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Alexander I. Gray

Bio: Alexander I. Gray is an academic researcher from Strathclyde Institute of Pharmacy and Biomedical Sciences. The author has contributed to research in topics: Eriostemon & Trypanosoma brucei. The author has an hindex of 41, co-authored 292 publications receiving 6648 citations. Previous affiliations of Alexander I. Gray include University of Strathclyde & Netaji Subhas Institute of Technology.


Papers
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BookDOI
01 Jan 2005
TL;DR: Natural Product Isolation: An Overview Satyajit D. Sarker and Lutfun Nahar Purification by Solvent Extraction Using Partition Coefficient Hideaki Otsuka Crystallization in Final Stages of Purification.
Abstract: Natural Product Isolation: An Overview Satyajit D. Sarker, Zahid Latif, and Alexander I. Gray Initial and Bulk Extraction Veronique Seidel Supercritical Fluid Extraction Lutfun Nahar and Satyajit D. Sarker An Introduction to Planar Chromatography Simon Gibbons Isolation of Natural Products by Low-Pressure Column Chromatography Raymond G. Reid and Satyajit D. Sarker Isolation by Ion-Exchange Methods David G. Durham Separation by High-Speed Countercurrent Chromatography James B. McAlpine and Patrick Morris Isolation by Preparative High-Performance Liquid Chromatography Zahid Latif Hyphenated Techniques Satyajit D. Sarker and Lutfun Nahar Purification by Solvent Extraction Using Partition Coefficient Hideaki Otsuka Crystallization in Final Stages of Purification Alastair J. Florence, Norman Shankland, and Andrea Johnston Dereplication and Partial Identification of Compounds Laurence Dinan Extraction of Plant Secondary Metabolites William P. Jones and A. Douglas Kinghorn Isolation of Marine Natural Products Wael E. Houssen and Marcel Jaspars Isolation of Microbial Natural Products Russell A. Barrow Purification of Water-Soluble Natural Products Yuzuru Shimizu and Bo Li Scale-Up of Natural Product Isolation Steven M. Martin, David A. Kau, and Stephen K. Wrigley Follow-Up of Natural Product Isolation Richard J. P. Cannell Index

313 citations

Journal ArticleDOI
01 Aug 2007-Methods
TL;DR: Standard methods recommended by the Clinical and Laboratory Standards Institute are compared with a microtitre assay using a metabolic colour indicator Alamar blue, which enables high throughput screening, under similar conditions and is less wasteful of plant material.

164 citations

Journal ArticleDOI
TL;DR: Four pentacyclic tritepenes were isolated from Combretum imberbe Engl.

157 citations

Journal ArticleDOI
TL;DR: A benzoisofuranone derivative and a dimeric carbazole alkaloid, 3,3'-[oxybis(methylene)]bis(9-methoxy-9H-carbazole), along with six known carbazoles alkaloids and three known steroids were isolated from the stem bark of Murraya koenigii.

157 citations

Journal ArticleDOI
TL;DR: It is concluded that the polypropylenimine dendrimers are promising gene delivery systems which may be used to target the liver and avoid the lung and also that molecular modifications conferring colloidal stability on gene delivery formulations have a profound effect on their tolerability on intravenous administration.

136 citations


Cited by
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Journal ArticleDOI
TL;DR: The current status of botanical screening efforts, as well as in vivo studies of their effectiveness and toxicity, are summarized and the structure and antimicrobial properties of phytochemicals are addressed.
Abstract: 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.

7,486 citations

Journal ArticleDOI
TL;DR: The majority of examples, discussed in this paper, deal with pH-responsive drug delivery system, and Thermo-responsive polymer is also covered to a large extent, as well as double-responsive system.

2,746 citations

Journal ArticleDOI
TL;DR: Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. S. Nagar, Punjab-160 062, India, Institute of Biochemistry, Faculty of Medicine, Polytechnic University, Via Ranieri 67, IT-60100 Ancona, Italy, and Department of Medicinal Chemistry & Natural Products,The Hebrew University of Jerusalem, School of Pharmacy-Faculty of medicine, Jerusalem 91120, Israel.
Abstract: 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

2,570 citations

Journal ArticleDOI
TL;DR: The requirement for formulations with improved properties for effective and accurate delivery of the required therapeutic agents and general formulation approaches towards achieving optimum physical properties and controlled delivery characteristics for an active wound healing dosage form are considered.

2,302 citations

Journal ArticleDOI
TL;DR: 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.
Abstract: 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

2,189 citations