Discovery of a nitroaromatic nannocystin with potent in vivo anticancer activity against colorectal cancer by targeting AKT1.

The development of targeted chemotherapeutic agents against colorectal cancer (CRC), one of the most common cancers with a high mortality rate, is in a constant need. Nannocystins are a family of myxobacterial secondary metabolites featuring a 21-membered depsipeptide ring. The in vitro anti-CRC activity of natural and synthetic nannocystins was well documented, but little is known about their in vivo efficacy and if positive, the underlying mechanism of action. In this study we synthesized a nitroaromatic nannocystin through improved preparation of a key fragment, and characterized its in vitro activity and in vivo efficacy against CRC. We first described the total synthesis of compounds 2-4 featuring Heck macrocyclization to forge their 21-membered macrocycle. In a panel of 7 cancer cell lines from different tissues, compound 4 inhibited the cell viability with IC values of 1-6 nM. In particular, compound 4 (1, 2, 4 nM) inhibited the proliferation of CRC cell lines (HCT8, HCT116 and LoVo) in both concentration and time dependent manners. Furthermore, compound 4 concentration-dependently inhibited the colony formation and migration of CRC cell lines. Moreover, compound 4 induced cell cycle arrest at sub-G1 phase, apoptosis and cellular senescence in CRC cell lines. In three patient-derived CRC organoids, compound 4 inhibited the PDO with IC values of 3.68, 28.93 and 11.81 nM, respectively. In a patient-derived xenograft mouse model, injection of compound 4 (4, 8 mg/kg, i.p.) every other day for 12 times dose-dependently inhibited the tumor growth without significant change in body weight. We conducted RNA-sequencing, molecular docking and cellular thermal shift assay to elucidate the anti-CRC mechanisms of compound 4, and revealed that it exerted its anti-CRC effect at least in part by targeting AKT1.

Heck Macrocyclization in Forging Non-Natural Large Rings including Macrocyclic Drugs.

The intramolecular Heck reaction is a well-established strategy for natural product total synthesis. When constructing large rings, this reaction is also referred to as Heck macrocyclization, which has proved a viable avenue to access diverse naturally occurring macrocycles. Less noticed but likewise valuable, it has created novel macrocycles of non-natural origin that neither serve as nor derive from natural products. This review presents a systematic account of the title reaction in forging this non-natural subset of large rings, thereby addressing a topic rarely covered in the literature. Walking through two complementary sections, namely (1) drug discovery research and (2) synthetic methodology development, it demonstrates that beyond the well-known domain of natural product synthesis, Heck macrocyclization also plays a remarkable role in forming synthetic macrocycles, in particular macrocyclic drugs.

Anticancer Small-Molecule Agents Targeting Eukaryotic Elongation Factor 1A: State of the Art.

Eukaryotic elongation factor 1A (eEF1A) canonically delivers amino acyl tRNA to the ribosomal A site during the elongation stage of protein biosynthesis. Yet paradoxically, the oncogenic nature of this instrumental protein has long been recognized. Consistently, eEF1A has proven to be targeted by a wide assortment of small molecules with excellent anticancer activity, among which plitidepsin has been granted approval for the treatment of multiple myeloma. Meanwhile, metarrestin is currently under clinical development for metastatic cancers. Bearing these exciting advances in mind, it would be desirable to present a systematic up-to-date account of the title topic, which, to the best of our knowledge, has thus far been unavailable in the literature. The present review summarizes recent advances in eEF1A-targeting anticancer agents, both naturally occurring and synthetically crafted, with regard to their discovery or design, target identification, structure-activity relationship, and mode of action. Their structural diversity and differential eEF1A-targeting mechanisms warrant continuing research in pursuit of curing eEF1A-driven malignancy.

Functional verification of the JmLFY gene associated with the flowering of Juglans mandshurica Maxim.

In this study, a pBI121-JmLFY plant expression vector was constructed on the basis of obtaining the full-length sequence of the JmLFY gene from Juglans mandshurica, which was then used for genetic transformation via Agrobacterium inflorescence infection using wild-type Arabidopsis thaliana and lfy mutants as transgenic receptors. Seeds of positive A. thaliana plants with high expression of JmLFY were collected and sowed till the homozygous T3 regeneration plants were obtained. Then the expression of flowering-related genes (AtAP1, AtSOC1, AtFT and AtPI) in T3 generation plants were analyzed and the results showed that JmLFY gene overexpression promoted the expression of flowering-related genes and resulted in earlier flowering in A. thaliana. The A. thaliana plants of JmLFY-transformed and JmLFY-transformed lfy mutants appeared shorter leaves, longer fruit pods, and fewer cauline leaves than those of wild-type and the lfy mutants plants, respectively. In addition, some secondary branches in the transgenic plants converted into inflorescences, which indicated that the overexpression of JmLFY promoted the transition from vegetative growth to reproductive growth, and compensate the phenotypic defects of lfy mutant partially. The results provides a scientific reference for formulating reasonable genetic improvement strategies such as shortening childhood, improving yield and quality, and breeding desirable varieties, which have important guiding significance in production.

Site-directed late-stage diversification of macrocyclic nannocystins facilitating anticancer SAR and mode of action studies.

Nannocystins are a family of 21-membered cyclodepsipeptides with excellent anticancer activity. However, their macrocyclic architecture poses a significant challenge to structure modification. Herein, this issue is addressed by leveraging the strategy of post-macrocyclization diversification. In particular, a novel serine-incorporating nannocystin was designed so that its appending hydroxyl group could diversify into a wide variety of side chain analogues. Such effort facilitated not only structure-activity correlation at the subdomain of interest, but also the development of a macrocyclic coumarin-labeled fluorescence probe. Uptake experiments indicated good cell permeability of the probe, and endoplasmic reticulum was identified as its subcellular localization site.

Combining near infrared spectroscopy with predictive model and expertise to monitor herb extraction processes.

Albeit extensively utilized, herb extraction process (HEP) is hard to be monitored because of its batch nature and the fluctuating quality of raw materials. Process analytical tools like near infrared spectroscopy (NIRS) can offer nondestructive examinations and collect abundant data of the process, which in principle contain the information about the quality of both the product and the process itself. However, extra effort is often required for the data mining of such process measurements, and extracting knowledge of the quality of process can be even harder. In this study, we take the extraction process of licorice as a typical HEP instance, and combine NIRS with classical partial least squared regression (PLSR) and expertise for its on-line monitoring. We show that our scheme effectively extracts information with clear physical meanings, through which we can even uncover the process fault that does not induce evident abnormalities in the product quality. Moreover, the constructed model can continuously evolve with more process data from daily operations, and the idea of the whole framework can be directly generalized to other HEP.