張 琪,韓明虎
(隴東學院 化學化工學院,甘肅 慶陽 745000)
五加屬植物又名刺五加,廣泛分布于亞洲各國,主要生長于喜馬拉雅山脈周圍及亞洲東部如中國、韓國、日本、朝鮮、俄羅斯東北部、蒙古、印度、不丹和尼泊爾等。作為《中華人民共和國藥典》中的中藥之一,五加屬植物的藥用、食用價值頗高,在醫(yī)藥、生物領域應用前景廣闊[1-2]。截至目前,研究人員已經從五加屬植物的根、莖、葉、果實和種子等不同部位分離鑒定出多種化學成分,主要包括萜類、木脂素、黃酮、茋、生物堿、甾醇、香豆素等。同時,還發(fā)現(xiàn)多種無機元素、氨基酸、單糖、多糖、揮發(fā)油等成分,相對比較復雜[3-5]。其中,萜類化合物含量高且種類繁多,具有抗氧化、抗風濕、抗應激、抗疲勞、抗腫瘤、抗病毒、抗?jié)?、抗輻照和強化骨骼等多種生物活性,臨床可用于治療糖尿病、冠心病、心絞痛、風濕痹痛、腰膝軟弱及神經衰弱等疾病,能有效緩解短暫性腦缺血發(fā)作、動脈硬化、血栓形成和腦栓塞等癥狀,其生物活性的多樣性和重要性備受人們的重視,已成為中藥化學研究的一個熱點領域[6-8]。
鑒于五加屬植物中萜類化合物已有潛在的藥用價值,結合國內外最新研究成果,對其化學成分、生物活性與臨床應用進行了系統(tǒng)整理和總結,為新藥、食品、保健品的市場開發(fā),植物化學和結構鑒定的進一步研究提出依據(jù)。
萜類是五加屬植物中種類最多且含量較高的化合物。目前,國內外學者從五加屬植物中已分離得到約180余種萜類及其皂苷,包括三萜(A)、二萜(B)及倍半萜(C)等。其中三萜類化合物大多為五環(huán)結構,分為羽扇豆烷型、3,4-seco-羽扇豆烷型與齊墩果烷型,自然界大多以游離狀態(tài)或成苷或成酯的形式存在,生物活性與藥理功能良好,是中藥化學研究的熱點領域之一[9]。系列化典型代表有Acantrifoside A、B、C,Acankoreoside A、B、C、D、E、F、G、H、I、J、K、L、M、N、O,Wujiapioside A、B,Acanjaposide A、B、D、E、F、G、H、I,Acanthopanaxoside A、B、C、E,Ciwujianoside A1、A2、A3、A4、B、C1、C2、C3、C4、D1、D2、D3、E,Nipponoside A、B、C、D、E,Eleutheroside L、M、K,Spinoside C1、C2、C3、C4、C5、C6、C7、D1、D2、D3,SpinogeninD2、D3等,部分化合物結構見圖1[10-45]。
AR1R2R3R4R51HCH3HHCH32HCH3HOHCH33HCOOHHHCH34HCHOHOHCH35HCH2OHHOHCH36HCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-RhaOHCH37HCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-RhaHCH38HCH2OH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-RhaOHCH39HCH2OH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-RhaHCH310HCHO←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-RhaOHCH311HCHO←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-RhaHCH312HCOOH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-RhaHCH2OH13HCOOH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-RhaOHCH2OH14HCHO←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-RhaHCH2OH15HCHO←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-RhaOHCH2OH16HCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-RhaHCH317←1)-β-D-GlcCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-RhaOHCH318←1)-β-D-GlcCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-RhaOHOH19CHOCOOHHHCH2OH20CHOCOOH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-RhaHCH2OH
AR1R2R322CHOCOOH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha23COOHCHO←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha24CH3OH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha25HH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha26CH3H←1)-β-D-Glc-(6←1)-β-D-Glc27CH3HH28CH3H←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha29CH3OH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha30CH3OHH31CH3OOCH3H32CH2OHHH33CH2OHH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha34HCH3H35←1)-α-L-AraCH3H36←1)-α-L-Ara-(2←1)-α-L-RhaCH3H37←1)-α-L-Ara-(2←1)-β-D-GlcCH3H38←1)-α-L-Ara-(3←1)-β-D-Glc-(3←1)-α-L-RhaCH3H39←1)-α-L-Ara-(2←1)-β-D-GlcCH3←1)-β-D-Glc-(6←1)-β-D-Glc-[(6←Ac)]-(4←1)-α-L-Rha40←1)-α-L-Ara-(2←1)-α-L-RhaCH3←1)-β-D-Glc-(6←1)-β-D-Glc-[(6←Ac)]-(4←1)-α-L-Rha41←1)-α-L-Ara-(2←1)-β-D-GlcCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha42←1)-α-L-Ara-(2←1)-α-L-RhaCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha43←1)-α-L-AraCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha44←1)-α-L-AraCH3←1)-β-D-Glc-(6←1)-β-D-Glc-[(6←Ac)]-(4←1)-α-L-Rha45HCHO←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha46HCOOH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha47HCH3H48←1)-α-L-AraCH3H49←1)-α-L-Ara-(4←1)-α-L-RhaCH3H50←1)-β-D-GlcA-[(6←OCH3)]-(2←1)-α-L-AraCH3H51←1)-α-L-Ara-(2←1)-β-D-GlcCH3←1)-β-D-Glc-(6←1)-β-D-Glc-[(6←Ac)]-(4←1)-α-L-Rha52←1)-α-L-Ara-(2←1)-β-D-GlcCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha53←1)-β-D-GlcCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha54←1)-α-L-Ara-(2←1)-α-L-RhaCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha55←1)-α-L-Ara-(2←1)-α-L-RhaCH3H56←1)-β-D-GlcACH3H57←1)-β-D-GlcA-(6←OCH3)CH3H58←1)-β-D-GlcA-(6←OCH2CH2CH2CH3)CH3H59←1)-β-D-Glc-(4←1)-α-L-Ara-(2←1)-β-D-GlcCH3←1)-β-D-Glc-(6←1)-β-D-Glc60←1)-β-D-GlcACH3←1)-β-D-Glc61←1)-β-D-GlcACH3←1)-β-D-Glc-(6←1)-β-D-Glc62←1)-α-L-Ara-(2←1)-α-L-RhaCH3←1)-β-D-Glc-(6←1)-β-D-Glc63←1)-α-L-Ara-(4←1)-α-L-RhaCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha64←1)-α-L-AraCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha65←1)-α-L-Ara-(2←1)-α-L-RhaCH3←1)-β-D-Glc-(6←1)-β-D-Glc-[(6←Ac)]-(4←1)-α-L-Rha66←1)-α-L-AraCH3←1)-β-D-Glc-(6←1)-β-D-Glc-[(6←Ac)]-(4←1)-α-L-Rha67←1)-α-L-Ara-(2←1)-β-D-GlcCH3←1)-β-D-Glc-(6←1)-β-D-Glc68←1)-α-L-Ara-(2←1)-α-L-Rha-(3←1)-β-D-XylCH3H69←1)-α-L-Ara-(2←1)-α-L-Rha-(3←1)-β-D-XylCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha70←1)-α-L-Ara-(2←1)-β-D-GlcCH3H71HCH2OHH72←1)-α-L-AraCH2OHH73←1)-α-L-Ara-(2←1)-α-L-RhaCH2OHH74←1)-α-L-Ara-(2←1)-α-L-GlcCH2OHH75←1)-α-L-Ara-(2←1)-α-L-RhaCH2OH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha76←1)-α-L-AraCH2OH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha77←1)-α-L-Ara-(2←1)-β-D-GlcCH2OH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha
AR1R2R378←1)-α-L-AraCH2OH←1)-β-D-Glc-(6←1)-β-D-Glc-[(6←Ac)]-(4←1)-α-L-Rha79←1)-α-L-Ara-(2←1)-β-D-GlcCH2OH←1)-β-D-Glc-(6←1)-β-D-Glc-[(6←Ac)]-(4←1)-α-L-Rha80CH3COOH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha81CHOCOOH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha82CH2OHCOOH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha83CH3CH2OH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha84CHOCH2OH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha85CH2OHCH2OH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha86CH3OH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha87CHOOH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha88CH2OHOH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha89CH3COOHH90CH2OHCH3←1)-β-D-Glc91CH2OHCOOHH92CHOCOOHH93CH2OHCH3CH3
