915-32-2Relevant articles and documents
Studies on the constituents of medicinal and related plants in Sri Lanka. I. New triterpenes from Hedyotis lawsoniae
Kikuchi,Matsuda,Kadota,et al.
, p. 3906 - 3911 (1984)
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Pentacylic triterpenes from Lavandula coronopifolia: structure related inhibitory activity on α-glucosidase
Elsbaey, Marwa,Mwakalukwa, Rogers,Shimizu, Kuniyoshi,Miyamoto, Tomofumi
, p. 1436 - 1444 (2019/08/26)
Ten pentacyclic triterpenes (1-10) were isolated from Lavandula coronopifolia. We evaluated their α-glucosidase inhibitory activity, and found that the aglycones, 1, 2, 3, 4, 7 and 10 showed superior IC50 values to the positive control. In order to explain the structural requirements for α-glucosidase inhibitory activity, eleven derivatives were prepared, including one new compound, 2-formyl-(A)1–19α-hydroxy-1-norursane-2, 12-dien-28-oic acid 10c. The results demonstrated that a free hydroxyl at ring-A and a free carboxylic group at position 28 are key structural features for the α-glucosidase inhibitory activity, also that an ursane skeleton is optimum for the activity. Additionally, enzyme kinetic analysis of pomolic acid 2, the most potent compound, revealed that it inhibited α-glucosidase in a mixed-type manner. The molecular docking simulation validated this type of inhibition and highlighted the role of the C-3 hydroxyl and C-28 carboxylic groups in interaction with the enzyme in silico.
Ursolic Acid Isolated from the Leaves of Loquat (Eriobotrya japonica) Inhibited Osteoclast Differentiation through Targeting Exportin 5
Tan, Hui,Zhao, Chong,Zhu, Qinchang,Katakura, Yoshinori,Tanaka, Hiroyuki,Ohnuki, Koichiro,Shimizu, Kuniyoshi
, (2019/03/29)
One of the conventional strategies for treating osteoporosis is to eliminate the multinucleated osteoclasts that are responsible for bone resorption. Our previous study revealed that ursolic acid, isolated from leaves of loquat that is used as tasty tea in Japan, suppressed osteoclastogenesis. We confirmed that ursolic acid exhibited osteoclast differentiation inhibitory activity with an 50% inhibitory concentration (IC50) value of 5.4 ± 0.96 μM. To disclose its mechanism of action, this study first uses polymer-coated magnetic nanobeads to identify potential target proteins. As a result, we identified a nuclear exporter protein named exportin 5 (XPO5). Further studies demonstrated that knockdown of XPO5 significantly blocks osteoclast differentiation (P 0.01). Expression profiling of mature microRNAs in the cells revealed that downregulation of XPO5 by small interfering RNA or by ursolic acid could downregulate the expression of mature microRNA let-7g-5p during osteoclast differentiation (P 0.01). Collectively, our findings suggest that ursolic acid inhibits osteoclast differentiation through targeting XPO5, which provides further evidence for the healthy function of the tea. This study also provides new insights into the role of XPO5 and its mediated microRNAs in treatment for bone resorption diseases.