Angelica gigas Nakai (AGN) is a traditional medicinal herb especially in Korea. It contains pyranocoumarins, which are major active components including decursin (D) and decursinol angelate (DA). This study was carried out to determine the change in active component content and antioxidant activity depending on the root diameter of AGN. Several processing steps are involved to use AGN roots as medicine. The dried AGN roots are divided into body (B), thick root (TkR), medium root (MR) and thin root (TnR) according to their diameter before cutting into medicine. The recovery rates of each root parts per 100 ㎏ were measured as 32.3±2.5, 9.0±1.0, 39.3±2.1 and 15.0±1.0%, respectively and the mean diameters were measured as 51.95±4.55, 7.05±0.89, 2.88±0.49 and 1.57±0.32 ㎜. Two index components, D and DA, were analyzed. The change of both D and DA content showed a similar tendency. Both D and DA content were increased as the root diameter decreased (higher in TnR). In addition, antioxidant activity was higher in B and TnR, and lower in TkR and MR than control. This study showed that the thinner the root diameter, the higher the D and DA content in AGN roots and that TnR has excellent antioxidant activity compared to other root parts, suggesting that the thinner root part of AGN could be used as a potential material.

The use of Rehmannia glutinosa of the family Scrophulariaceae, in traditional medicine is well known. This study was conducted to elucidate the effect of air curing of the seed rhizome of R. glutinosa on its storability and yield. Methods and Results: The root of the R. glutinosa cultivar (Dagang) was harvested in at the end of November. The seed rhizomes were air cured for one to seven days. They were subsequently wrapped with newspaper and further stored in a plastic container at 1℃. It was observed that the weight loss and decay rates were significantly lower in the air cured seeds than in the untreated ones. Moreover, the decay rate of the control was approximately 50%, 120 days after storage. However. the decay rate of all the air cured treatment groups was less than 1%. Additionally, air curing led to an increase in the germination rate of the seeds and the root yield when compared with the untreated groups. Taken together, the ideal treatment period for air curing was found to be 3 days. Under these conditions, the germination rate and yield were 88.7% and 2,185 ㎏/10a, respectively. Conclusions: This study successfully demonstrated that the air curing of seed rhizomes can lead to a considerable increase in the storability and yield of R. glutinosa.

Background: Angelica gigas Nakai is a perennial herb belonging to the family Umbelliferae. Its roots are utilized in traditional medicine. The aim of this study was to increase the yield of and the content of two indicator components (decursin and decursinol angelate) in A. gigas Nakai. Methods and Results: The roots of A. gigas Nakai were harvested 4-times from late August to late October in 2017. Two agents (trace element-TE, and plant hormone-HM) were applied 4 times at intervals of 2 weeks. The content of the two indicator components were analyzed by high performance liquid chromatography. The HM treatment showed the greatest increase in underground part yield and root diameter. The content of the two indicator components in the control (non-treatment) group was the highest in the underground part, but was higher in the aerial parts in the agent treatment group. After treatment with the agents, the content of the indicator components tended to decrease in the underground part. However, the total content of the indicator components in the two agent treatment groups exceeded the level of 6% set by the Korean Pharmacopoeia. Conclusions: The highest underground part yield was found in the HM treatment group, while the highest content of decursin and decursinol angelate were found in the control group. This study provides basic information for yield improvement in A. gigas.

Background : Rehmannia glutinosa belonging to the family of Scrophulariaceae have been utilized as a traditional medicine. This study was conducted to elucidate an effect of air curing for seed rhizome of R. glutinosa on storaging ability and yield. Methods and Results : The root of R. glutinosa cultivar (Dagang) was harvested in the end of November. Seed rhizomes were air curing for one to seven days then wrapped with newspaper and further stored in a plastic container box at 1℃. The weight loss and decay rates were significantly lower in seed air curing treatment than in untreated. Especially, the decay rate of control was approximately 50% at 120 days after storage. But, the decay rate of all air curing treatment groups was less than 1%. Also air curing led to an increase in germination rate of seeds and root yield compared with untreatment. Taken together, the best air curing treatment period was 3 days, under the that conditions, germination rate and yield were 88.7% and 2,185 ㎏/10 a, respectively. Conclusion : This study has successfully demonstrated that the air curing of rhizome as a seeds led to considerable increasement of both storaging ability and yield in R. glutinosa.

Background : Angelica gigas is a perennial herb belonging to the family Umbelliferae. Its roots have been utilized as a traditional medicine. The aim of this study is to increase the yield and two indicator components (decursin and decursinol angelate) of Angelica gigas. Methods and Results : The roots of A. gigas were harvested 4 times from early September to late October. Two elicitors (micro element, plant hormone) were treated 4 times at intervals of 2 weeks. The two indicator components were analyzed by HPLC. HM treatment group showed the greatest increase in underground part yield and root diameter. The content of two indicator components in underground part were highest in control (non-treatment) group, but the content of elicitor treatment groups were higher in the aerial part. In the ground part of indicator components content tended to decrease in the elicitor treatment groups, but that groups exceeded the total content of indicator components level of 6% set by the Korean Pharmacopoeia. Conclusion : The highest underground part yield was found in HM treatment group. The highest decursin and decursinol angelate were found in control group. This study provides the basic information for improvement to yield of A. gigas.