Screening and isolation of quorum sensing inhibitors of Pseudomonas aeruginosa from Phellodendron amurense extracts using bio-affinity chromatography.

Drug-resistant bacterial infections pose a significant challenge in the field of bacterial disease treatment. Finding new antibacterial pathways and targets to combat drug-resistant bacteria is crucial. The bacterial quorum sensing (QS) system regulates the expression of bacterial virulence factors. Inhibiting bacterial QS and reducing bacterial virulence can achieve antibacterial therapeutic effects, making QS inhibition an effective strategy to control bacterial pathogenicity. This article mainly focused on the PqsA protein in the QS system of Pseudomonas aeruginosa. An affinity chromatography medium was developed using the SpyTag/SpyCatcher heteropeptide bond system. Berberine, which can interact with the PqsA target, was screened from Phellodendron amurense by affinity chromatography. We characterized its structure, verified its inhibitory activity on P. aeruginosa, and preliminarily analyzed its mechanism using molecular docking technology. This method can also be widely applied to the immobilization of various protein targets and the effective screening of active substances.

Superhydrophobic Metal-Organic Framework-Based Composite Featuring Removal of Hydrophobic Drugs and Pesticides and Antibacterial Activities.

The widespread use and contamination of natural sources by new-generation drugs and pesticides have enhanced concern about environmental pollution. Understanding the above importance, we developed a superhydrophobic metal-organic framework (MOF) (SHMOF': [Zr6O4(OH)4(BDC-NH-CO-R)2.4(BDC-NH2)0.6(CF3COO)6]·2.5H2O·4DMF) for ecological remediation via adsorption-based separation of hydrophobic drugs (flurbiprofen) and pesticides (fluazinam). The newly developed SHMOF' has a high adsorption capacity toward flurbiprofen and fluazinam, i.e., 435 and 575 mg/g, respectively. The adsorption equilibrium time of the MOF is very short (15 and 10 min for flurbiprofen and fluazinam, respectively). The outstanding superhydrophobic nature of the MOF was employed to separate flurbiprofen and fluazinam from highly alkaline and acidic media and environmental water samples. The SHMOF' has excellent selectivity toward the adsorption-based separation of flurbiprofen and fluazinam in the coexistence of common analytes. Again, we developed a polypropylene (PP) fabric-based composite of SHMOF' (SHMOF'@PP) to separate the hydrophobic targeted analytes by using a zero-energy-consuming filtration-based separation method, which made this separation process cost-efficient and user-friendly. Moreover, Ag nanoparticles were doped to the superhydrophobic composite. The Ag-doped reusable SHMOF'@PP@Ag composite exhibited excellent bacterial antiadhesion and antibacterial properties toward Staphylococcus aureus bacteria.

Diversity of endophytic bacteria with antimicrobial potential isolated from marine macroalgae from Yacila and Cangrejos beaches, Piura-Peru.

Endophytic bacteria found in marine macroalgae have been studied for their potential antimicrobial activity, consequently, they could serve as a valuable source of bioactive compounds to control pathogenic bacteria, yeasts, and fungi. Algae endophytic bacteria were isolated from Caulerpa sp., Ulva sp., Ahnfeltiopsis sp., and Chondracantus chamissoi from Yacila and Cangrejo Beaches (Piura, Peru). Antimicrobial assays against pathogenic bacteria were evaluated using cross-culture, over-plate, and volatile organic compound tests. Afterward, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of selected crude extracts were determined, also ITS molecular analysis, antifungal activity, and PCR of iturin, fengycin, and surfactin genes were performed for bacteria strains exhibiting better activity. Forty-six algae endophytic bacteria were isolated from algae. Ten strains inhibited gram-positive pathogenic bacteria (Enterococcus faecalis, Staphylococcus epidermidis, S. aureus, and Listeria monocytogenes), and 12 inhibited gram-negative bacteria (Escherichia coli and Salmonella enteric sv typhimurium). Bacteria with better activity belong to Bacillus sp., Kluyvera ascorbata, Pantoea agglomerans, Leclercia adecarboxylata, and Enterobacter sp., which only four showed antifungal activities against Candida albicans, C. tropicalis, Colletotrichium sp., Fusarium sp., Fusarium oxysporum, and Alternaria sp. Furthermore, K. ascorbata YAFE21 and Bacillus sp. YCFE4 exhibited iturin and fengycin genes. The results indicate that the algae endophytic bacteria found in this study, particularly K. ascorbata YAFE21, Bacillus sp. YCFR6, L. adecarboxylata CUFE2, Bacillus sp. YUFE8, Enterobacter sp. YAFL1, and P. agglomerans YAFL6, could be investigated as potential producers of antimicrobial compounds due to their broad activity against various microorganisms.

