Puerarin-7-O-fructoside was transformed by Trichoderma harzianum CGMCC 1523 into 3'-hydroxypuerarin-7-O-fructoside; this was identified by MS and NMR. However, puerarin-7-O-glucoside was not directly hydroxylated but hydrolyzed back into puerarin, which was transformed into 3'-hydroxypuerarin by the same fungi. Comparative analysis of free radical scavenging activity of DPPH showed that the free radical scavenging activity of puerarin-7-O-glucoside was reduced to approximately 1/2 of that of puerarin, while the free radical scavenging activity of puerarin-7-O-fructoside was increased to approximately 1.5 times of that of puerarin. The free radical scavenging activity of 3'-hydroxypuerarin-7-O-fructoside was further increased by 2.2 times of that of puerarin-7-O-fructoside, which was close to that of 3'-hydroxypuerarin.

flavonoid, naringin, DPPH, free radical scavenge activity, puerarin

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6	C7	C8	C9	C10	C11	C12	C13	C14	C15
7	bDFruf	62.0	104.6	82.6	77.2	75.7	62.8
8	bD1dGlcp	73.9	71.3	78.9	70.9	80.2	61.7
	Subst	125.9	123.7	175.3	126.6	115.8	161.4	112.9	152.9	117.3	123.5	115.8	145.2	145.7	117.1	120.2


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6	H7	H8	H9	H10	H11	H12	H13	H14
7	bDFruf	3.41	-	3.52	3.95	3.79	3.88
8	bD1dGlcp	4.80	3.93	3.16-3.39	?	?	?
	Subst	8.25	-	-	7.92	6.97	-	-	-	-	-	7.03	-	-6.75	6.81


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6	C7/H7	C8/H8	C9/H9	C10/H10	C11/H11	C12/H12	C13/H13	C14/H14
7	bDFruf	62.0/3.41		82.6/3.52	77.2/3.95	75.7/3.79	62.8/3.88
8	bD1dGlcp	73.9/4.80	71.3/3.93	78.9/3.16-3.39	70.9/?	80.2/?	61.7/?
	Subst	NMR TSV error 2: unequal length of 13C and 1H datasets

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

O=c1c(-c2ccc(O)cc2)coc2c([C@@H]3O[C@H](CO)[C@@H](O)[C@H](O)[C@H]3O)c(O[C@]3(CO)O[C@H](CO)[C@@H](O)[C@@H]3O)ccc12

578.523 g/mol (C₂₇H₃₀O₁₄)

Evaluation of the constitutive polyphenolics of the whole plant extract of Epilobium hirsutum was carried out by reverse-phase HPLC. The unique ellagitannins, 2-O-galloyl 3-O-valoneoyl dilactone-(α/β)-C-4(1)-glucopyranose, 1'-monodecarboxyvaloneic acid dilactone and valoneic dilactone dioxine were isolated and characterized. The known polyphenolics, gallic, protocatechuic, ellagic, valoneic dilactone and p-coumaric acids, methyl gallate, p-methoxy gallic acid methyl ester, 6-O-galloylglucose, 1,6-di-O-galloylglucose, 2,3-di-O-galloylglucose, 1,2,6-tri-O-galloylglucose and the 3-O-glucuronides, 3-O-arabinosides and 3-O-rhamnosides of kaempferol, quercetin and myricetin, their free aglycones 3-O-galactoside and quercetin and myricetin were also identified. The structures were established by conventional methods of analysis and confirmed by H-1, C-13 NMR and negative ESI-mass spectrometry. 2D-long range selective proton decoupling and chemical shift correlation NMR experiments were applied for the new polyphenolics. The HPLC phenolic profile was used for the quality.

NMR, flavonoids, Onagraceae, Epilobium hirsutum, ellagitannins, gallotannins, 2-O-galloyl 3-O-valoneoyl dilactone-(a/b)-4C1-glucopyranose, 1’-monodecarboxyvaloneic acid dilactone, valoneic dilactone dioxine, HPLC quality assessment of the extract

13C NMR data:
Linkage	Residue	C1	C2	C3	C4	C5	C6
7',2	xXGallic
7'	aDGlcp	90.6	73.1	74.1	69.7	72.5	62.1
	Subst


1H NMR data:
Linkage	Residue	H1	H2	H3	H4	H5	H6
7',2	xXGallic
7'	aDGlcp	5.20	4.88	5.68	3.79	3.91	3.69-3.73
	Subst


1H/13C HSQC data:
Linkage	Residue	C1/H1	C2/H2	C3/H3	C4/H4	C5/H5	C6/H6
7',2	xXGallic
7'	aDGlcp	90.6/5.20	73.1/4.88	74.1/5.68	69.7/3.79	72.5/3.91	62.1/3.69-3.73
	Subst

There is only one chemically distinct structure:

SVGMWSMILES3D molIonize

 

O=C(O[C@H]1[C@@H](O)O[C@H](CO)[C@@H](O)[C@@H]1OC(=O)c1cc(O)c(O)c(O)c1Oc1cc2c(=O)oc3c(O)c(O)cc4c(=O)oc(c1O)c2c34)c1cc(O)c(O)c(O)c1

784.544 g/mol (C₃₄H₂₄O₂₂)