Natural Product Triterpenoids and Their Semi-Synthetic Derivatives with Potential Anticancer Activity.

Triterpenoids are distributed widely in higher plants and are of interest because of their structural diversity and broad range of bioactivities. In particular, there is a very large literature on the propensity of a variety of triterpenoids to act as potential anticancer agents. In the present review, the anticancer potential is summarized for naturally occurring triterpenoids and their semi-synthetic derivatives, including examples of lupane-, oleanane-, ursane-, and cucurbitane-type pentacyclic triterpenoids, along with dammarane-type tetracyclic triterpenes including ginsenosides and their sapogenins and dichapetalins, which have been characterized as antitumor leads from higher plants. Preliminary structure-activity relationships and reported mechanisms of the antineoplastic-related activity are included. Prior studies for triterpenoids of plant origin are supportive of additional work being conducted on the more detailed biological and mechanistic evaluation for the progression of this type of natural products as possible cancer chemotherapeutic agents.

Ren Y ，Kinghorn AD 《-》

Oleanane-, ursane-, and quinone methide friedelane-type triterpenoid derivatives: Recent advances in cancer treatment.

Natural pentacyclic triterpenoids (PTs) have been often reported to exhibit a wide range of biological activities. Among them, the anticancer and anti-inflammatory activities are the most studied. Over the last two decades, the number of publications reporting the anticancer effects of PTs has risen exponentially, reflecting the increasing interest in these natural products for the development of new antineoplastic drugs. Among of the most investigated PTs regarding their anticancer properties are oleanane-, ursane and friedelane-types, including oleanolic, glycyrrhetinic, ursolic and asiatic acids, and celastrol, among others. The extensive research in this field shows that the anticancer effects of PTs are mediated by several mechanisms, as they modulate a diverse range of molecular targets and signaling pathways, involved in cancer cell proliferation and survival. Considering the anticancer potential of this class of compounds, a number of semisynthetic derivatives has been synthetized aiming to improve their therapeutic activity and pharmacokinetic properties, and decrease their toxicity. Some of these new semisynthetic derivatives have shown improved anticancer activity in various cancer cell lines and animal models compared with the parent compound. Moreover, some of these compounds have been assessed in clinical trials, proving to be safe for human use. This review updates the most recent findings on the semisynthetic derivatives of oleanane-, ursane- and quinone methide friedelane-type PTs with anticancer activity. A brief introduction concerning the PTs and their anticancer activity is given, and the main semisynthetic modifications that have been performed between 2012 and early 2017 are reviewed and discussed.

Salvador JAR ，Leal AS ，Valdeira AS ，Gonçalves BMF ，Alho DPS ，Figueiredo SAC ，Silvestre SM ，Mendes VIS ... -  《-》

Known Triterpenes and their Derivatives as Scaffolds for the Development of New Therapeutic Agents for Cancer.

Plants produce several bioactive secondary metabolites whose are used as therapeutic agents to treat several diseases, among whom cancer. Triterpenes are secondary metabolites that exert inhibitory activity against multiple intracellular and extracellular targets in euchariotic cells. These targets are proteins involved in apoptosis, cell development and differentiation, angiogenesis, metastasis and inflammatory processes. The inhibition of their functions leads to decreased cellular growth, differentiation and migration, resulting in antitumor activity, as shown by several authors. Furthermore, during recent years synthetic triterpenoid derivatives have also been developed to implement potency and efficacy of starting compounds, allowing the obtainment of new agents having promising anticancer activity. In this review we report the latest results regarding anticancer activity of some of the most studied triterpenes in the field, as well as of their semi-synthetic derivatives, with the aim to summarize the role of triterpenes as molecular leads for the development of new classes of antitumor agents. We focused on the most recent literature regarding triterpenes in cancer treatment, highlighting the potential of developing new drugs starting from these natural compounds. Several "old" triterpenes as ursolic, betulinic and oleanolic acids were recently reconsidered as model compounds for the development of innovative anticancer agents. Their activity against proteins involved in tumor development enhances the opportunity to exploit these compounds as new multi-target therapeutic agents. Furthermore, the possibility to synthetize new compounds from their natural-occurring structures could be an alternative to overcome cellular resistance to drugs and could improve their therapeutic efficacy.

Peron G ，Marzaro G ，Dall Acqua S 《-》

Plant-derived triterpenoids as potential antineoplastic agents.

Setzer WN ，Setzer MC 《MINI-REVIEWS IN MEDICINAL CHEMISTRY》

Recent Advances in Antiviral Activities of Triterpenoids.

Liu Y ，Yang L ，Wang H ，Xiong Y ... -  《Pharmaceuticals》