Nitrogen-containing andrographolide derivatives with multidrug resistance reversal effects in cancer cells.

Multidrug resistance (MDR) remains a challenging issue in cancer treatment. Aiming at finding anticancer agents to overcome MDR, the triacetyl derivative (2) of the labdane diterpenoid lactone andrographolide (1) underwent the Michael-type addition reaction followed by elimination, yielding twenty-three new derivatives, bearing nitrogen-containing substituents (3-25). Their structures were assigned, mainly, by 1D and 2D NMR experiments.

Unlocking the Potential of Bio-Based Nitrogen-Rich Furanic Platforms as Biomass Synthons.

The demand for new biomass-derived fine and commodity chemicals propels the discovery of new methodologies and synthons. Whereas furfural and 5-hydroxymethylfurfural are cornerstones of sustainable chemistry, 3-acetamido-5-acetyl furan (3A5AF), an N-rich furan obtained from chitin biomass, remains unexplored, due to the poor reactivity of the acetyl group relative to previous furanic aldehydes. Here we developed a reactive 3-acetamido-5-furfuryl aldehyde (3A5F) and demonstrated the utility of this synthon as a source of bio-derived nitrogen-rich heteroaromatics, carbocycles, and as a bioconjugation reagent.

Design, synthesis, and biological evaluation of new arjunolic acid derivatives as anticancer agents.

Arjunolic acid (AA) is a pentacyclic triterpenoid with promising anticancer properties. A series of novel AA derivatives containing a pentameric A-ring with an enal moiety, combined with additional modifications at C-28, were designed and prepared. The biological activity on the viability of human cancer and non-tumor cell lines was evaluated in order to identify the most promising derivatives.

: phytochemistry and pharmacological potential of a gifted species.

L. (Cucurbitaceae), frequently named balsam apple, southern balsam pear or African pumpkin, is a vegetable with high nutritional value, being mostly used as food in sub-Saharan Africa. It has also been largely used in traditional medicine to treat several diseases, such as malaria fevers and diabetes.

Overcoming Multidrug Resistance: Flavonoid and Terpenoid Nitrogen-Containing Derivatives as ABC Transporter Modulators.

Multidrug resistance (MDR) in cancer is one of the main limitations for chemotherapy success. Numerous mechanisms are behind the MDR phenomenon wherein the overexpression of the ATP-binding cassette (ABC) transporter proteins P-glycoprotein (P-gp), breast cancer resistance protein (BCRP) and multidrug resistance protein 1 (MRP1) is highlighted as a prime factor. Natural product-derived compounds are being addressed as promising ABC transporter modulators to tackle MDR.

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.

Synthesis and anticancer activity of novel fluorinated asiatic acid derivatives.

A series of novel fluorinated Asiatic Acid (AA) derivatives were successfully synthesized, tested for their antiproliferative activity against HeLa and HT-29 cell lines, and their structure activity relationships were evaluated. The great majority of fluorinated derivatives showed stronger antiproliferative activity than AA in a concentration dependent manner. The most active compounds have a pentameric A-ring containing an α,β-unsaturated carbonyl group.

Ursane-type pentacyclic triterpenoids as useful platforms to discover anticancer drugs.

This review highlights the potential of natural and semisynthetic ursane-type triterpenoids as candidates for the design of multi-target bioactive compounds, with focus on their anticancer effects. A brief illustration of the biosynthesis, sources, and general biological effects of the main classes of naturally occurring pentacyclic triterpenoids (PTs) are provided.