Manniosides G-J, New Ursane- and Lupane-Type Saponins from Schefflera mannii (Hook.f.) Harms.

Four previously unreported triterpenoid saponins named 3ß-hydroxy-23-oxours-12-en-28-oic acid 28-O-ß-D-glucopyranosyl ester (mannioside G) (1), 23-O-acetyl-3ß-hydroxyurs-12-en-28-oic acid 28-O-ß-D-glucopyranosyl ester (mannioside H) (2), ursolic acid 28-O-[α-L-rhamnopyranosyl-(1→4)-ß-D-glucopyranosyl-(1→6)-ß-D-glucopyranosyl] ester (mannioside I) (3), and 3ß-hydroxy-23-oxolup-20(29)-en-28-oic acid 28-O-ß-D-glucopyranosyl ester (mannioside J) (4) were isolated as minor constituents from the EtOAc soluble fraction of the MeOH extract of the leaves of Schefflera mannii along with the known compounds 23-hydroxyursolic acid 28-O-ß-D-glucopyranosyl ester (5), ursolic acid 28-O-ß-D-glucopyranosyl ester (6), pulsatimmoside B (7) betulinic acid 28-O-[α-L-rhamnopyranosyl-(1→4)-ß-D-glucopyranosyl-(1→6)-ß-D-glucopyranosyl] ester (8), 23-hydroxy-3-oxo-urs-12-en-28-oic acid (9), hederagenin (10), ursolic acid (11), betulinic acid (12), and lupeol (13). Their structures were elucidated by a combination of 1D and 2D NMR analysis and mass spectrometry. The MeOH extract, the EtOAc and n-BuOH fractions, and some of the isolated compounds were evaluated for their antibacterial activity against four bacteria: Staphylococcus aureus ATCC1026, Staphylococcus epidermidis ATCC 35984, Escherichia coli ATCC10536, and Klepsiella pnemoniae ATCC13882. They were also screened for their antioxidant properties, but no significant results were obtained.

Bactofencin YH, a novel bacteriocin with high inhibitory activity against clinical Streptococcus species.

Strain Lactiplantibacillus plantarum D1 with bacteriocin producing ability was found in the intestine of Gambusia affinis. The bacteriocin was found to have high inhibitory activity against multiple Streptococcus species and several other Gram-positive and Gram-negative bacteria. Bacteriocin was purified from culture supernatant by ion-exchange chromatography, Sep-Pak C18 cartridge, and reverse-phase high-performance liquid chromatography (RP-HPLC). Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectral analysis determined that purified bacteriocin has a molecular mass of 2,731 Da. A partial N-terminal sequence KRKKHKXQIYNNGM was obtained from the Edman analysis. The N-terminal sequence was employed to search against a translation of the draft genome of strain D1. The translated full amino acid sequence of the mature peptide is as follows: NH2- KRKKHKCQIYNNGMPTGQYRWC, which has a molecular weight of 2738 Da. A BLAST search revealed that this bacteriocin was most similar to bactofencin A but differed from it with three amino acid residues. No identical peptide or protein has been previously reported, and this peptide, termed bactofencin YH, was therefore considered to be a new bacteriocin produced by Lactiplantibacillus plantarum D1.

Isolation and identification of antimicrobial multicyclic terpenoids from the medicinal plant Salvia officinalis and development of a formulation against clinical Staphylococcus aureus strains.

