A short total synthesis of bioactive alkaloid calothrixin B have been accomplished with atom and step economy from commercially available starting materials. The key cyclization involved a Baylis−Hillman/6π electrocyclization/dehydroaromatiz‐ation sequence to construct the pentacyclic skeleton. Reduction of the resulting lactam followed by oxidation led to the characteristic quino[4,3‐b]carbazole framework. This intermediate underwent a direct oxidation with high regioselectivity to yield the final product.magnified image

The tetracyclic and pentacyclic skeletons of pyrido and quinolinocarbazole alkaloids have been synthesized via a unified strategy.

An unexpected cascade reaction is developed for the construction of functionalized 3-bis(indol-3-yl)methylquinoline-2(1H)-ones. Three C–C bonds and one ring are created in one pot triggered by Pd-catalyzed C-3 alkenylation of indole with 2-acyl-N-acrylaniline derivatives. A series of complex and specific quinoline-2(1H)-ones were produced, most of them showed significant α-glucosidase inhibitory activities.

Chronic myeloid leukemia (CML) accounts for a major cause of death in adult leukemia patients due to mutations or other reasons for dysfunction in the ABL proto-oncogene. The ubiquitous BCR–ABL expression stimulates CML by activating CDK1 and cyclin B1, promoting pro-apoptotic, and inhibiting antiapoptotic marker expression along with regulations in RAS pathway activation. Thus, inhibitors of cyclins and the RAS pathway by ERK are of great interest in antileukemic treatments. Mikanolide is a sesquiterpene dilactone isolated from several Asteraceae family Mikania sp. plants. Sesquiterpene dilactone is a traditional medicine for treating ailments, such as flu, cardiovascular diseases, bacterial infections, and other blood disorders. It is used as a cytotoxic agent as well. The need of the hour is potent chemotherapeutic agents with cytotoxic effects inhibition of proliferation and activation of apoptotic machinery. Recently, ERK inhibitors are used in clinics as anticancer agents. Thus, in this study, we synthesized 22-mikanolide derivatives that elucidated to be potent antileukemic agents in vitro. However, a bioactive mikanolide derivative, 3g, was found with potent antileukemic activity, through the Ras/Raf/MEK/ERK pathway. It can arrest the cell cycle by inhibiting phosphorylation of CDC25C, triggering apoptosis, and promoting DNA and mitochondrial damage, thus suggesting it as a potential chemotherapeutic agent for leukemia patients.