The discovery of novel, effective, and botanical pesticides is one of the main strategies for modern plant protection and insect pest control. During the search for novel botanical pesticides from natural sources, the seeds of Sophora tonkinensis were systematically investigated to obtain 11 new matrine-type alkaloids (1–11), including one novel matrine-type alkaloid featuring an unprecedented 5/6/6/6 tetracyclic skeleton (1), along with 16 known compounds (12–27). Their structures were elucidated by comprehensive spectroscopic data analysis (IR, UV, NMR, and HRESIMS), ECD calculations, and single-crystal X-ray diffraction. The anti-tobacco mosaic virus (TMV) activity and insecticidal activities against Aphis fabae and Tetranychus urticae of the compounds were also respectively screened using the half-leaf method and spray method. Biological tests indicated that compounds 2, 4, 6, and 26 displayed significant anti-TMV biological activities compared with the positive control ningnanmycin. Compounds 7, 17, and 26 presented moderate activities against A. fabae with LC50 values of 38.29, 18.63, and 23.74 mg/L, respectively. Moreover, compounds 13 and 26 exhibited weak activities against T. urticae.

No abstract

Vulgarisin A (1), a new diterpenoid with an unprecedented 5/6/4/5 fused tetracyclic ring skeleton, has been isolated from the medicinal plant Prunella vulgaris Linn. Its structure was characterized by extensive spectroscopic methods, and the absolute configuration was secured by single crystal X-ray diffraction analysis. Compound 1 showed weak cytotoxicity against human lung carcinoma A549 cells with an IC50 value of 57.0 μM.

No abstract

Two novel polycyclic polyprenylated acylphloroglucinols (PPAPs), hyperfols A (1) and B (2), and two known biosynthetically related precursors (3 and 4) were isolated from Hypericum perforatum. Compound 1 possesses an unprecedented 2,3-seco-PPAP with a fused 5/5/9/5 tetracyclic skeleton, and 2 features a 30-norPPAP. Their structures were established by spectroscopic analysis, computer-assisted structure elucidation software, and electronic circular dichroism calculations. Moreover, compounds 1 and 4 exhibit significant cytotoxicity against human erythroleukemia cells by inducing cell apoptosis.

No abstract

This study reports a novel class of inhibitors of uridine 5'-diphosphate (UDP) galactopyranose mutase (UGM) derived from a screening of natural products. This enzyme is an essential biocatalyst involved in the cell wall biosynthesis of Mycobacterium tuberculosis. Flavonoids are potent inhibitors of UGM. The synthesis of novel methylated flavonoids allowed a structure-activity relationship analysis to be performed and which functional groups and structural elements were required for UGM inhibition could be determined. The binding mode of one of the best inhibitors was found to be noncompetitive. Docking simulations indicated that this molecule was likely to bind UGM in its open conformation, in a cavity recently identified as a "druggable" pocket. Importantly, two of the best inhibitors of the M. tuberculosis UGM displayed moderate activity against whole M. tuberculosis cells. This study reports the first natural products that act as inhibitor of UGM. Given the importance of natural products in medicinal chemistry, these results create new opportunities for the discovery of new antitubercular agents.

Twenty-four 14-sulfonamide-tetrandrine derivatives as potential anti-cancer agents were synthesized. The synthetic derivatives were investigated for their cytotoxic activity against human cancer cell lines MDA-MB-231, PC3, WM9, HEL and K562. Initially, the IC values (50% inhibitory concentrations) of all of the compounds were determined. These derivatives exhibited potent, but distinct, inhibitory effects on the above-mentioned cell lines. Among them, compound , which was modified with a 2-naphthalenesulfonyl group at the 14-amino position, showed impressive inhibition of all five cancer cell lines, and especially of MDA-MB-231 cells with an IC value of 1.18 ± 0.14 μM. Further mechanism exploration showed that induced potent apoptotic cell death on MDA-MB-231 cancer cells in a concentration-dependent manner. The results revealed that might be a potential anti-cancer drug candidate.