Staphylococcus aureus, particularly multi-drug resistant strains, presents significant challenges in dairy farming due to its role in causing bovine mastitis, which leads to substantial economic losses and limited treatment options. Seeking alternative therapies, we investigated the potential of a topical formulation derived from the medicinal herb Salvia officinalis to combat S. aureus growth and biofilms associated with bovine mastitis. Through systematic extraction in different solvents and fractionation by column chromatography, we isolated and identified three key multicyclic terpenoids-ferruginol, sugiol, and sclareol-exhibiting significant antimicrobial activity. The formulation effectively inhibited biofilm formation, with minimum inhibitory concentration (MIC) values ranging from 0.09 to 0.74 mg ml-1 against clinical S. aureus strains, comparable to or lower than those of the pure compounds. Moreover, it displayed robust anti-adhesive properties, reducing biofilm formation by 20%-79% at subinhibitory concentrations. Furthermore, the formulation successfully disrupted pre-existing biofilms, achieving reductions ranging from 30% to 82%. Cytotoxicity assays confirmed the safety of the formulation on mammary epithelial cells, with cell viability maintained at 100% at MIC. Our findings underscore the therapeutic potential of Sa. officinalis-derived compounds in managing bovine mastitis caused by S. aureus, emphasizing their antimicrobial efficacy and safety profile.

Bioactive substance contents and therapeutic potential for skin inflammation of an herbal gel containing Derris reticulata and Glycyrrhiza glabra.

CONTEXT: Derris reticulata Craib. and Glycyrrhiza glabra L., of the Fabaceae, have been used as active components in Thai herbal formulas for the treatment of fever and skin diseases. OBJECTIVE: To evaluate the physicochemical and pharmacological properties of the developed herbal gel formulation containing the combined extract from D. reticulata stem wood and G. glabra root (RGF). MATERIALS AND METHODS: The potential of the herbal gel formulation containing RGF (8% w/w) as the active ingredient was studied by evaluating the anti-inflammatory, antioxidant, and anti-Staphylococcus aureus activities using quantitative reverse transcription-polymerase chain reaction assay, spectrophotometric method, and broth microdilution technique, respectively. The reference standards for the biological testing included Nω-nitro-L-arginine (L-NA), ascorbic acid, catechin, and penicillin G. The stability study of the RGF herbal gel was performed by a heating-cooling test (at 45 °C for 24 h and at 4 °C for 24 h/1 cycle; for 6 cycles), and the bioactive marker compounds in the herbal gel were investigated by the HPLC technique. RESULTS: RGF showed promising pharmacological effects, particularly on its anti-inflammatory property (IC50 73.86 µg/mL), compared to L-NA (IC50 47.10 µg/mL). The RGF-containing gel demonstrated anti-inflammatory (IC50 3.59 mg/mL) and free radical scavenging effects (IC50 0.05-4.39 mg/mL), whereas it had no anti-S. aureus activity (MIC > 10 mg/mL). The active ingredient in the developed herbal gel significantly inhibited lipopolysaccharide-induced nitric oxide production by downregulating iNOS mRNA levels. The contents of the bioactive markers in the RGF gel (lupinifolin and glabridin) did not change significantly after stability testing. DISCUSSION AND CONCLUSIONS: The RGF-containing gel has potential to be further developed as an herbal product for the treatment of skin inflammation.

Anti-Biofilm Extracts and Molecules from the Marine Environment.

Pathogenic bacteria and their biofilms are involved in many diseases and represent a major public health problem, including the development of antibiotic resistance. These biofilms are known to cause chronic infections for which conventional antibiotic treatments are often ineffective. The search for new molecules and innovative solutions to combat these pathogens and their biofilms has therefore become an urgent need. The use of molecules with anti-biofilm activity would be a potential solution to these problems. The marine world is rich in micro- and macro-organisms capable of producing secondary metabolites with original skeletons. An interest in the chemical strategies used by some of these organisms to regulate and/or protect themselves against pathogenic bacteria and their biofilms could lead to the development of bioinspired, eco-responsible solutions. Through this original review, we listed and sorted the various molecules and extracts from marine organisms that have been described in the literature as having strictly anti-biofilm activity, without bactericidal activity.

