Saponins from Quillaja saponaria Molina: Isolation, Characterization and Ability to Form Immuno Stimulatory Complexes (ISCOMs)

Pham, H. L., Ross, B. P., McGeary, R. P., Shaw, P. N., Hewavitharana, A. K. and Davies, N. M. (2006) Saponins from Quillaja saponaria Molina: Isolation, Characterization and Ability to Form Immuno Stimulatory Complexes (ISCOMs). Current Drug Delivery, 3 4: 389-397. doi:10.2174/156720106778559092


Author Pham, H. L.
Ross, B. P.
McGeary, R. P.
Shaw, P. N.
Hewavitharana, A. K.
Davies, N. M.
Title Saponins from Quillaja saponaria Molina: Isolation, Characterization and Ability to Form Immuno Stimulatory Complexes (ISCOMs)
Formatted title
Saponins from Quillaja saponaria Molina: Isolation, Characterization and Ability to Form Immuno Stimulatory Complexes (ISCOMs)
Journal name Current Drug Delivery   Check publisher's open access policy
ISSN 1567-2018
Publication date 2006-10
Sub-type Article (original research)
DOI 10.2174/156720106778559092
Volume 3
Issue 4
Start page 389
End page 397
Total pages 9
Place of publication Netherlands
Publisher Bentham Science
Collection year 2006
Language eng
Subject C1
320501 Pharmaceutical Sciences and Pharmacy
730101 Infectious diseases
Abstract ISCOMs have received much attention as vaccine adjuvants due to their immunostimulatory effects. They are colloidal particles typically comprised of phospholipids, cholesterol and Quil A, a crude mixture of saponins extracted from the bark of Quillaja saponaria Molina. We have previously shown that ISCOMs can be prepared by ether injection wherein an ether solution of phospholipids and cholesterol in a mass ratio of 5:2 is injected into a solution of Quil A at a mass ratio of 7 lipids: 3 Quil A. The aim of this study was firstly to isolate and characterise discrete fractions of Quil A and secondly to investigate which of these fractions were able to form ISCOMs by the method of ether injection. Six fractions of Quil A were isolated by semi-preparative reverse phase high performance liquid chromatography (RP-HPLC) and characterised by analytical HPLC, liquid chromatography tandem mass spectrometry (LC-MS) and the qualitative Liebermann- Burchard and Molisch tests for triterpenoids and carbohydrates respectively. ISCOMs were subsequently prepared from the isolated fractions by the method of ether injection and the resulting preparations characterized by photon correlation spectroscopy (PCS) and negative stain transmission electron microscopy (TEM). The molecular weights of the major compounds in the fractions ranged from ∼1200 to ∼2300 Da; all fractions tested positive for triterpenoids and saccharides and four of the fractions were identified as QS-7, QS-17, QS-18 and QS-21 by analysis (LC-MS and analytical HPLC). Injection of ether solutions of lipids into aqueous solutions of QS-17, QS-18 or QS-21 all resulted in homogeneous ISCOM dispersions. The combination of lipids and QS-7 by ether injection produced lamellae and liposomes as the prominent structures and a minor amount of ISCOMs. The remaining two hydrophilic, low molecular weight fractions of Quil A did not produce ISCOMs, instead liposomes and helical structures predominated in the samples.
Keyword ISCOM
Immuno-stimulating complex
Quil A
ether injection
drug delivery
vaccine delivery
Q-Index Code C1

Document type: Journal Article
Sub-type: Article (original research)
Collections: Excellence in Research Australia (ERA) - Collection
2007 Higher Education Research Data Collection
School of Pharmacy Publications
 
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Created: Wed, 15 Aug 2007, 10:02:25 EST