To investigate the non-alkaloidal chemical constituents of the stems and leaves of Melodinus suaveolens and their antibacterial activities. Compounds were isolated and purified by repeated silica gel, Sephadex LH-20, RP18, and preparative HPLC. Their structures were elucidated by comparison with published spectroscopic data, as well as on the basis of extensive spectroscopic analysis. The antibacterial screening assays were performed by the dilution method. Fourteen compounds were isolated, and identified as lycopersene (1), betulinic aldehyde (2), 3β-acetoxy-22,23,24,25,26,27-hexanordammaran-20-one (3), 3a-acetyl-2, 3, 5-trimethyl-7a-hydroxy-5-(4,8,12-trimethyl-tridecanyl)-1,3a,5,6,7,7a-hexahydro-4-oxainden-1-one (4), 3β-hydroxy-28-norlup-20(29)-ene-17β-hydroperoxide (5), 3β-hydroxy-28-norlup-20(29)-ene-17α-hydroperoxide (6), β-sitosterol (7), 28-nor-urs-12-ene-3β, 17β-diol (8), α-amyrin (9), ergosta-4,6,8(14),22-tetraen-3-one (10), 3β-hydroxy-urs-11-en-28,13β-olide (11), betulin (12), obtusalin (13), and ursolic acid (14). Among the isolates, compounds 1, 2, 6, 8, 10, and 14 showed potent antibacterial activities against the four bacteria. This is the first report of the antibacterial activity of the constituents of Melodinus suaveolens.
Anti-Bacterial Agents ; chemistry ; Apocynaceae ; chemistry ; Drugs, Chinese Herbal ; chemistry ; Plant Leaves ; chemistry ; Plant Stems ; chemistry

OBJECTIVE: To characterize the silver in chitosan antibacterial gel, and to establish a method for the determination of silver content in samples. METHODS: The silver in the samples was analysed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and single particle inductively coupled plasma mass spectrometry (SP-ICP-MS). Microwave digestion was adopted to digest the chitosan antibacterial gel, and then the content of silver was determined by flame atomic absorption spectrometry. RESULTS: The analysises showed that the particle size of silver in chitosan antibacterial gel was about 150~ 200 nm. The silver showed good linearity in the concentration range of 25~250 μg/L (y=0.000 35x+0.001 7, r=0.999 9). The recovery rate (n=9) was 98.5%. CONCLUSIONS SEM, EDS and SP-ICP-MS can be used for the characterization of silver particles in chitosan antibacterial gel. Microwave digestion-flame atomic absorption spectrophotometry method is simple, practicable, high precision and high quantitative accuracy, which is suitable for the quantitative analysis of silver in chitosan antibacterial gel.
Anti-Bacterial Agents/pharmacology* ; Chitosan/chemistry* ; Microwaves ; Particle Size ; Silver

The genus Carpesium plants contain many kinds of sesquiterpenes. Up to now, more than 201 sesquiterpene compounds have been isolated and identified, including 86 germacranolides, 30 eudesmanolides, 29 guaianolides, 23 sesquiterpene dimers, 9 pseudoguaianes, 9 carabranolides, 7 xanthanolides, 6 sesquiterpenes without lactone, 1 eremophilane and 1 tricyclo dodecane sesquiterpene. The reported sesquiterpenes possess a series of pharmacological properties, such as anti-tumor, anti-inflammatory, antibacterial, antiparasitic, insecticidal, and antiviral activities. This paper summarizes the 201 chemical structures and biological activities of sesquiterpenes in genus Carpesium, and provides the scientific basis for the further development and utilization.
Anti-Bacterial Agents ; Anti-Inflammatory Agents ; Asteraceae/chemistry* ; Lactones ; Molecular Structure ; Phytochemicals/pharmacology* ; Sesquiterpenes/pharmacology*