Retention mechanisms of dipeptides on superficially porous particle vancomycin- and teicoplanin-based chiral stationary phases.

Chromatographic behavior of new chiral stationary phases (CSPs) Chiral-T and Chiral-V with teicoplanin and vancomycin antibiotics grafted onto superficially porous silica particles was studied in relation to dipeptide (DP) stereoisomers. The unbuffered water-methanol solutions were used as mobile phases (MPs). The effects of physical properties and molecular structure of analytes and selectors on retention and separation of DP stereoisomers are discussed herein. Chiral-T was evinced to exhibit high enantioselectivity, with highest α values attaining 16.5, 18.8 and 20.4 for Gly-Leu, dd/ll-Phe-Leu and ld/dl-Ala-Ala. At this point, Chiral-V did not exhibit enantioselectivity towards DP stereoisomers. The effect of MP composition on retention and enantioseparation of DPs was investigated. Lipophilicity of DPs was found to be an essential factor in the dependence of their retention vs. methanol concentration in МPs. Lipophobic DPs were eluted more quickly by water-rich solvents, with lipophilic DPs exhibiting an asymmetric U-shaped, or a descending dependence of retention factor vs. the methanol percentage on Chiral-T or Chiral-V, respectively. A theoretical model taking into account interaction of both solvents of a binary MP with both an analyte and adsorption sites was successfully applied so as to approximate and interpret the dependences of DP retention (monotonic and U-shaped) vs. a modifier content in MP. Water molecules were evinced to predominantly participate in competitive adsorption with DP molecules. The model predicted better solvation of lipophilic DPs by methanol and better solvation of lipophobic DPs by water. An attempt was made to verify the possibility of modeling by molecular docking the processes occurring during interaction between DP stereoisomers and CSPs, including consideration of the influence of competitive binding of eluent molecules in selector cavity.

Large-pore covalent organic framework as solid phase extraction absorbentforefficientdetermination of polypeptide antibiotics in animal-derived foods.

The precise determination of polypeptide antibiotics (PPTs) in foods has been always challenging because of the interference of various endogenous peptides in complex matrix. Herin, a novel large-pore covalent organic framework (TABPT-SPDA-COF) with accessible pore size of 7.9 nm was synthesized as a solid phase extraction (SPE) absorbent for efficiently enriching four PPTs existed in foods originating from animals. The parameters of SPE process were systematically optimized. Subsequently, four PPTs were determined by UHPLC-MS/MS. Under the optimal conditions, TABPT-SPDA-COF shows outstanding enrichment capacity for PPTs in contrast to commercial absorbents ascribed to size selectivity and multiple interaction effects. The method exhibits excellent linear range (0.005-100 ng mL-1), satisfactory limits of detection (0.1 pg mL-1) as well as relative recoveries (86.2-116 %). This work offers a practicable platform to monitor trace PPTs from complex animal-derived foodstuffs.

In vitro and in silico evaluation of bioactivities and chemical composition of the aerial parts of Anchusa officinalis L. methanol extract.

The main objective of the study is to evaluate the antioxidant, anticancer, and antimicrobial activities of Anchusa officinalis L. in vitro and in silico. The dried aerial parts of A. officinalis L. were extracted with methanol. Total phenolic and flavonoid content was analyzed. Antioxidant and antimicrobial effects were tested against both gram-positive and gram-negative bacteria. Gas chromatography-mass spectrometry analysis revealed the presence of 10 phytochemical compounds, and cyclobutane (26.07%) was identified as the major photochemical compound. The methanol extract exhibited the maximum amount of total phenolic content (118.24 ± 4.42 mg QE/g dry weight of the dry extract) (R2 = 0.994) and the total flavonoid content was 94 ± 2.34 mg QE/g dry weight of the dry extract (R2 = 0.999). The IC50 value for 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid was 107.12 ± 3.42 µg/mL, and it was high for 1,1-diphenyl-2-picryl hydrazyl (123.94 ± 2.31 µg/mL). The IC50 value was 72.49 ± 3.14 against HepG2 cell lines, and a decreased value was obtained (102.54 ± 4.17 g/mL) against MCF-7 cell lines. The methanol extract increased the expression of caspase mRNA and Bax mRNA levels when compared to the control experiment (p < .05). The conclusions, A. officinalis L. aerial parts extract exhibited antibacterial, antifungal, and antioxidant activities.

