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

Lawsonia inermis is a single-species genus of the Lythraceae family, its leaves, stem bark, roots, flowers and seeds have been used in traditional medicine. It has been paid more attention by scholars from many countries because of their various types of compounds and significant physiological activities. The plant is reported to contain quinones, phenylpropanoids, flavonoids, terpenoids, phenolic compounds and fatty acids. Modern pharmacological studies have demonstrated that the plant performs antimicrobial, antioxidant, anticancer and antiparasitic activity. This article mainly summarizes the research advances of chemical constituents and biological activities of Lawsonia inermis, for its further development and utilization.
Anti-Infective Agents ; chemistry ; pharmacology ; Antineoplastic Agents ; chemistry ; pharmacology ; Antioxidants ; chemistry ; pharmacology ; Antiparasitic Agents ; chemistry ; pharmacology ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; Humans ; Lawsonia Plant ; chemistry

Andrographolide (AG) is a main effective ingredient in leaves of Andrographis paniculata. AG and its derivatives have such effects in anti-infection, anti-tumor and immuno-regulation. Particularly, its antibacterial, antiviral and anti-protozoal activities play an increasingly important role in resisting opportunistic infections. On the basis of our studies on AG over the years, we made a summary for the basis and clinical studies on AG and its derivatives over the past 10 years.
Andrographis ; chemistry ; Animals ; Anti-Infective Agents ; chemistry ; pharmacology ; Diterpenes ; chemistry ; pharmacology ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; Humans ; Structure-Activity Relationship

Mangroves are salt-tolerant forest ecosystem that extends between tropical and subtropical intertidal regions of the world. Mangroves are biochemically unique vegetation that produce wide array of natural products with immense medicinal potential. These plants are the most valuable resources and provide economic and ecological benefits to the coastal people. Natural products from these plants are of great interest as they provide innumerable direct and indirect benefits to human beings for the discovery of novel antimicrobial and other bioactive compounds. They possess active metabolites with some novel chemical structures that belong to diverse chemical classes such as alkaloids, phenol, steroids, terpenoids and tannins. Several mangrove species have been used in traditional medicine or have few applications as insecticide and pesticide. To date, several mangroves, and their associated species and solvent extracts are screened for antimicrobial activity along with the presence of potent bioactive compounds. The present article emphasizes and creates awareness about the potential mangrove plants and their associates as a source of biologically active compounds with potent antimicrobial properties. This paper also elaborates the mechanisms of action and various methods for screening of antimicrobial compounds.
Anti-Infective Agents ; isolation & purification ; pharmacology ; Avicennia ; chemistry ; Ecosystem ; Plant Extracts ; isolation & purification ; pharmacology

The aim of this review was to explore the pharmacological activity of early tracheophytes (pteridophytes) as an alternative medicine for treating human ailments. As the first vascular plants, pteridophytes (aka, ferns and fern allies) are an ancient lineage, and human beings have been exploring and using taxa from this lineage for over 2000 years because of their beneficial properties. We have documented the medicinal uses of pteridophytes belonging to thirty different families. The lycophyte Selaginella sp. was shown in earlier studies to have multiple pharmacological activity, such as antioxidant, anti-inflammatory, anti-cancer, antidiabetic, antiviral, antimicrobial, and anti-Alzheimer properties. Among all the pteridophytes examined, taxa from the Pteridaceae, Polypodiaceae, and Adiantaceae exhibited significant medicinal activity. Based on our review, many pteridophytes have properties that could be used in alternative medicine for treatment of various human illnesses. Biotechnological tools can be used to preserve and even improve their bioactive molecules for the preparation of medicines against illness. Even though several studies have reported medicinal uses of ferns, the possible bioactive compounds of several pteridophytes have not been identified. Furthermore, their optimal dosage level and treatment strategies still need to be determined. Finally, the future direction of pteridophyte research is discussed.
Anti-Infective Agents/pharmacology* ; Anti-Inflammatory Agents/pharmacology* ; Antineoplastic Agents, Phytogenic/pharmacology* ; Antioxidants/pharmacology* ; Humans ; Phytochemicals/pharmacology* ; Phytotherapy ; Plant Extracts/pharmacology* ; Tracheophyta/chemistry*

