红紫珠二萜类成分及其抗炎活性研究

Diterpenoids of Callicarpa rubella and their anti-inflammatory activity

目的研究红紫珠Callicarpa rubella枝叶的二萜类化学成分及其体外抗炎活性。方法采用多种色谱方法对红紫珠化学成分进行系统分离纯化,运用核磁共振谱、质谱及X-单晶衍射实验等技术鉴定化合物结构。以脂多糖(lipopolysaccharide,LPS)诱导的小鼠巨噬细胞RAW264.7为抗炎模型,选择6个结构差异明显的二萜类化合物进行抗炎活性评价。结果从红紫珠石油醚部位和醋酸乙酯部位共分离得到20个二萜类化合物,分别鉴定为kolavic acid-15-metyl ester(1)、rubellapene A(2)、rubellapene B(3)、rubellapene C(4)、13,14,15,16-四降碳-3-克罗-12,18-二羧酸(5)、对映异海松烷-8(14),15-烯-19-羧酸(6)、dichrocephnoids C(7)、15-去甲基半日-8(20)12E-二烯-14-甲醛-19-羧酸(8)、8S-kolavic acid 15-methyl ester(9)、粘叶莸酸(10)、melanocane B(11)、dodovislactones B(12)、tinotufolin B(13)、amphiacric acid A(14)、patagonic acid(15)、(+)-15-methoxyfloridolide A(16)、去甲基-左旋哈氏豆属酸(17)、15-羟基-16-羰基-15,16H-左旋哈氏豆属酸(18)、(−)-顺式-克罗-3,13-烯-16-羟基-15,18-二羧酸-15,16-内酯(19)、polylauioid J(20)。结论首次得到化合物1的单晶X射线衍射晶体结构数据。化合物5、7~14、16~20为首次从紫珠属植物中分离,其余化合物为首次从红紫珠中分离得到,主要以克罗烷型和半日花烷型二环二萜为主。体外抗炎活性实验表明,6个二萜类化合物均能够抑制LPS刺激的小鼠RAW264.7巨噬细胞中NO的分泌,其中化合物1抑制NO能力最强,推测C-13位双键的存在有利于提高抗炎活性。

Objective To study the diterpenoids of branches and leaves of Callicarpa rubella and their anti-inflammatory activity in vitro.Methods The diterpenoids of C.rubella were systematically isolated and purified by various chromatographic methods.The structures of diterpenoids were identified by nuclear magnetic resonance(NMR),mass spectrometry(MS)and X-single crystal diffraction methods.A total of six diterpenoids with distinct structural differences were selected to evaluate the anti-inflammatory activity by means of exploring lipopolysaccharide(LPS)-induced mouse macrophage RAW264.7 cells.Results A total of tweenty diterpenoids were isolated from the petroleum ether and ethyl acetate parts of C.rubella,and their structures were identified as follows:kolavic acid-15-metyl ester(1),rubellapene A(2),rubellapene B(3),rubellapene C(4),13,14,15,16-tertranor-3-clerodene-12,18-dioic acid(5),ent-isopimar-8(14),15-dien-19-oic acid(6),dichrocephnoids C(7),15-norlabda-8(20)12E-diene-14-carboxaldehyde-19-oic acid(8),8S-kolavic acid 15-methyl ester(9),glutinic acid(10),melanocane B(11),dodovislactones B(12),tinotufolin B(13),amphiacric acid A(14),patagonic acid(15),(+)-15-methoxyfloridolide A(16),nor-hardwicknc acid(17),15-hydroxy-16-oxo-15,16H-hardwickiic acid(18),(−)-cis-cleroda-3,13-dien-16-hydroxy-15,18-dioic acid-15,16-olide(19),polylauioid J(20).Conclusion The single crystal X-ray diffraction data of compound 1 was obtained for the first time.Compound 5,7—14,and 16—20 were isolated from the genus of Callicarpa for the first time,and the others were isolated for the first time from C.rubella.The structures were mainly clerodane and labdane type.In vitro anti-inflammatory activity experiments showed that six diterpenoids could inhibit NO secretion in mouse RAW264.7 macrophages stimulated by LPS,among which compound 1 exhibited the strongest inhibiting activity of NO secrection.It was speculated that the presence of double bond at C-13 position was beneficial for enhancing anti-inflammatory activity.