Antimicrobial peptides (AMPs) are a class of peptides widely existing in nature with broad-spectrum antimicrobial activity. It is considered as a new alternative to traditional antibiotics because of its unique mechanism of antimicrobial activity. The development and application of natural AMPs are limited due to their drawbacks such as low antimicrobial activity and unstable metabolism. Therefore, the design and optimization of derived peptides based on natural antimicrobial peptides have become recent research hotspots. In this paper, we focus on ribosomal AMPs and summarize the design and optimization strategies of some related derived peptides, which include reasonable primary structure modification, cyclization strategy and computer-aided strategy. We expect to provide ideas for the design and optimization of antimicrobial peptides and the development of anti-infective drugs through analysis and summary in this paper.
Antimicrobial Cationic Peptides/chemistry* ; Antimicrobial Peptides ; Drug Design ; Anti-Infective Agents/pharmacology* ; Anti-Bacterial Agents

BACKGROUNDIntracranial infection is one of the most common complications of open craniocerebral injury and of conventional craniotomy in neurosurgery. The presence of blood-brain barrier leads to lower drug concentrations in the cerebrospinal fluid than in the venous blood. Increasing the intravenous dosage or frequency carries the risk of systemic adverse reactions or infections in other parts of the body. Developing an artificial dura mater (ADM) for sustained antibiotic release for use during neurosurgery can solve the problems perfectly.

METHODSThree types of drug-loaded ADMs made of collagen and containing cefuroxime sodium, ceftriaxone sodium, or norvancomycin were prepared. The antibacterial activity and sustained release characteristics of the ADMs were examined using bacteriostatic and release tests.

RESULTSSingle-layered collagen based ADMs (40 mm×50 mm×5 mm) containing 18 mg cefuroxime sodium or ceftriaxone sodium were not suitable for continued development because of drug preservation and stability issues. Using smaller ADMs (20 mm×30 mm×7 mm), containing 4.86 mg of norvancomycin, with increased collagen density and a three-layered film with two outer drug-free films above and below the antibiotic layer resulted in sustained cumulative release of 2.91 mg (59.9%) of norvancomycin over 72 hours. The similar factor (f2) comparison method proved that products from a same batch were statistically significant similar (f2 > 50).

CONCLUSIONSArtificial ADMs made of collagen can be processed to provide a mature dural repair material for the sustained release of norvancomycin. This system may provide a basis for developing sustained release materials for other drugs.

Anti-Bacterial Agents ; chemistry ; Biocompatible Materials ; chemistry ; Ceftriaxone ; chemistry ; Cefuroxime ; chemistry ; Collagen ; chemistry ; Dura Mater ; chemistry ; Vancomycin ; analogs & derivatives ; chemistry

According to documents of recent fifty years the article summarized the herbalogical study, processing, chemical constituent, quality standard, pharmacologic action and clinical study of Oroxylum indicum. The chemical constituents mainly are flavonoids, glycoside and volatile oil. It also contains pterocarpan and rhodioside with p-hydroxyphenylethanols and cyclohexanols. Quantitative index was added in the quality standard of china pharmacopeia since 1995, but the quantitative standard is blank at the present, and the baicalin was mostly used for quantitative standard in the documents which lack of mark. Baicalein -7-O-diglucoside didn't existed in the other plants. It's mark will do good to the enhancement of quality standard. Pharmacologic action and clinical study were mainly anti-inflammatory, anti-mutagenesis, antibiosis, anticancera,and coughing.
Animals ; Anti-Bacterial Agents ; chemistry ; pharmacology ; Anti-Inflammatory Agents ; chemistry ; pharmacology ; Antineoplastic Agents, Phytogenic ; chemistry ; pharmacology ; Bignoniaceae ; chemistry ; Humans ; Molecular Structure ; Plant Extracts ; chemistry ; pharmacology ; Plants, Medicinal ; chemistry