Application of Natural Antibacterial Plants in the Extraction of Uranium from Seawater.

Marine biofouling directly affects the performance and efficiency of uranium (U(VI)) extraction from seawater. Compared to traditional chemical methods, natural plant extracts are generally biodegradable and nontoxic, making them an environmentally friendly alternative to synthetic chemicals in solving the marine biofouling problem. The effectiveness of natural antibacterial plants (i.e., pine needle, peppermint, Acorus gramineus Soland, Cacumen platycladi, and wormwood) in solving the marine biofouling problem was evaluated in this work. Experimental results showed that natural antibacterial plants could kill Vibrio alginolyticus in solution and effectively solve the marine biofouling problem of U(VI) extraction. To improve the adsorption capacity of natural plants for U(VI) in seawater, poly(vinylphosphonic acid) (PVPA) was modified on natural antibacterial plant surfaces by irradiation grafting technology. PVPA and natural antibacterial plants work as active sites and base materials for the U(VI) extraction material, respectively. The recovery performance of PVPA/pine needle for U(VI) was preliminarily studied. Results show that the adsorption of U(VI) on PVPA/pine needle follows pseudo-second-order and Langmuir models, and the maximum adsorption capacity is 111 mg/g at 298 K and pH 8.2.

Tunicamycins from Marine-Derived Streptomyces bacillaris Inhibit MurNAc-Pentapeptide Translocase in Staphylococcus aureus.

Four tunicamycin class compounds, tunicamycin VII (1), tunicamycin VIII (2), corynetoxin U17a (3), and tunicamycin IX (4), were isolated from the culture broth of the marine-derived actinomycete Streptomyces sp. MBTG32. The strain was identified using the 16S rDNA sequencing technique, and the isolated strain was closely related to Streptomyces bacillaris. The structures of the isolated compounds were elucidated based on spectroscopic data and comparisons with previously reported NMR data. Compounds 1-4 showed potent antibacterial activities against Gram-positive bacteria, especially Staphylococcus aureus, with MIC values of 0.13-0.25 µg/mL. Through a recombinant enzyme assay and overexpression analysis, we found that the isolated compounds exerted potent inhibitory effects on S. aureus MurNAc-pentapeptide translocase (MraY), with IC50 values of 0.08-0.21 µg/mL. The present results support that the underlying mechanism of action of tunicamycins isolated from marine-derived Streptomyces sp. is also associated with the inhibition of MraY enzyme activity in S. aureus.

Undescribed polyketides from endophytes associated with the critically endangered conifer Abies beshanzuensis.

Four undescribed polyketides, beshanzones A (1) and B (2) as well as beshanhexanols A (3) and B (4), along with three known ones (5-7) were isolated from the rice fermentation of two endophytic fungi associated with the critically endangered Chinese endemic conifer Abies beshanzuensis. γ-Butyrolactone derivatives 1, 2, and 5 were isolated from Phomopsis sp. BSZ-AZ-2, an interesting strain that drawn our attention this time. The cyclohexanol derivatives 3, 4, 6, and 7 were obtained during a follow-up investigation on Penicillium commune BSZ-P-4-1. The chemical structures including absolute configurations of compounds 1-4 were determined by spectroscopic methods, Mo2(OAc)4 induced electronic circular dichroism (IECD), GIAO NMR calculations and DP4+ probability analyses. In particular, compound 2 contains a novel 5/5 bicyclic ring system, which might be biogenetically derived from the known compound 5 through hydrolysis followed by an Aldol reaction. All isolates were evaluated for their antimicrobial activities against a small panel of bacterial and fungal pathogens. Compounds 6 and 7 showed moderate inhibitory activities against Candida albicans, with MIC values of 16 and 32 µg/mL, respectively.

