, IR and ECD. Anti-inflammatory activity was evaluated by inhibition of NO production in RAW264.7 cells. The specific iNOS (PDB ID: 3E7G) structure was prepared by Discovery Studio 4.0, and the molecular docking simulation was performed on GOLD (version 5.2.2). Hypoglycemic activity was measured using the substrate solution of 4-nitrophenyl-α-d-glucopyranoside enzyme and buffer solution. RESULTS: The HPLC analysis method of polyphenols in the fruits of TCT was established, and 13 main chromatographic peaks were identified, including six hydrolyzable tannins (2, 4-7, 10-11), three simple phenols (12-14), and one oleanane pentacyclic triterpene, arjungenin. Extensive chromatographic separation of TCT fresh fruits yielded 14 compounds, including one new natural hydrolyzable tannin, 2,3-(S)-HHDP-6-O-galloyl-d-glucose (1). The known compounds were identified as 10 hydrolyzable tannins (2-11) and three simple phenols (12-14). Compounds 10 (IC50 = 36.43 ± 0.21 µM), 11 (IC50 = 42.28 ± 0.09 µM) displayed stronger NO inhibitory activity than the positive control L-NMMA (IC50 = 42.34 ± 0.66 µM), while 2, 4, and 9 showed moderate inhibitory activity against NO production. Further molecular docking simulation of specific iNOS on 10 and 11, as well as five previously isolated lignans 15-19 showed that there were no obvious rules between docking results and the in vitro NO inhibitory activity for hydrolyzable tannins (10 and 11), while the mechanism of anti-inflammatory activity for lignans was related to the substitution of conjugated aldehyde groups. Moreover, most of the hydrolyzable tannins (1-2, 4-5, 9-11) and simple phenol (12) displayed stronger inhibitory effects on α-glucosidase than the positive control, quercetin (IC50 = 6.118 ± 0.071 µM), with IC50 values ranging from 0.079 to 16.494 µM. Among these bioactive isolates, the hydrolyzable tannins 2, 4-5, and 9-11, and simple phenol 12 are major chemical components in TCT fruit. CONCLUSIONS: The results showed that lignans and hydrolyzed tannins are the main active ingredients of TCT fruits, responsible for the traditional treatment of sore throat and cough. Moreover, hydrolyzed tannins and simple phenolic compounds with potential hypoglycemic activity are closely related to the ethno-pharmacological uses of TCT fruits on diabetes in Tibetan medicine.

Allelochemicals of Panax notoginseng and their effects on various plants and rhizosphere microorganisms.

Panax notoginseng (Araliaceae) is an important ginseng herb with various health benefits and a history of cultivation in southwestern China over 400 years. In recent years P. notoginseng has faced serious continuous-cropping obstacles due to its large-scale cultivation. In this study, we aim to explore the allelochemicals of P. notoginseng and their interactions with various plants and rhizosphere microorganisms. The chemical constituents of the soil cultivated with 3-year-old P. notoginseng were studied by column chromatography, spectroscopic and GC-MS analyses. We identified 13 volatile components and isolated six triterpenes (1-4, 6-7) and one anthraquinone (5). Compounds 1-7 were tested for their effects on seed germination and root elongation in P. notoginseng, corn, wheat, turnip, water spinach and Arabidopsis thaliana. We also examined the effect of compounds 1-7 on the growth of ten rhizosphere microorganisms of P. notoginseng. At a concentration of 1.0 µg mL-1, compounds 3 and 5-7 caused the death of P. notoginseng root cells and compounds 2, 6 and 7 induced the death of root cells of A. thaliana. Compounds 1-5 and 7 inhibited elongation of A. thaliana root tip cells at a concentration of 10.0 µg mL-1. Moreover, at a concentration of 0.1 mg mL-1, compounds 3, 4, 6 and 7 inhibited the growth of probiotics and promoted the growth of pathogens of P. notoginseng. These results suggest that these isolated ursane-type triterpenoid acids and anthraquinone are potential allelochemicals that contribute to continuous-cropping obstacles of P. notoginseng.

An in situ shearing x-ray measurement system for exploring structures and dynamics at the solid-liquid interface.

