Cytotoxic and Apoptosis-Inducing Activities, and Anti-Tumor-Promoting Effects of Cyanogenated and Oxygenated Triterpenes

Progress Toward the Asymmetric de Novo Synthesis of Lanostanes: A Counter Biomimetic Cucurbitane-to-Lanostane Type Transformation

An oxidative rearrangement has been established that enables a cucurbitane-to-lanostane type rearrangement that is counter to known biomimetic transformations that proceed in an opposite direction by way of a lanostane-to-cucurbitane transformation. Here, an oxidative dearomatization/Wagner-Meerwein rearrangement with a substrate bearing the characteristic cucurbitane triad of quaternary centers at C9, C13 and C14, and possessing an alkene at C11-C12, proceeds in a manner that selectively shifts the methyl group at C9 to C10 in concert with the establishment of a sterically hindered allylic cation. The major product isolated from this transformation is formed by trapping of the allylic cation by addition of acetate to C12, rather than termination of the cascade by loss of a proton at C8. While proceeding by way of a unique sequence of bond-forming reactions that begins by oxidative dearomatization, this process achieves what we believe is an unprecedented cucurbitane-to-lanostane transformation, generating a product that contains the characteristic lantostane triad of quaternary centers at C10, C13 and C14 while also delivering a functionalized C-ring.

Toward the Asymmetric de Novo Synthesis of Lanostanes: Construction of 7,11-Dideoxy-Δ5-lucidadone H

Efforts to establish an asymmetric entry to hexanorlanostanes has resulted in a concise synthesis of 7,11-dideoxy-Δ5-lucidadone H from epichlorohydrin. By exploiting metallacycle-mediated annulative cross-coupling (to establish a functionalized hydrindane) and stereoselective formation of the steroidal C9-C10 bond to establish a stereodefined 9-alkyl estrane, 14 subsequent steps have been established to generate a hexanorlanostane system. Key transformations include formal inversion of the C13 quaternary center, oxidative dearomatization/group-selective Wagner-Meerwein rearrangement, and Lewis acid mediated semi-Pinacol rearrangement.

A review on traditional usages, chemical constituents and pharmacological activities of periploca forrestii schltr

ETHNOPHARMACOLOGICAL RELEVANCE

Periploca forrestii Schltr. was listed as a classical medicinal plant in "Miao medicine", which is a branch of traditional Chinese medicine (TCM). According to the theory of TCM, P. forrestii has the efficacy of relaxing tendons and activating collaterals, and dispelling wind and eliminating dampness. Hence, it was often used for the therapy of rheumatoid arthritis and traumatic injury in clinical practice.

AIMS OF THE REVIEW

This review aims to present comprehensive information for the research progress of P. forrestii. The researches on botany, traditional uses, phytochemistry, pharmacology and toxicology of the plant are summarized. We mainly focus on the phytochemical and pharmacological investigations. As a representative class of phytochemicals in P. forrestii, more attention is paid to cardiac glycosides. The insights into potential action of mechanisms and possible future studies on P. forrestii are also discussed.

MATERIALS AND METHODS

Relevant literature was acquired from scientific databases including Google Scholar, Web of Science, Scifinder, Baidu Scholar, PubMed and Chinese national knowledge infrastructure. Monographs and Chinese pharmacopoeia were also utilized as references.

RESULTS

To date, all kinds of phytochemical constituents have been isolated and identified from this plant including cardiac glycosides, steroids, terpenoids, flavonoids, phenylpropanoids, quinones, organic phenolic acids and others. Among these, cardiac glycosides were considered as the major ingredients and bioactive materials. Modern pharmacological studies demonstrated that the plant possessed extensive bioactivity, such as anti-inflammatory and analgesic effects, immunosuppressive action, wound healing activity, antioxidant, anti-tumor and, cardiotonic properties.

CONCLUSIONS

As an important medicinal plant, lots of studies have proved that P. forrestii has significant therapeutical effects, especially on rheumatoid arthritis and traumatic injury. These results provide modern scientific evidence for traditional use and contribute to the development of novel remedies for chronic diseases. However, the exact mechanism of action remains to be elucidated. Furthermore, the long-term in vivo toxicity and clinical efficacy also require in-depth exploration in the future.