[Determination of apparent oil-water partition coefficient of andrographolide and dehydroandrographolide and effect of pH on them].
OBJECTIVE
To determine the apparent n-octanol-water/buffer partition coefficient of andrographolide and dehydroandrographolide.


METHODS
The apparent n-octanol-water/buffer partition coefficients of andrographolide and dehydroandrographolide were measured by shaking flask method. The concentrations of andrographolide and dehydroandrographolide were analyzed by HPLC method.


RESULTS
The Papp of andrographolide and dehydroandrographolide were 3.90 (log Papp = 0.59) and 19.75 (log Papp = 1. 30) in water at 37 degrees C, respectively.


CONCLUSIONS
The apparent n-octanol-buffer partition coefficients of andrographolide and dehydroandrographolide are influenced by pH, and the higher pH may decrease the apparent n-octanol-buffer partition coefficients of them. Andrographolide has the highest partition coefficient in pH6, and dehydroandrogapholide in pH5.
Yao
Yuan
Y
College of Chinese Traditional Medicine, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
Liao
Qiong-Feng
QF
Zeng
Li-Ying
LY
Zhang
Lei
L
Ma
Yan
Y
Zeng
Yuan-Er
YE
D035685:Andrographis / Q000737:chemistry*; D002021:Buffers; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D006863:Hydrogen-Ion Concentration; D007783:Lactones / Q000737:chemistry*; D015394:Molecular Structure; D000442:Octanols; D009821:Oils / Q000737:chemistry*; D010946:Plants, Medicinal / Q000737:chemistry*; D012995:Solubility; D013696:Temperature; D014867:Water / Q000737:chemistry*
D002021:Buffers; D007783:Lactones; D000442:Octanols; D009821:Oils; D014867:Water