Limonium brasiliense rhizomes extract against virulence factors of Porphyromonas gingivalis: Inhibition of gingipains, bacterial adhesion, and biofilm formation.

Periodontitis is clinically characterized by destruction of the tooth support system and tooth loss. Porphyromonas gingivalis (Pg) plays a dominant role in periodontitis. Fractions and isolated compounds from an acetone-water extract of the roots of Limonium brasiliense (Lb) were tested in vitro for their anti-adhesive capacity against Pg on human KB buccal cells, influence on gingipains, the main virulence factors of Pg, and biofilm formation. Fractions EAF and FLB7 (50 µg/mL) reduced the bacterial adhesion of Pg to KB cells significantly (63 resp. 70%). The proanthocyanidin samarangenin A inhibited the adhesion (72%, 30 µM), samarangenin B (71%, 20 µM), and the flavan-3-ol epigallocatechin-3-O-gallate (79%, 30 µM). Fraction AQF, representing hydrophilic compounds, reduced the proteolytic activity of Arginin-specific gingipain (IC50 12.78 µg/mL). Fractions EAF and FLB7, characterized by lipohilic constituents, inhibited Arg-gingipain (IC50 3 µg/mL). On Lysine-specific gingipain, AQF has an IC50 15.89, EAF 14.15, and FLB7 6 µg/mL. The reduced bacterial adhesion is due to a strong interaction of proanthocyanidins with gingipains. AQF, EAF, and FLB7 significantly inhibited biofilm formation: IC50 11.34 (AQF), 11.66 (EAF), and 12.09 µg/mL (FLB7). In silico analysis indicated, that the polyphenols act against specific targets of Pg, not affecting mammalian cells. Therefore, Lb might be effective for prevention of periodontal disease by influencing virulence factors of Pg.

Isolation and biological activity of six new polyketide and terpenoid derivatives from Neopestalotiopsis Clavispora AL01.

A fungus strain, Neopestalotiopsis clavispora AL01, was isolated from the leaf spot of the plant Phoenix dactylifera. Further chemical investigation of the fermentation extract of this strain afforded six new secondary metabolites (1-6), along with 11 known compounds (7-17) which included a new natural compound (7). Their structures were determined by extensive spectroscopic analysis including one-and two-dimensional (1D and 2D) NMR spectroscopy, high-resolution electrospray ionization mass spectrometry (HRESIMS), and ECD and NMR calculations. All compounds were evaluated for their phytotoxic activities. Among them, compounds 10, 12 and 13 exhibited phytotoxic activities against Nicotiana tabacum. Compound 3 exhibited weak antibacterial activity against methicillin-resistant Staphylococcus aureus, Micrococcus luteus and Vibrio harveyi. Taken collectively, these findings establish a solid research foundation for future investigations on bioactive natural products derived from phytopathogenic fungi.

Structure, anti-inflammatory and anti-bacterial activities of novel pentacyclic triterpenoids and other constituents from the leaves of Pittosporum elevaticostatum.

The investigation of the leaves of Pittosporum elevaticostatum Chang et Yan led to the isolation of fifteen pentacyclic triterpenoids (1-15), including five previously undescribed ones (1-5), and nine others (16-24). The structures of compounds 1-5 were elucidated based on comprehensive spectroscopic techniques, including one dimension (1D) and 2D nuclear magnetic resonance (NMR), high resolution electrospray ionization mass spectroscopy (HR-ESI-MS), and other methods. Compounds 2 and 13 demonstrated significant inhibitory activity against Listeria monocytogenes (L. monocytogenes) with minimum inhibitory concentration (MIC) values of 32 µM. Scanning electron microscopy (SEM) observations revealed insights into the antibacterial mechanism, indicating that compounds 2 and 13 either prevent biofilm formation of dispersed the preformed cell membranes. Additionally, compounds 1, 5, 7, and 12 exhibited anti-inflammatory activity on lipopolysaccharide (LPS)-stimulated BV-2 microglial cells with IC50 values ranging from 11.27 to 17.80 µM.

