The use of and search for drugs and dietary supplements derived from plants have accelerated in recent years. Ethnopharmacologists, botanists, microbiologists, and natural-products chemists are combing the Earth for phytochemicals and “leads” which could be developed for treatment of infectious diseases. While 25 to 50% of current pharmaceuticals are derived from plants, none are used as antimicrobials. Traditional healers have long used plants to prevent or cure infectious conditions; Western medicine is trying to duplicate their successes. Plants are rich in a wide variety of secondary metabolites, such as tannins, terpenoids, alkaloids, and flavonoids, which have been found in vitro to have antimicrobial properties. This review attempts to summarize the current status of botanical screening efforts, as well as in vivo studies of their effectiveness and toxicity. The structure and antimicrobial properties of phytochemicals are also addressed. Since many of these compounds are currently available as unregulated botanical preparations and their use by the public is increasing rapidly, clinicians need to consider the consequences of patients self-medicating with these preparations.

Plant Products as Antimicrobial Agents

Thermo- and pH-responsive polymers in drug delivery.

Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S. Nagar,Mohali, Punjab-160 062, India, Institute of Biochemistry, Faculty of Medicine, Polytechnic University, Via Ranieri 67, IT-60100 Ancona, Italy,Green Biotechnology Research Group, The Special Division for Human Life Technology, National Institute of Advanced Industrial Science andTechnology, 1-8-31 Midorigaoka, Ikeda, Osaka-563-8577, Japan, and Department of Medicinal Chemistry & Natural Products,The Hebrew University of Jerusalem, School of Pharmacy-Faculty of Medicine, Jerusalem 91120, IsraelReceived March 2, 2004

Chitosan chemistry and pharmaceutical perspectives.

https://cmapspublic3.ihmc.us/rid=1266358861321_2027852911_13457/Wound%20Healing%20Dressings%20and%20Drug%20Delivery%20Systems.pdf

Wound healing dressings and drug delivery systems: a review.

The development of nonviral vectors for safe and efficient gene delivery has been gaining considerable attention recently. An ideal nonviral vector must protect the gene against degradation by nuclease in the extracellular matrix, internalize the plasma membrane, escape from the endosomal compartment, unpackage the gene at some point and have no detrimental effects. In comparison to viruses, nonviral vectors are relatively easy to synthesize, less immunogenic, low in cost, and have no limitation in the size of a gene that can be delivered. Significant progress has been made in the basic science and applications of various nonviral gene delivery vectors; however, the majority of nonviral approaches are still inefficient and often toxic. To this end, two nonviral gene delivery systems using either biodegradable poly(D,Llactide-co-glycolide) (PLG) nanoparticles or cell penetrating peptide (CPP) complexes have been designed and studied using A549 human lung epithelial cells. PLG nanoparticles were optimized for gene delivery by varying particle surface chemistry using different coating materials that adsorb to the particle surface during formation. A variety of cationic coating materials were studied and compared to more conventional surfactants used for PLG nanoparticle fabrication. Nanoparticles (~200 nm) efficiently encapsulated plasmids encoding for luciferase (80-90%) and slowly released the same for two weeks. After a delay, moderate levels of gene expression appeared at day 5 for certain positively charged PLG particles and gene expression was maintained for at least two weeks. In contrast, gene expression mediated by polyethyleneimine (PEI) ended at day 5. PLG particles were also significantly less

Nonviral Vectors for Gene Delivery

Two novel hepta-oxygenated flavonols have been isolated from the aerial parts of Premna oligotricha and identified, primarily on the basis of N M R spectroscopy, as 3,5,5'-trihydroxy- 6,7,3',4'-tetram ethoxyflavone (2) and 3,5,7,5'-tetrahydroxy-6,3',4'-trim ethoxyflavone (3). Known flavonoids, with lower levels of oxygenation were obtained from two other Premna species, P. schimperi and P. recinosa.

Flavonoids from Three Ethiopian Species of Premna

A xanthine alkaloid from the leaves of Bosistoa floydii

Phenylalkanoids from Piper marginatum.

A benzofuranone, 3,3a,7,7a-tetrahydro-3a-hydroxy-6(2H)-benzofuranone (1), was isolated from the flower of Nyctanthes arbortristis Linn. The compound was identified by 1D and 2D NMR and MS analyses. It showed significant antibacterial activity against both Gram positive and Gram negative bacteria. The LC50 of the compound was found to be 8.73 mg/ml in brine shrimp lethality bioassay. Key words: Nyctanthes arbortristis, Nyctantheceae; 3,3a,7,7a-tetrahydro-3a-hydroxy-6(2H)-benzofuranone, Antibacterial, Cytotoxicity 

Dhaka Univ. J. Pharm. Sci. Vol.4(1) 2005

The full text is of this article is available at the Dhaka Univ. J. Pharm. Sci. website

A Benzofuranone from the Flowers of Nyctanthes arbortristis and its Antibacterial and Cytotoxic Activities

In a recent study of the resin of Aucoumea klaineana several triterpenes with a tirucall-7-ene skeleton were isolated. X-ray diffraction analysis of flindissol lactone and flindissone lactone have confirmed the stereochemistry of the lactone ring formed through C21 and C23 to be (20S,23R), derived from a tirucallane precursor. A third triterpene was characterized as (225)-hydroxytirucalla-7,24-diene-3,23-dione.

Alexander I. Gray

Papers

Flavonoids from Three Ethiopian Species of Premna

A xanthine alkaloid from the leaves of Bosistoa floydii

Phenylalkanoids from Piper marginatum.

A Benzofuranone from the Flowers of Nyctanthes arbortristis and its Antibacterial and Cytotoxic Activities

Chemistry of the Burseraceae. XI. X-Ray-Diffraction Studies on Some Tirucall-7-ene Triterpenes From Aucoumea klaineana (Burseraceae)