| Objective: In this article, the identification standards of Fagopyrum dibotrys(D.Don)Hara, including original, morphological and microscopic identification and TLC, were performed as its basis; a new method was established to compare the contents of total phenols, tannin, catechin, epicatechin and dimeric procyanidin B-2 of medicinal part from different harvesting time and different planting areas, also could combine with color values determination to analyze the correlations between color and quality.Methods: To study the major identification characteristics of fagopyri dibotryis rhizome through checking up on references, studied specimens, microscopic identification and TLC. Meanwhile, ultraviolet spectrometry and RP-HPLC were established in order to study the variation of total phenols, tannin, catechin,epicatechin and dimeric procyanidin B-2 of fagopyri dibotryis rhizome, which were from different habitats and harvesting time. Also, correlation analysis of each component content and color values were performed.Results: The study of microscopic identification showed that the cortex of the fibrous root is relatively narrow, with much reddish brown lumps and big vessel in it,also there are lots of reddish brown lumps in the cortex and the xylem of the rhizome.The transection of leafstalk looks like a semicircle, it contains 9~11 vascular bundle which in the shape of a semicircle, and a bigger vascular bundle in middle. The transection of the leaf showed it is a typical bifacial leaf, and two vascular bundles are arranged in opposing pairs, two types of stomata are distributed at the leaf epidermis. Additionally, massive simple and compound starch grains, reticulated vessel, pitted vessel, less scalariform vessel and calcium oxalate crystals were observed in the powder of the rhizomes. Similarly, calcium oxalate crystals,the non-glandular hair, spiral vessels were observed in the powder of mature flowers.Thepollen grains which fully covered by spike, is triangular or round in shape, has three apertures.The results showed that the range of total phenol content of 9 batches of herbs,3.630% ~ 5.660%, the range of tannin content, 2.153% ~ 4.057%; the range of total phenol content of 3 batches of traditional herb pieces, 2.364% ~ 3.819%,the range of tannin content, 2.340%~3.774%. The total phenols and tannin content of fagopyri dibotryis rhizome which from the same district Yichang were as follows:The content of total phenol,December>October>August>May; the content of tannin,May>August>October>December. Similarly, the total phenols content and tannin of fagopyri dibotryis rhizome which from different habitats were as follows:The content of total phenol, Taizhou> Yichang> Yongzhou> Yongchuan,the content of tannin, Yongchuan> Taizhou> Yongzhou> Yichang.The results showed that the range of catechin content of 9 batches of herbs,0.0055% ~ 0.0157%, the range ofepicatechin content, 0.0165% ~ 0.0672%,the range of dimeric procyanidin B-2 content, 0.1119% ~ 0.2761%; the range of catechin content of 3 batches of traditional herb pieces, 0.0032% ~ 0.0076%,the range of epicatechin content, 0.0102% ~ 0.0234%, the range of dimeric procyanidin B-2 content, 0.0325%~0.0947%. The catechin, epicatechin and dimeric procyanidin B-2 content of fagopyri dibotryis rhizome which from the same district Yichang were as follows: The content of catechin, May>August>October>December;the content of epicatechin, May>August>December>October, the content of dimeric procyanidin B-2, August>October>May>December; Similarly, the catechin,epicatechin and dimeric procyanidin B-2 content of fagopyri dibotryis rhizome which from different habitats were as follows: The content of catechin,Yongchuan >Taizhou >Yongzhou >Yichang; the content of epicatechin,Yongzhou >Yongchuan >Taizhou >Yichang; the content of dimeric procyanidin B-2,Yongzhou>Taizhou>Yongchuan>Yichang.The analysis about color and chemical composition shows that there was no significant correlation of L*?a*?b* with the contents of total phenols,tannin, epicatechin. However, L* was significantly and positively correlated with thecontents of catechin and dimeric procyanidin B-2, a* has significant negative relationship with the contents of catechin and dimeric procyanidin B-2, no significant correlation was observed between b* and these two components.Conclusion:The microscopic characteristics of rhizome,stem, leaf,flower of Fagopyrum dibotrys(D.Don)Hara were distinguished. The ultraviolet spectrometry and RP-HPLC were established to determine the content of the total phenol, tannin, catechin, epicatechin and dimeric procyanidin B-2 of 12 batches of samples. The result showed that the content of herbs is higher than that of the traditional herb pieces which chemical compositions may degrade in long storage time. Furthermore, except harvesting time, differenthabitats have great effect on the content determination of fagopyri dibotryis rhizome. The correlation analysis between the color and the chemical composition indicated that L* was correlated with the contents,in a certain range, L* is bigger, the content is higher. These analysis methods could be convenient to provide ideas in quality criteria and identification. |
PDF Full Text Request