Natural collagen peptides are collagen hydrolysates. Because of their unique physicochemical properties and excellent biological activities, collagen peptides have been a research hotspot of cosmetic raw materials development and skincare efficacy improvement. Combined with the needs of the skincare efficacy and the development trends of cosmetics, the extraction methods and their structural characteristics of natural collagen peptides were summarized in detail. The applications and its research progress in skincare efficacy of collagen peptides, such as moisturizing and anti-wrinkle, trophism and anti-aging, filling and skin regeneration were expressed with emphasis. Finally, the development and practical applications in cosmetics of natural collagen peptides were adequately prospected.
Skin Care ; Skin ; Peptides/pharmacology* ; Cosmetics/chemistry* ; Collagen

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

OBJECTIVETo observe the binding power of polymyxin B (PMB) and its simulation peptide to lipopolysaccharide (LPS) and lipoid A.

METHODSLPS and lipoid A were separately coated on biosensor. 5 microl of PMB (0.01 microg/L) 5 microl of its simulating peptide 1 (PMBSP1 0.01 microg/L) and 5 microl of its simulating peptide 2 (PMBSP2, 0.01 microg/L) were respectively added into the hydrophobic sample pool. The combining power of PMB and its simulating peptides PMBSP1 and PMBSP2 to LPS and lipoid A was compared. RESULTS (1) PMBSP1 almost did not bind LPS and lipoid A, while PMB and PMBSP2 possessed high affinity with LPS and lipoid A. (2) The peak value (98.41 +/- 7.31) rad/s of PMBSP2 binding LPS was much higher than that (83.58 +/- 5.42) rad/s of PMB in binding LPS (P < 0.05). While the peak value of PMB in binding lipoid A was similar to that of PMBSP2. (3) The peak value of PMB binding LPS was significantly lower than that of PMB in binding lipoid A (P < 0.05). But there was no difference between the peak value of PMBSP2 in binding LPS and that of PMBSP2 in binding lipoid A. (4) PMBSP2 could bind to LPS and lipoid A in a shorter time to reach peak levels.

CONCLUSIONCompared with PMB, the PMBSP2 could bind to LPS and lipoid A in a shorter time. In addition, PMBSP2 exhibited similar affinity to LPS and lipoid A. This indicated that PMBSP might possess better anti-LPS activity due to its lack of space steric hindrance when PMBSP binding the lipoid A of LPS.

Cell Wall ; chemistry ; Endotoxins ; Gram-Negative Bacteria ; Lipopolysaccharides ; chemistry ; toxicity ; Peptides ; chemistry ; pharmacology ; Polymyxin B ; chemistry ; pharmacology

As the technologies of separation, purification and determination develop rapidly, more and more peptide compounds, which have special bioactive and medical value, have been separated from natural plants, such as oligopeptides and cyclopeptides. The chemical structures and function of these plant peptides have been researched profoundly. This paper mainly reviews the composition, structure, bioactive function and medicine value of representative plant peptides in recent years, and can give some references about research and application of plant bioactive peptides.
Animals ; Antihypertensive Agents ; chemistry ; isolation & purification ; pharmacology ; Antineoplastic Agents, Phytogenic ; chemistry ; isolation & purification ; pharmacology ; Antioxidants ; chemistry ; isolation & purification ; pharmacology ; Glutathione ; chemistry ; isolation & purification ; pharmacology ; Gramicidin ; chemistry ; isolation & purification ; pharmacology ; Humans ; Hypoglycemic Agents ; chemistry ; isolation & purification ; pharmacology ; Oligopeptides ; chemistry ; isolation & purification ; pharmacology ; Peptides ; chemistry ; isolation & purification ; pharmacology ; Peptides, Cyclic ; chemistry ; isolation & purification ; pharmacology ; Plants ; chemistry ; Plants, Medicinal ; chemistry

The study was aimed to investigate the possibility of enhancing transfection efficiency of branched polyethylenimine (BPEI) in HeLa cells by hydrophobic tail of bee venom peptide (melittin). Hydrophobic tail of melittin was synthesized and its membrane permeable activity was evaluated by hemolysis test. The peptide was mixed with BPEI and the transfection efficiency was determined in HeLa cells by using green fluorescent protein gene (GFP) as a reporter gene. The cytotoxicity of the mixture was analyzed by MTT assay at 24 hours after transfection. The results indicated that the synthesized peptide had permeable activity leading to hemolysis in both neutral and acidic solution. At optimal condition, the peptide could significantly improve the transfection efficiency of BPEI and the cytotoxicity of the mixture was lower than BPEI itself. It is concluded that hydrophobic tail of melittin may be a potential enhancer to improve transfection efficiency mediated by cationic polymers in difficult to transfect cells.
HeLa Cells ; Humans ; Hydrophobic and Hydrophilic Interactions ; Melitten ; chemistry ; genetics ; Peptides ; chemistry ; Polyethyleneimine ; pharmacology ; Transfection

