Colaborative Research on Anti-HIV Triterpenoids

根据白桦酸(1)和二氢白桦酸(9)被确定为抗HIV药物的事实，合成了一系列羽扇豆烷型三萜酸衍生物，并评价了它们在急性感染H9细胞中抑制HIV-1复制的活性。其中，3-O-(3‘，3’-二甲基丁二酸基)-白桦酸(3)和3-O-(3‘，3’-二甲基丁二基)-二氢白桦酸(11)均表现出极强的抑制活性，EC_(50)和Gt；值为&lt；0.00035，体外治疗指数(TI)显著。值分别为&gt；20,000和&gt；14,000。3-O-(3‘，3’-二甲基戊二酰基)-白桦酸和-二氢白桦酸(12)、3-O-二甘醇-白桦酸和-二氢白桦酸和3-O-戊二酰白桦酸对HIV复制也有很强的抑制作用，ED50和TI.值分别为0.01~0.0023和1,017~2,344。此外，化合物11和12在单倍体…中也具有抗HLV复制的活性TE细胞系和n个外周血单核细胞(PBMC)。体外实验表明，这些化合物对HIV-1逆转录酶没有抑制作用，但在20-40µg/ml的浓度范围内完全抑制合胞体的形成。3-O-(2‘，2’-二甲基琥珀酰基)-白桦酸(2)对HIV诱导的膜融合也有抑制作用，IC_(100)为20mug/ml，但其抗HIV活性明显低于ED_(50)和T.L。值为5.9。这一观察结果表明，除了抑制合胞体的形成外，另一种作用机制(S)可能参与了这些化合物的抗艾滋病毒活性。化合物3在MAGI分析中没有活性，这表明它在病毒生命周期的后期阶段，如病毒蛋白质合成之后，抑制了HIV的复制。另一方面，齐墩果酸被从几种植物中鉴定为抗HIV的成分，包括月季(叶)、Prosopis glandulosa(叶和树枝)、黄柏(全植物)、棒花合欢(叶)、头状花序(全植物)和金钱草(地上部分)。抑制HIV-1在急性感染的H9细胞中的复制，其EC50为3.7um；抑制H9细胞的生长，IC50为47.8um[治疗指数(TI.)12.8]。从木犀草和大头菜中分离得到的蓬果酸也被鉴定为抗HIV药物(EC_&lt；50&gt；3.0UM，T.I.16.6)。虽然熊果酸确实具有抗HIV活性(EC_&lt；50&gt；4.4um)，但它有轻微的毒性(IC_&lt；50&gt；14.3um，T.I.3.3)。基于这些结果，我们检测了从几种植物中分离出的齐墩果酸或酚甲酸相关的三萜类化合物的抗HLV活性。此外，我们先前证明了白桦酸的衍生物，作为一种抗HIV的成分，从棒花链霉叶中分离出来，显示出极强的抗HIV活性。据此，我们制备了齐墩果酸的衍生物，并对其抗HIV活性进行了评价。在齐墩果酸衍生物中，3-O-(3‘，3’-二甲基琥珀酰基)齐墩果酸的抗HIV活性最强，EC_(50)和TI.值分别为0.00086和22,400。虽然熊果酸对H9细胞的毒性较小，但其抗HIV活性与齐墩果酸相当。此外，熊果酸的结构与齐墩果酸和白桦酸密切相关，因此被认为是一种潜在的抗HIV先导药物。因此，对类似的熊果酸进行修饰，并评价其抗HIV活性。3-O-二甘醇基尿酸显示了相对较强的抗艾滋病毒活性，其EC50和TI.值分别为0.31um和155.5。然而，包括3，3-二甲基丁二酸衍生物在内的其他衍生物的抗HJV活性不如相应的桦木酸和齐墩果酸衍生物。较少

A series of lupane-type triterpenoic acid derivatives were synthesized and evaluated for their inhibitory activity against HIV-1 replication in acutely infected H9 cells, based on the fact that betulinic acid (1) and dihydrobetulinic acid (9) were identified as anti-HIV agents. Among the derivatives, 3-O-(3 ', 3 '-dimethylsuccinyl)-betulinic acid (3) and 3-O-(3 ', 3 '-dimethyl-succinyl)-dihydrobetulinic acid (11) both demonstrated extremely potent inhibitory activity with EC_<50> values of< 0.00035 muM.They exhibited remarkable in vitro therapeutic index (TI.) values of >20,000 and >14,000, respectively. 3-O-(3', 3'-Dimethylglutaryl)-betulinic acid and -dihydrobetulinic acid(12), 3-O-diglycolyl-betulinic acid and -dihydrobetulinic acid and 3-O-glutaryl- betulinic acid were also potent inhibitors of HIV replication with ED_<50> values ranging from 0.01 to 0.0023 muM and T.I.values from 1,017 to 2,344. In addition, compounds 1 1 and 12 are also active against HLV replica-tion in a monocy … More te cell line and n peripheral blood mononuclear cells (PBMCs). Our in vitro assay indicated that these compounds are not inhibitors on HIV- 1 reverse transcriptase, whereas they inhibited syncytia formation completely in a concentration range of 20 - 40 mug/mL.However, 3-O-(2', 