3
fpowderglycoside（无定形粉末）含糖基多的苷2Color黄酮类化合物大多为黄色，其颜色主要与分子中是否存在交叉共轭体系，助色团的种类，数目及取代位置有关。■flavo
eFlavo
ola
dtheirglycosidesshowgrayishyellow（灰黄）toyellowchalco
e（查耳酮）showyellowtoora
geforthecrossco
jugativesystem（交叉共轭体系）■Flava
o
e二氢黄酮flava
a
ol二氢黄酮醇a
disoflavo
e异黄酮arecolorlessbecausetheabse
ceofcrossco
jugativesystem■Theflavo
e（黄酮）flavo
al（黄酮醇）with7OH7OCH3or4’OH4’OCH3pπco
jugativeexte
dco
jugativesystem（共轭系统延长）deepe
thecolor■A
thocya
idi
（花色素）showdiffere
tcoloratdiffere
tPHvaluePH7redPH85紫色PH85blueⅡOpticalrotatio
旋光性■flava
o
eflava
o
olflava
ol（黄烷醇）isoflava
o
ea
dtheirderivativeshaveopticalrotatio
fortheasymmetriccarbo
atom（不对称碳原子）Otheraglyco
esofflavo
oidshave
’topticalrotatio
■Theglycosidesofflavo
oid（黄酮苷类）haveopticalrotatio
forthesaccharidelevorotatory（左旋）ⅢSolubility溶解性（1）游离黄酮类化合物①Flavo
eflavo
ola
dchalco
earepla
emoleculara
dhavebigi
termoleculartractiveforcesotheydifficultydissolvei
waterA环和B环与羰基形成一个大π键，而具有平面性。②Flava
o
eflava
o
olare
’tpla
emoleculars（非平面分子）thesolubilityi
wateri
creaseIsoflavo
eis
’tpla
emolecularforthesterichi
dra
ce（立体阻碍）ofcarbo
yl（羰基）toBcircleA
thocya
i
ca
dissolvewaterbecauseitisio
iccompou
ds（花色素能溶于水因其为离子型化合物）③The
umberofOHi
creasethehydrophilicity水溶性i
creasewhilethelipophilcity脂溶性decreaseThei
flue
ceofOCH3isreverse（羟基被甲基化后脂溶性增加）Flavo
oids，commo
lyca
’tdissolvei
peforitsmultihydroxy多羟基）Thelipophilicityi
creaseforthe（methoxypre
yl（异戊烯基）2黄酮苷类Theglycosidesofflavo
oidseasililydissolvei
hotwaterMeOHEtOHca
’tdissolveordifficultydissolvei
be
ze
eEt2OCHCl3pe一般多糖苷比单糖苷水溶性大，3羟基苷比相应的7羟基苷水溶性大H2O黄酮苷游离黄酮MeOHEtOHCHCl3Et2OOHH2O
Ⅳ酸碱性1Acidity74’OHpπco
jugative5OHhydroge
bo
di
tromolecular74’OH5NaHCO37or4’OH5Na2CO3commo
ArOH02NaOH5OH4NaOH
4
fⅤColorreactio
1Colorreactio
byreductio
（还原反应）11HClMgpowderreactio
SampleEtOHalittleMgpowdershockaddseveraldropsco
cHCl（浓盐酸）flavo
eflavo
olflava
o
eflava
o
olshowredtovioletred紫红fewshowblueorgree
chalco
eauro
ecatechi
（儿r