Revealing interfacial structure and dynamics has been one of the essential thematic topics in material science and condensed matter physics. Synchrotron-based x-ray scattering techniques can deliver unique and insightful probing of interfacial structures and dynamics, in particular, in reflection geometries with higher surface and interfacial sensitivity than transmission geometries. We demonstrate the design and implementation of an in situ shearing x-ray measurement system, equipped with both inline parallel-plate and cone-and-plate shearing setups and operated at the advanced photon source at Argonne National Laboratory, to investigate the structures and dynamics of end-tethered polymers at the solid-liquid interface. With a precise lifting motor, a micrometer-scale gap can be produced by aligning two surfaces of a rotating upper shaft and a lower sample substrate. A torsional shear flow forms in the gap and applies tangential shear forces on the sample surface. The technical combination with nanoscale rheology and the utilization of in situ x-ray scattering allow us to gain fundamental insights into the complex dynamics in soft interfaces under shearing. In this work, we demonstrate the technical scope and experimental capability of the in situ shearing x-ray system through the measurements of charged polymers at both flat and curved interfaces upon shearing. Through the in situ shearing x-ray scattering experiments integrated with theoretical simulations, we aim to develop a detailed understanding of the short-range molecular structure and mesoscale ionic aggregate morphology, as well as ion transport and dynamics in soft interfaces, thereby providing fundamental insight into a long-standing challenge in ionic polymer brushes with a significant technological impact.

Enrichment and Distribution of Pb2+ Ions in Zwitterionic Poly(cysteine methacrylate) Brushes at the Solid-Liquid Interface.

Cysteine-based polyzwitterionic brushes have been prepared via a two-step route. First, poly(allyl methacrylate) (PAMA) brushes have been grown from the surface of silicon substrates using surface-initiated atom transfer radical polymerization. The obtained PAMA brushes with free pendant vinyl groups were further modified via radical thiol-ene addition reaction to attach l-cysteine moieties. Surface ζ potential investigations on pH-responsiveness of these poly(cysteine methacrylate) (PCysMA) brushes confirm their zwitterionic character at intermediate pH range, while at pH values either below pH 3.50 or above pH 8.59, they exhibit polyelectrolyte character. Under acid (pH < 3.50) or base (pH > 8.59) conditions, they possess either cationic or anionic character, respectively. In the zwitterionic region, these PCysMA brushes show positive surface ζ potential in the presence of Pb(CH3COO)2 solutions of various concentrations. The results are in line with microscopic investigations using anomalous X-ray reflectivity (AXRR) carried out along the absorption edge of Pb2+ ions. When the photon energies were varied around the absorption L3 edge of lead (13037 eV), the Pb2+ concentration normal to the silicon substrates, as a function of depth inside PCysMA brushes, could be revealed at the nanoscale. Both ζ potential and AXRR measurements confirm the enrichment of Pb2+ ions inside PCysMA brushes, indicating the potential of PCysMA to be used as a water purification material.

GC-MS-based identification and statistical analysis of liposoluble components in the rhizosphere soils of Panax notoginseng.

Continuous cropping obstacle, mainly caused by microorganisms and organic components in soil, has become a serious problem for the plantation of Panax notoginseng (Araliaceae) due to the rapidly increased demands of this famous herbal medicine in recent decades. The rhizosphere soils cultivated with 3-year-old healthy and ill notoginseng were chemically investigated by gas chromatography-mass spectrometry (GC-MS) and compared with the corresponding soils without the plantation of notoginseng. Totally 47 liposoluble components were identified. Furthermore, the multiple statistical analysis showed that these constituents were qualitatively and quantitatively associated with the differences between the cultivated soil with P. notoginseng and the uncultivated soil. Among them, neophytadiene (4), d-α-tocopherol (38), (3ß,22E,24S)-ergosta-5,22-dien-3-ol (39), (3ß,24R)-ergost-5-en-3-ol (40), stigmasta-5,22-dien-3-ol (41), stigmast-4-en-3-one (44) and (5α)-stigmastane-3,6-dione (47) contributed most to the significant differences between the cultivated and uncultivated soils, whereas cyclopentadecane (3), octadecanoic acid methyl ester (16), docosanoic acid ethyl ester (31), nonacosane (34), 38 and 39 were found in much higher amount in the soils with ill P. notoginseng as compared to the case of those with the healthy P. notoginseng. On the other hand, liposoluble components in different cultivation areas were of great diversity; however, they were able to remain relatively consistent across the overall trend of differential substances.

Albocycline-type Macrolides with Antibacterial Activities from Streptomyces sp. 4205.

The actinomycete genus Streptomyces is characterized by producing bioactive secondary metabolites, including antibiotics. In this study, chemical and biological investigations were carried out on Streptomyces strain 4205 isolated from the paddy soil, leading to the identification and characterization of 10 albocycline-type macrolides, among which 4 compounds were new, namely albocyclines A-D (1-4). The structures of 1-10 were identified according to the 1D- and 2D-NMR spectroscopic data. Furthermore, compounds 1-10 were evaluated for antimicrobial activity. Compounds 5-7 displayed antimicrobial activities against Candidaalbicans ATCC 90028 with the same MIC value of 10.0 mg/mL and the IC50 values of 1.5, 1.0, and 1.0 mg/mL, respectively. Thus, the research on Streptomyces sp. is of vital significance for developing new antibiotic agents.