Four cyclic peptides were isolated from the 75% ethanol extract of the fibrous roots of Pseudostellaria heterophylla by silica gel, Sephadex LH-20 column chromatography, and semi-preparative HPLC. Through mass spectrometry, NMR and other methods, they were identified as pseudostellarin L(1), heterophyllin B(2), pseudostellarin B(3), and pseudostellarin C(4). Among them, compound 1 was a new cyclic peptide, and compounds 2-4 were isolated from the fibrous roots of P. heterophylla for the first time. None of these compounds displayed cytotoxic activities against MCF-7, A549, HCT-116, and SGC-7901 cells.
Caryophyllaceae/chemistry* ; Chromatography, High Pressure Liquid ; Magnetic Resonance Spectroscopy ; Peptides, Cyclic/pharmacology* ; Plant Roots/chemistry*

OBJECTIVEA natural cyclic peptide previously isolated from Citrus medica was synthesized by coupling of tetrapeptide units Boc-Leu-Pro-Trp-Leu-OMe and Boc-Ile-Ala-Ala-Gly-OMe after proper deprotection at carboxyl and amino terminals followed by cyclization of linear octapeptide segment.

METHODSSolution phase technique was adopted for the synthesis of cyclooctapeptide-sarcodactylamide. Required tetrapeptide units were prepared by coupling of Boc-protected dipeptides viz. Boc-Leu-Pro-OH and Boc-Ile-Ala-OH with respective dipeptide methyl esters Trp-Leu-OMe and Ala-Gly-OMe. Cyclization of linear octapeptide unit was done by p-nitrophenyl ester method. The structure of synthesized cyclopolypeptide was elucidated by FTIR, 1H NMR, 13C NMR, FABMS spectral data and elemental analysis. The newly synthesized peptide was evaluated for different pharmacological activities including antimicrobial, anthelmintic and cytotoxic activities.

RESULTSSynthesis of sarcodactylamide was accomplished with >78% yield utilizing dicyclohexylcarbodiimide (DCC) as coupling agent. Newly synthesized peptide possessed potent cytotoxic activity against Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines, in addition to moderate anthelmintic activity against earthworms Megascoplex konkanensis, Pontoscotex corethruses and Eudrilus sp. Moreover, cyclopolypeptide displayed good antimicrobial activity against pathogenic fungi Candida albicans and Gram-negative bacteria Pseudomonas aeruginosa, in comparison to standard drugs griseofulvin and ciprofloxacin.

CONCLUSIONSolution phase technique employing DCC and triethylamine (TEA) as base proved to be effective for the synthesis of natural cyclooctapeptide. N-methyl morpholine (NMM) was found to be a better base for the cyclization of linear octapeptide unit in comparison to TEA and pyridine.

Animals ; Anti-Infective Agents ; chemical synthesis ; pharmacology ; Antineoplastic Agents ; chemical synthesis ; pharmacology ; Citrus ; chemistry ; Mice ; Peptides, Cyclic ; chemical synthesis ; pharmacology

Ocean is a unique and excellent resource that provides a diverse array of intriguing natural products. Marine natural products have demonstrated significant and extremely potent biological activities and have captured the attention of natural products chemists in the past few decades. It is increasingly recognized that a wealth of fascinating natural products and novel chemical entities will play a dominant role in the discovery of useful leads for the development of pharmaceutical agents and provide useful probes to lead to breakthroughs in a variety of life-science fields. This article focused on the research progress of chemistry of marine natural products in recent five years.
Alkaloids ; chemistry ; isolation & purification ; pharmacology ; Animals ; Anti-Infective Agents ; chemistry ; isolation & purification ; pharmacology ; Antineoplastic Agents ; chemistry ; isolation & purification ; pharmacology ; Aquatic Organisms ; chemistry ; Biological Products ; chemistry ; isolation & purification ; pharmacology ; Humans ; Macrolides ; chemistry ; isolation & purification ; pharmacology ; Marine Biology ; Marine Toxins ; chemistry ; isolation & purification ; pharmacology ; Molecular Structure ; Peptides ; chemistry ; isolation & purification ; pharmacology ; Steroids ; chemistry ; isolation & purification ; pharmacology ; Terpenes ; chemistry ; isolation & purification ; pharmacology

Cyclic lipopeptide, also named as acylpeptide, which was characteristic with novel structures, was paid more attention in the recent years. Cyclic lipopeptide showed various bioactivities including antibacterial, anti-tumor, anti-inflammatory, etc. Cyclic lipopeptide originated mainly from the second metabolites of microorganism, such as Cyanobacterium, Bacterium, Actinomyces, etc. The bacteria included the genus of Bacillus and Pseudomonas. In this account, the review has been made on the development of cyclic lipopeptide.
Anti-Bacterial Agents ; pharmacology ; Antibiotics, Antineoplastic ; pharmacology ; Bacillus ; chemistry ; Cyanobacteria ; chemistry ; Daptomycin ; isolation & purification ; pharmacology ; Humans ; Lipopeptides ; chemistry ; isolation & purification ; pharmacology ; Peptides, Cyclic ; chemistry ; isolation & purification ; pharmacology ; Pseudomonas ; chemistry

OBJECTIVETo determine the relative molecular mass of marine collagen peptides (MCPs) and investigate the effects of MCPs on serum lipids, anti-oxidative enzymes and malondialdehyde (MDA) in hyperlipidemic rats.

METHODSSephadex G-25, high performance liquid chromatography (HPLC) and matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS) methods were used to determine the relative molecular mass of MCPs. Then 50 healthy male SD rats were divided into 5 groups, which were normal control (NC) group, hyperlipidemic model control (HC) group and 1.0, 3.0, 9.0 g/kgbw MCPs groups, MCPs were orally administered by gavage to rats in MCPs group for 45 consecutive days (2 ml/100 kgbw per day), and the control rats were given vehicle only, all animals (except NC rats) were fed with a high fat diet composed of 79% basic diet, 10% lard, 10% yolk powder and 1% cholesterol. The levels of serum lipids, the content of MDA and activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) in serum were measured.

RESULTSThe levels of serum total cholesterol (TC) in 1.0, 3.0, 9.0 g/kgbw MCPs groups were 1.89 +/- 0.29, 2.07 +/- 0.39 and 1.99 +/- 0.29 mmol/L respectively, each of which was significantly lower than that in HC group (3.37 +/- 0.24 mmol/L); low-density lipoprotein cholesterol (LDL-C) levels in 1.0, 3.0, 9.0 g/kgbw MCPs groups were 0.83 +/- 0.16, 1.01 +/- 0.35 and 0.91 +/- 0.26 mmol/L respectively, each of which was significantly lower than that in HC group(2.20 +/- 0.34 mmol/L); triglyceride (TG) levels in 3.0 and 9.0 g/kgbw MCPs groups (0.90 +/- 0.15 and 0.86 +/- 0.12 mmol/L) were reduced significantly compared with that in HC group (1.18 +/- 0.18 mmol/L); MDA level in 9.0 g/kgbw MCPs group was 7.1 +/- 4.1 nmol/ml, which was significantly lower than that in HC group ( 15.9 +/- 9.9 nmol/ml); and atherogenic index (AI) in hyperlipidemic rats fed with 1.0, 3.0, 9.0 g/kgbw MCPs were 1.14 +/- 0.22, 1.16 +/- 0.27 and 0.99 +/- 0.31 respectively, each of which was significantly lower than that in HC group (2.27 +/- 0.55). The activities of SOD in 1.0, 3.0, 9.0 g/kgbw MCPs groups (218.6 +/- 33.2, 242.7 +/- 21.4 and 242.1 +/- 44.8 U/ml) were obviously increased compared with that in HC group (119.7 +/- 47.8 U/ml), and anti-atherogenic index (AAI) were also increased significantly (0.47 +/- 0.04, 0.47 +/- 0.06, 0.51 +/- 0.09 vs 0.31 +/- 0.05).

CONCLUSIONMCPs should have antioxidative and lipid-lowering effects, and might play a preventive role in hyperlipidemia and atherogenesis.

Animals ; Antioxidants ; pharmacology ; Cholesterol ; blood ; Cholesterol, LDL ; blood ; Collagen ; chemistry ; pharmacology ; Hypolipidemic Agents ; pharmacology ; Male ; Marine Biology ; Peptides ; chemistry ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; blood