title: ent-Kaurane diterpenoids from Croton tonkinensis stimulate osteoblast differentiation.
abstract: Four new ent-kaurane diterpenoids (1-4) were isolated from the leaves of Croton tonkinensis by bioactivity-guided fractionation using an in vitro osteoblast differentiation assay. Their structures were identified as ent-11β-acetoxykaur-16-en-18-ol (1), ent-11α-hydroxy-18-acetoxykaur-16-ene (2), ent-14β-hydroxy-18-acetoxykaur-16-ene (3), and ent-7α-hydroxy-18-acetoxykaur-16-ene (4). Compounds 1-4 significantly increased alkaline phosphatase activity and osteoblastic gene promoter activity. Compounds 1-3 also increased the levels of ALP and collagen type I alpha mRNA in C2C12 cells in a dose-dependent manner. These results suggest that ent-kaurane diterpenoids from C. tonkinensis have a direct stimulatory effect on osteoblast differentiation and may be potential therapeutic molecules against bone diseases such as osteoporosis.
authors.affiliation: BK21 Project Team, College of Pharmacy, Chosun University, 375 Seosuk-dong, Dong-gu, Gwangju 501-759, Republic of Korea.
authors.forename: Trong-Tuan
authors.initials: TT
authors.lastname: Dao
authors.forename: Kwang-Youl
authors.initials: KY
authors.lastname: Lee
authors.forename: Hyung-Min
authors.initials: HM
authors.lastname: Jeong
authors.forename: Phi-Hung
authors.initials: PH
authors.lastname: Nguyen
authors.forename: Tien Lam
authors.initials: TL
authors.lastname: Tran
authors.forename: Phuong-Thien
authors.initials: PT
authors.lastname: Thuong
authors.forename: Bich-Thu
authors.initials: BT
authors.lastname: Nguyen
authors.forename: Won-Keun
authors.initials: WK
authors.lastname: Oh
mesh_terms: D000818:Animals; D029802:Croton / Q000737:chemistry*; D045786:Diterpenes, Kaurane / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D051379:Mice; D015394:Molecular Structure; D032446:Myoblasts / Q000187:drug effects; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry; D014744:Vietnam
chemical_list: D045786:Diterpenes, Kaurane