Antimicrobial isoflavans and other metabolites of Dalea nana.

The phytochemical investigation of extracts from Dalea nana roots and aerial parts led to the isolation of thirteen phenolic compounds. Three previously undescribed isoflavans, named verdeans A-C (1, 3, and 7), were characterized. Two additional isoflavans (2 and 5) were previously undescribed enantiomers of known compounds. A previously undescribed isoflavone (verdean D, 10) was found, and the known specialized metabolites, isoflavans 4, 6, 8, and 9, isoflavone 11, flavone 12, and a 2-arylbenzofuran 13, were also isolated. All but one (7) of the isoflavans were prenylated. The structures of the previously undescribed compounds were deduced by NMR spectroscopy, supported by HRESI mass spectrometry. The absolute configurations of 1-3, 5, and 7-9 were determined by ECD. Compounds 1, 3, 4, 6, and 8 exhibited in vitro antimicrobial activities, causing complete growth inhibition (MIC) at concentrations between 6.7 and 37.0 µM against Cryptococcus neoformans and between 8.9 and 25.0 µM against methicillin resistant Staphylococcus aureus (MRSA). The most broadly active previously undescribed compound was verdean A (1), with MIC values of 6.7 and 12.9 µM toward C. neoformans and MRSA, respectively, and an MIC of 10.0 µM against the often-intractable C. albicans.

Preparation and Selective Adsorption Performance of the Carboxymethyl Salix psammophila Wood Powder-Imprinted Membrane for Tetracycline.

Carboxymethyl Salix psammophila wood powder-imprinted membranes (CMSM-MIPs) were prepared by using wet spinning technology and molecular-imprinting technology for the selective removal of tetracycline from wastewater. Scanning electron microscopy, X-ray diffraction, thermogravimetry, and X-ray photoelectron spectroscopy characterizations demonstrate that CMSM-MIPs retain the membranous structure of Carboxymethyl Salix psammophila wood powder membranes, successfully encapsulate thin layers of imprinted polymers on the membrane surface, and exhibit excellent thermal stability. The adsorption results showed that CMSM-MIPs had the highest selective adsorption capacity for tetracycline, which was 253.8 mg/g. In addition, the adsorption capacities for oxytetracycline and chlortetracycline were 208.8 and 188 mg/g, respectively. It can be observed that CMSM-MIPs not only exhibit a high adsorption capacity for tetracycline but also demonstrate good adsorption capacities for oxytetracycline and chlortetracycline. The experimental results showed that CMSM-MIPs were best fitted with pseudo-second-order kinetics and most consistent with Freundlich fitting. The regeneration experiment showed that CMSM-MIPs still had good regeneration performance after 5 regeneration cycles. In conclusion, the CMSM-MIPs can not only have the natural adsorption performance of Salix psammophila wood powder but also give it higher selectivity through molecular imprinting, so as to achieve efficient removal of target organic pollutants in water.

Abietane diterpenoids from Isodon amethystoides and their biological activities.

Seven undescribed abietane diterpenoids [abietamethinols A-G (1-7)] were isolated from the twigs and leaves of Isodon amethystoides. Their structures were elucidated on the basis of spectroscopic methods including 2D NMR, and they were further confirmed by X-ray crystallographic data. Lophanic acid was considered as the precursor of 1-7 in the biosynthesis pathway hypothesis. These compounds were evaluated for their cytotoxic, anti-bacterial and anti-AIV (avian influenza virus) activities. Compound 5 showed 42.9% inhibitory activity against the cancer cell line SMMC-7721 at the concentration of 40 µM, 3 and 4 could inhibit the bacterial growth of Streptococcus sobrinus by 55.3% and 63.2% at the concentrations of 148.6 and 141.9 µM, respectively, and 4 was demonstrated with antiviral activity against AIV with the inhibitory effect of 68.4% at 25 µM.