Chuangxinmycin (CM) from Actinoplanes tsinanensis was an antibiotic discovered by Chinese scientists about 40 years ago. It contains a new heterocyclic system of indole fused with dihydrothiopyran, whose biosynthetic mechanism remains unclear. CM is used as an oral medicine in the treatment of bacterial infections in China. The simple structure makes CM as an attractive candidate of structure modification for improvement of antibacterial activity. Recently, we analyzed the secondary metabolites of Actinoplanes tsinanensis CPCC 200056, a CM producing strain, as a natural CM analogue. We discovered the first natural CM analogue 3-demethylchuangxinmycin (DCM) as a new natural product. Compared to CM, DCM exhibited a much weaker activity in the inhibition of the bacterial strains tested. The finding provides valuable information for the structure-activity relationship in the biosynthesis of CM.
Anti-Bacterial Agents ; chemistry ; isolation & purification ; China ; Indoles ; chemistry ; isolation & purification ; Micromonosporaceae ; chemistry ; Structure-Activity Relationship

Anti-Bacterial Agents ; chemical synthesis ; chemistry ; Combinatorial Chemistry Techniques ; Diketopiperazines ; Molecular Structure ; Piperazines ; chemical synthesis ; chemistry

The chiral recognition site of the macrocyclic antibiotic vancomycin, used as a chiral selector in capillary electrophoresis (CE), was studied with ofloxacin, antofloxacin (a new fluoroquinolone antibiotic under development) and R-antofloxacin, as well as with norvancomycin. Enantioselectivity of vancomycin and norvancomycin was compared. The influence of vancomycin concentration, pH of buffer, and separation voltage in CE were examined in order to investigate interactions between enantiomers and vancomycin. Furthermore, interactions of chiral selectors and enantiomers were calculated by molecular mechanics method with Chem 3D software. The result indicates that both vancomycin and norvancomycin have two domains in 3D structure, and the domain I of vancomycin was considered to be the chiral recognition site of ofloxacin. The degree of interaction between vancomycin and ofloxacin is determined as follows: hydrogen bond occurring with carboxylic group at C-6 of ofloxacin and hydroxyl group of sugar part of vancomycin, the matching degree of molecular sizes of ofloxacin with the pocket in domain I of vancomycin and the hydrophobic interaction between methyl group at C-10 of piperidine group of ofloxacin and N-methyl leucine of vancomycin.
Anti-Bacterial Agents ; chemistry ; Electrophoresis, Capillary ; methods ; Ofloxacin ; chemistry ; Stereoisomerism ; Vancomycin ; analogs & derivatives ; chemistry

Antibiotics are playing an increasingly important role in clinical antibacterial applications. However, their abuse has also brought toxic and side effects, drug-resistant pathogens, decreased immunity and other problems. New antibacterial schemes in clinic are urgently needed. In recent years, nano-metals and their oxides have attracted wide attention due to their broad-spectrum antibacterial activity. Nano-silver, nano-copper, nano-zinc and their oxides are gradually applied in biomedical field. In this study, the classification and basic properties of nano-metallic materials such as conductivity, superplasticity, catalysis, and antibacterial activities were firstly introduced. Secondly, the common preparation techniques, including physical, chemical and biological methods, were summarized. Subsequently, four main antibacterial mechanisms, such as cell membrane, oxidative stress, DNA destruction and cell respiration reduction, were summarized. Finally, the effect of size, shape, concentration and surface chemical characteristics of nano-metals and their oxides on antibacterial effectiveness and the research status of biological safety such as cytotoxicity, genotoxicity and reproductive toxicity were reviewed. At present, although nano-metals and their oxides have been applied in medical antibacterial, cancer treatment and other clinical fields, some issues such as the development of green preparation technology, the understanding of antibacterial mechanism, the improvement of biosafety, and the expansion of application fields, require further exploration.
Oxides/chemistry* ; Metal Nanoparticles/chemistry* ; Anti-Bacterial Agents/chemistry* ; Zinc ; Copper