Study On The Anti-diabetes Active Constituents Of Psidium Guajava Leaves

Psidium guajava linn, is blong to the Myrtaces family and Psidium genera, there was along history about guava leaf used to reduce blood sugar in and abroad. In recent years, therewere so many studies about guava leaf in the treatment of diabetes, but most of theresearchers were limited to compare the anti-diabetic activities of crude extract, and for itsspecific active constituents or structure-activity relationship no further explored.This paper summarizes the related theories and mechanisms of anti-diabetes and itscomplications and the research results of active ingredients, and takes it as a starting point,key separate the potential monomer composition of anti-diabetes. This experiment take3000gdry guava leaves, first with70%ethanol extraction get crude extract, quiet place stratification,take precipitation site into paste (422g), then use different polarity solvent for extraction andseparation, in turn by petroleum ether, ethyl acetate, l-butanol, methanol,70%ethanol,respectively, have to each place for dry paste30g,97g,235g,30g and25g. From thePetroleum ether parts, six compounds in eight compounds isolated were analysised,which aremeroterpenoids with unusual skeletons from the Leaves of Psidium guajava: PsiguadialA(PG-1,45mg), Psiguadial B (PG-2,75mg), Guajadial(PG-3,130mg), X(PG-5，30mg)，Guavadial(PG-7，45mg) and Diaguavadials(PG-6(8)，22mg)，these last two compands werefirst isolated and their structures were determined by spectroscopic technology.This experiment study on the antioxidant activity of guava leaf extract parts, the resultsshow that the free radical scavenging DPPH experiment result is superior to the removal ofthe effect of hydroxyl radicals. The n-butyl alcohol parts has the the most powerful effect ofremoval of DPPH free radicals(at0.1mg/ml, the clearance rate is more than90%),thefollowing is the guava leave70%ethanol extract and acetic ester parts; relatively the ethylacetate parts has the best effect of removal hydroxyl radicals, the clearance rate is above90%at low concentration (0.05mg/ml), which is more than the guava leaf70%ethanol extract,n-butyl alcohol parts, petroleum ether parts and methanol parts.