Research of Panax spp. in Kunming Institute of Botany, CAS.

Panax, a genus of the Araliaceae family, is an important herbal group in traditional Chinese medicine (TCM). Nine species and three varieties are included in the genus of Panax, in which nearly all species have been used for medicinal purposes. Among them, Panax notoginseng (Burk) F. H. Chen, Panax ginseng C. A. Meyer and Panax quinquefolius L. are the most representative and valuable herbs world-wide, with a long history of cultivation. As the main bioactive chemical constituents, saponins with different aglycones are the major components in various Panax spp., and their pharmacological activities are mainly reflected in the effects on blood system, cardio- and cerebro-vascular systems, nervous system, metabolism, and immune regulation. Researchers of Kunming Institute of Botany (KIB), Chinese Academy of Sciences (CAS), have put many efforts into conducting the investigations on Panax species. Herein, we reviewed the research progress on Panax spp. in KIB, CAS, over the past few decades, from the aspects of history and origin, phytochemistry and pharmacological activities.

Distribution and Determinants of Unmet Need for Supportive Care Among Women with Breast Cancer in China.

BACKGROUND The aim of this study was to determine the need for supportive care among women suffering from breast cancer in China and to identify its potential determinants to inform the development of effective and efficient healthcare services across different settings. MATERIAL AND METHODS In a tertiary-care hospital in Weifang, China, between July 2015 and January 2016, all women attending the Breast Cancer Clinic for regular physical examinations after treatment for breast cancer were consecutively recruited. The 34-item Supportive Care Needs Survey tool (Chinese version) (SCNS-SF34-C) was used to assess the unmet needs among participants. RESULTS Among 264 recruited patients, based on at least single-item endorsement, 60.2% had moderate to high level of need for supportive care, while only 13.3% expressed no need. Lack of information regarding health systems was the most common domain with moderate to high unmet needs, more so among rural patients (8 vs. 5 out of 10). In each information-related domain, huge unmet need was observed among all patients irrespective of urban or rural residence. Both overall and individual information-related domain-specific unmet needs were significantly higher among rural patients as opposed to their urban counterparts. Multiple regression analyses revealed a significant rural-urban variation of unmet needs. Moreover, education and post-diagnosis time duration were negatively associated with unmet needs while stage of cancer was positively associated with these unmet needs. CONCLUSIONS There is a huge burden of unmet needs for information on the healthcare system among breast cancer survivors in China. Rural residence, less education, advanced stage of cancer, and shorter duration since diagnosis were the identified determinants requiring targeted intervention.

New triterpenoid saponins from the steaming treated roots of Panax notoginseng.

Further phytochemical investigation of the steaming treated roots of Panax notoginseng (Araliaceae) led to the identification of two new dammarane-type triterpenoid saponins, notoginsenoside SP20 (1) and SP21 (2). In addition, a pair of new phenolic glycosides (3a and 3b) was also isolated together with two known compounds. Their structures were elucidated by HRESIMS, 1D- and 2D-NMR spectra. Compounds 1 and 2 showed no in vitro cytotoxicity against five human cancer cell lines (HL-60, SMMC-7712, A-549, MCF-9 and SW480).

Triterpenoids with Promoting Effects on the Differentiation of PC12 Cells from the Steamed Roots of Panax notoginseng.

The roots of Panax notoginseng, an important Chinese medicinal plant, have been used traditionally in both the raw and processed forms, due to the different chemical constituents and bioactivities found. Thirty-eight dammarane-type triterpenoid saponins were isolated from the steam-processed roots of P. notoginseng, including 18 new substances, namely, notoginsenosides SP1-SP18 (1-18). The structures of 1-18 were determined on the basis of spectroscopic analysis and acidic hydrolysis. The absolute configuration of the hydroxy group at C-24 in 1-4, 19, and 20 was determined in each case by Mo2(AcO)4-induced circular dichroism. The new compounds were found to feature a diversity of highly oxygenated side chains, formed by hydrolysis of the C-20 sugar moiety followed by dehydration, dehydrogenation, epoxidation, hydroxylation, or methoxylation of the main saponins in the raw roots. The new saponins 1, 2, 6-8, 14, and 17 and the known compounds 20-27 showed promoting effects on the differentiation of PC12 cells, at a concentration of 10 µM.