The genus Ephedra of the Ephedraceae family contains more than 60 species of nonflowering seed plants distributed throughout Asia, America, Europe, and North Africa. These Ephedra species have medicinal, ecological, and economic value. This review aims to summarize the chemical constituents and pharmacological activities of the Ephedra species to unveil opportunities for future research. Comprehensive information on the Ephedra species was collected by electronic search (e.g., GoogleScholar, Pubmed, SciFinder, and Web of Science) and phytochemical books. The chemical compounds isolated from the Ephedra species include alkaloids, flavonoids, tannins, polysaccharides, and others. The in vitro and in vivo pharmacological studies on the crude extracts, fractions and few isolated compounds of Ephedra species showed anti-inflammatory, anticancer, antibacterial, antioxidant, hepatoprotective, anti-obesity, antiviral, and diuretic activities. After chemical and pharmacological profiling, current research is focused on the antibacterial and antifungal effects of the phenolic acid compounds, the immunosuppressive activity of the polysaccharides, and the antitumor activity of flavonoids.
Animals ; Anti-Infective Agents ; chemistry ; pharmacology ; Antioxidants ; chemistry ; pharmacology ; Antiviral Agents ; chemistry ; pharmacology ; Drugs, Chinese Herbal ; chemistry ; pharmacology ; Ephedra ; chemistry ; Humans

Aegle marmelos Linn. (Rutaceae), commonly known as "bael" in Nepal and India, is a valuable medicinal plant and is considered sacred by the Hindus. It is used to cure several diseases in the Indian traditional medicine system of Ayurveda and has had similar uses among many ethnic communities residing in Indian subcontinent for over 5000 years. Its leaves, bark, stem, fruits and seeds have been used for various medicinal purposes. Bael fruits are especially effective in the treatment of chronic diarrhea, dysentery and peptic ulcers, while they are also useful as a laxative and cure for respiratory infections. Scientific studies have validated many of the ethnomedicinal uses of A. marmelos, which include antibacterial, antiviral, antidiarrheal, gastroprotective, anti-ulcerative colitis, hepatoprotective, antidiabetic, cardioprotective and radioprotective effects. Recently, this plant has also received attention as an anticancer agent for the treatment of various types of cancers. Thus, this review focuses on scientific evidence verifying the important pharmacological activity such as antioxidant, antidiabetic, antimicrobial, hepatoprotective, cardioprotective and anticancer activity of A. marmelos.
Aegle ; chemistry ; Animals ; Anti-Infective Agents ; chemistry ; pharmacology ; Antioxidants ; chemistry ; pharmacology ; Humans ; Phytochemicals ; chemistry ; pharmacology ; Plant Extracts ; chemistry ; pharmacology ; Plants, Medicinal ; chemistry

The ocean continues to provide a plethora of unique scaffolds capable of remarkable biological applications. A large number of pyrroloiminoquinone alkaloids, including discorhabdins, epinardins, batzellines, makaluvamines, and veiutamine, have been isolated from various marine organisms. A class of pyrroloiminoquinone-related alkaloids, known as bispyrroloquinones, is the focus of this review article. This family of marine alkaloids, which contain an aryl substituted bispyrroloquinone ring system, includes three subclasses of alkaloids namely, wakayin, tsitsikammamines A-B, and zyzzyanones A-D. Both wakayin and the tsitsikammamines contain a tetracyclic fused bispyrroloiminoquinone ring system, while zyzzyanones contain a fused tricyclic bispyrroloquinone ring system. The unique chemical structures of these marine natural products and their diverse biological properties, including antifungal and antimicrobial activity, as well as the potent, albeit generally nonspecific and universal cytotoxicities, have attracted great interest of synthetic chemists over the past three decades. Tsitsikammamines, wakayin, and several of their analogs show inhibition of topoisomerases. One additional possible mechanism of anticancer activity of tsitsikammamines analogs that has been discovered recently is through the inhibition of indoleamine 2, 3-dioxygenase, an enzyme involved in tumoral immune resistance. This review discusses the isolation, synthesis, and evaluation of bioactivities of bispyrroloquinone alkaloids and their analogs.
Alkaloids ; chemistry ; pharmacology ; Animals ; Anti-Infective Agents ; chemistry ; pharmacology ; Antineoplastic Agents ; chemistry ; pharmacology ; Biological Products ; chemistry ; pharmacology ; Humans ; Indole Alkaloids ; chemistry ; pharmacology ; Indoles ; chemistry ; pharmacology ; Pyrroles ; chemistry ; pharmacology ; Quinolines ; chemistry ; pharmacology ; Quinones ; chemistry ; pharmacology

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

Licochalcone A (LCA), as a major flavonoid in Glycyrrhiza inflate, has attracted wide attention in recent years. Studies showed that LCA has multiple pharmacological effects such as anti-tumour, anti-inflammation, anti-bacteria and anti-parasite. We made a summary for domestic and foreign study literatures for various pharmacological effects of LCA.
Animals ; Anti-Infective Agents ; pharmacology ; Anti-Inflammatory Agents ; pharmacology ; Antineoplastic Agents, Phytogenic ; pharmacology ; Chalcones ; pharmacology ; Drugs, Chinese Herbal ; pharmacology ; Glycyrrhiza ; chemistry ; Humans