Strigolactones are a novel class of plant hormones produced in roots and regulate shoot and root development. We have previously shown that synthetic strigolactone analogues potently inhibit growth of breast cancer cells and breast cancer stem cells. Here we show that strigolactone analogues inhibit the growth and survival of an array of cancer-derived cell lines representing solid and non-solid cancer cells including: prostate, colon, lung, melanoma, osteosarcoma and leukemic cell lines, while normal cells were minimally affected. Treatment of cancer cells with strigolactone analogues was hallmarked by activation of the stress-related MAPKs: p38 and JNK and induction of stress-related genes; cell cycle arrest and apoptosis evident by increased percentages of cells in the sub-G1 fraction and Annexin V staining. In addition, we tested the response of patient-matched conditionally reprogrammed primary prostate normal and cancer cells. The tumor cells exhibited significantly higher sensitivity to the two most potent SL analogues with increased apoptosis confirmed by PARP1 cleavage compared to their normal counterpart cells. Thus, Strigolactone analogues are promising candidates for anticancer therapy by their ability to specifically induce cell cycle arrest, cellular stress and apoptosis in tumor cells with minimal effects on growth and survival of normal cells.

In this work we report the synthesis of new fluorescent analogues of strigolactones, their spectroscopic properties and the evaluation of their biological activity both on seeds of Orobanche aegyptiaca and on the AM fungus Gigaspora margarita. The synthesis has been accomplished according to two different synthetic plans and allows the introduction of various substituents on the A and C rings of the framework, thus enabling access to bioactive molecules with different spectroscopic properties.

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Since the first report and due to its handiness and wide scope, the Suzuki-Miyaura (SM) cross coupling reaction has become a routine methodology in many laboratories worldwide. With respect to other common transition metal catalyzed cross couplings, the SM reaction has been so far less exploited as a tool to introduce an acyl function into a specific substrate. In this review, the various approaches found in the literature will be considered, starting from the direct SM acylative coupling to the recent developments of cross coupling between boronates and acyl chlorides or anhydrides. Special attention will be dedicated to the use of masked acyl boronates, alkoxy styryl and alkoxy dienyl boronates as coupling partners. A final section will be then focused on the acyl SM reaction as key synthetic step in the framework of natural products synthesis.

A new class of strigolactone analogues has been synthesized. They differ from known molecules, both of natural and synthetic origin, in two main features. The conjugated system extends from the enol ether bridge to the A ring, the B ring is a heterocycle while the C ring is a cyclic ketone instead of a g-lactone. The key step of the synthesis is a Nazarov cyclization on activated substrates. Bioassays using Orobanche seeds have revealed that all the molecules strongly stimulate germination; in particular the oxygen containing analogues are the most active. Interestingly, some of the new molecules show fluorescent properties.

Strigolactones are a class of natural and synthetic compounds that in the past decade have been exciting the scientific community not only for their intriguing biological properties but also for their potential applications in agriculture. These applications range from their use as hormones to modify and/or manage plant architecture, to their use as stimulants to induce seed germination of parasitic weeds and thus control their infestation by a reduced seed bank, to their use as 'biostimulants' of plant root colonisation by arbuscular mycorrhizal fungi, improving plant nutritional capabilities, to other still unknown effects on microbial soil communities. More recently, these compounds have also been attracting the interest of agrochemical companies. In spite of their biological attractiveness, practical applications are still greatly hampered by the low product yields obtainable by plant root exudates, by the costs of their synthesis, by the lack of knowledge of their off-target effects and by the not yet specified or properly identified legislation that could regulate the use of these compounds, depending on the agricultural purposes. The aim of this article is to discuss, in the light of current knowledge, the different scenarios that might play out in the near future with regard to the practical application of strigolactones. © 2016 Society of Chemical Industry.

The Pd-catalyzed coupling reaction of lactam or lactone-derived vinyl triflates and phosphates with alpha-alkoxydienylboronates gives conjugated alkoxytrienes in which one of the double bonds is embedded in a heterocyclic moiety. If subjected to mild acidic hydrolysis, these compounds undergo a 4pi electrocyclization process (Nazarov reaction) which furnishes cyclopenta-fused O- and N-heterocycles in good yields. The scope of the work has been that of closely examining the role and effect of both the heteroatom and the heterocycle ring size on the outcome of the electrocyclization, as well as the torquoselectivity of this process. The presence of the heteroatom was essential in stabilizing the oxyallyl cation intermediate, thus allowing the reaction to occur. The ring size was also a basic parameter in the cyclization step: five-membered azacycles required more drastic conditions to give 5-5 fused systems and did so only after an initial hydrolysis to the corresponding divinyl ketones. As for the torquoselectivity, with both 2-methyl and 4-methyl substituted lactam derivatives steric interactions seem to have a role in forcing the conrotatory process to take place in one sense only: allowing the synthesis of diastereomerically pure compounds to be realized. Because different patterns of substitution on the heterocycle are compatible with the reaction conditions, the methodology developed could be very useful for the synthesis of natural products and biologically active compounds containing cyclopenta-fused O- and N-heterocycle moieties.

Cannabis sativa active compounds are extensively studied for their therapeutic effects, beyond the well-known psychotropic activity. C. Sativa is used to treat different medical indications, such as multiple sclerosis, spasticity, epilepsy, ulcerative colitis and pain. Simultaneously, basic research is discovering new constituents of cannabis-derived compounds and their receptors capable of neuroprotection and neuronal activity modulation. The function of the various phytochemicals in different therapeutic processes is not fully understood, but their significant role is starting to emerge and be appreciated. In this review, we will consider the structure-activity relationship (SAR) of cannabinoid compounds able to bind to cannabinoid receptors and act as therapeutic agents in neuronal diseases, e.g., Parkinson’s disease.