2'-dimethylsuccinyl)-betulinic acid (2) was also found to be an inhibitor of HIV-induced membrane fusion with IC_<100> value of 20mutg/mL, though it displayed significantly lower anti-HIV activity than foregoing compounds with ED_<50> value of 2.7 muM and T.l. values of 5.9. This observation indicated that another mechanism(s) of action other than inhibition of syncytia formation could be involved in the anti-HIV activity shown by these compounds. Compound 3 was not active in the MAGI assay, suggesting that it inhibit HIV replication at a late stage of the viral life cycle, such as after viral protein synthesis.On the other hand, oleanolic acid was identified as an anti-HIV principle from several plants, including Rosa woodsii (leaves), Prosopis glandulosa (leaves and twigs), Phorodendron juniperinum (whole plant), Syzygium claviflorum (leaves), Hyptis capitata (whole plant), and Terniroemia gymnanthera (aerial part). It inhibited HIV- 1 replication in acutely infected H9 cells with an EC_<50> value of 3.7 muM, and inhibited H9 cell growth with an IC_<50> value of 47.8 muM [therapeutic index (T.I.) 12.8]. Pomolic acid, isolated from R.woodsii and H.capitata, was also identified as an anti-HIV agent (EC_<50> 3.0 muM, T.I.16.6). Although ursolic acid did show anti-HIV activity (EC_<50> 4.4 muM), it was slightly toxic (IC_<50> 14.3 muM, T.I.3.3). Based on these results, we examined anti-HLV the activity of oleanolic acid- or pomolic acid-related triterpenes isolated from several plants. In addition, we previously demonstrated that derivatives of betulinic acid, isolated from the leaves of S.claviflum as an anti-HIV principle, exhibited extreme potent anti-HIV activity. Accordingly, we prepared derivatives of oleanolic acid, and evaluated their anti-HIV activity. Among the oleanolic acid derivatives, 3-O-(3', 3'-dimethylsuccinyl)-oleanolic acid demonstrated most potent anti-HIV activity, with an EC_<50> value of 0.00086 muM and a T.I.value of 22,400.Though ursolic acid is slightly toxic against H9 cells, it shows similar level of anti-HIV acitivity to that of oleanolic acid. In addition, the structure of ursolic acid is closely correlated with oleanolic acid and betulinic acid, hence it is regarded as a potential lead for anti-HIV agent. Therefore, similar modification of ursolic acid, and evaluated their anti-HIV activities. 3-O-diglycoryl-uroslic acid demonstarated relatively potent anti-HIV activity with an EC_<50> value of 0.31 muM and a T.I.value of 155.5. Hoever, anti-HJV activities for other derivatives, including 3,3-dimethysuccinyl derivative, were not potent as corresponding betulinic acid and oleanolic acid derivatives. Less