AR1R2R3R494CH3OHH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha95HOHOHH96HOHHH97HOHH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha98HHHH99HHH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha100HCH3COOHH101←1)-α-L-Ara-(2←1)-α-L-RhaCH3COOHH102HCH2OHCH3←1)-β-D-Glc103HCH2OHCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha104HCH2OHOH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha105HCH2OHCH3H106HCH2OHCH3CH3107←1)-β-D-GlcACH2OHCH3H108←1)-α-L-AraCH2OHCH3H109←1)-β-D-GlcA-(6←OCH3)CH2OHCH3H110←1)-β-D-GlcACHOCH3H111←1)-β-D-GlcACHOCH3←1)-β-D-Glc112←1)-β-D-GlcCHOCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha113←1)-β-D-GlcACH2OHCH3←1)-β-D-Glc114←1)-β-D-GlcA-(6←OCH3)CH2OHCH3←1)-β-D-Glc115←1)-β-D-GlcCH2OHCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha116←1)-α-L-Ara-(2←1)-β-D-GlcCH2OHCH3H117←1)-α-L-AraCH2OHCH3←1)-β-D-Glc-(6←1)-β-D-Glc118←1)-α-L-Ara-(2←1)-β-D-GlcCH2OHCH3←1)-β-D-Glc-(6←1)-β-D-Glc119←1)-α-L-Rha-(2←1)-α-L-AraCH2OHCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha120←1)-α-L-AraCH2OHCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha121HCH2OHCOOH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha122HCOOHCH2OH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha123HCOOHCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha124HCHOCH2OH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha125HCHOCOOH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha126←1)-α-L-Ara-(2←1)-α-L-RhaCH2OHCH3H127←1)-α-L-Ara-(2←1)-α-L-Rha-(3←1)-β-D-XylCH2OHCH3H128←1)-α-L-Ara-(2←1)-α-L-Rha-(3←1)-α-L-AraCH2OHCH3H129←1)-α-L-Ara-(2←1)-α-L-RhaCH2OHCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha130←1)-α-L-Ara-(2←1)-α-L-Rha-(3←1)-β-D-XylCH2OHCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha131HCHOOH←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha132←1)-α-L-Ara-(2←1)-α-L-Rha-(3←1)-β-D-GlcHCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha133←1)-α-L-Ara-(2←1)-α-L-RhaHCH3←1)-β-D-Glc-(6←1)-β-D-Glc-(4←1)-α-L-Rha134←1)-β-D-GlcAHCH3←1)-β-D-Glc135←1)-β-D-GlcA-[(3←1)-β-D-Xyl]-(2←1)-β-D-GalOHCH2OH←1)-α-L-Ara-(2←1)-α-L-Rha-(4←1)-β-D-Xyl-(3←1)-β-D-Api136←1)-β-D-GlcA-(3←1)-β-D-Gal-(3←1)-β-D-GlcOHCH2OH←1)-β-D-Glc-(2←1)-α-L-Rha-[(3←1)-β-D-Api]-(4←1)-β-D-Xyl
圖1 三萜類化合物結構
二萜、倍半萜類化合物約20余種,如Acanthoic acid,Kaurenoic acid,ent-16β,17-Dihydroxy -(-) -kauran-19-oic acid,Acanthokoreoic acid A,Acanthol,(-)-Pimara-9(11),15-dien-19-ol-19- acetate,Noracanthopanin A,Acanthopanolide B,Andrographolide等,部分化合物結構見圖2[46-57]。
圖2 二萜及倍半萜類化合物結構
五加屬植物中不同的化學成分具有獨特的生物活性,大部分萜類成分在體外對胰脂肪酶、COX-1、β-葡萄糖醛酸酶、蛋白酪氨酸磷酸酶、組胺釋放和血小板聚集的活性具有較強抑制作用,還兼有一定的抑菌、殺蟲與溶血活性。萜類化合物表現(xiàn)出多種多樣的生物活性,如紫杉醇可治療多種癌癥,青蒿素可治療瘧疾,川楝素具有殺滅血吸蟲作用,穿心蓮內酯有抗上呼吸道感染的作用。白樺脂酸具有鎮(zhèn)咳、祛痰及選擇性抑制人型黑色素瘤細胞作用,并對HIV-1型感染、腦瘤、神經外胚層瘤、白血病、人型結腸癌等有一定的抑制作用。Silphioside F具有很強的殺傳播血吸蟲病Biomphalariaglabrata和Bulinusglobosus軟體動物的活性。Kalopanaxsaponin G有顯著的鎮(zhèn)靜作用,在1 mg/kg時能明顯降低小鼠的運動性[58-61]。Loniceroside C具有較強的溶血活性,對傳播血吸蟲病的蝸牛Biomphalariaglabrata具有強烈的殺軟體動物活性(<10mg/kg)等。
五加屬植物中的化學成分臨床應用與實用價值較大,已成為天然藥物研究的熱點領域。萜類被譽為天然抗生素藥物,臨床上主要用于肝炎、潰瘍、菌痢、肺炎、關節(jié)炎、高血壓、低血糖、腦膜炎、艾滋病、上呼吸道感染、鉤端螺旋體病、增強腎上腺皮質功能等疾病的治療,添加在化妝品中能減少頭皮屑和預防脫發(fā),分析上用于含量測定、鑒定、藥理實驗等標準品的制備[62-67]。
五加屬植物中的萜類化合物及其衍生物作為藥物和保健品,已廣泛用于中國民間醫(yī)學的營養(yǎng)治療,其相關資源分布、化學成分、波譜特征、生物活性、臨床應用等基礎研究已得到了重點關注,并取得了豐碩成果。同時,萜類化合物化學成分結構復雜,功能基因的表達量低,人工合成與分離純化困難,其開發(fā)利用受到限制。因此,研究萜類代謝合成途徑中參與的相關功能基因,有利于提高植物藥效,為新藥合成及其大規(guī)模生產奠定基礎。而且,隨著分子生物學的發(fā)展,藥用植物功能基因的克隆呈現(xiàn)快速增長的趨勢,分離和鑒定更多的萜類有用成分生物合成的關鍵酶及基因,實現(xiàn)目的成分在特定組織和細胞中的定向表達,提高中藥材品質,為天然藥用植物的品種選育、規(guī)范化種植及質量控制提供技術支撐。