Munronin O, a potential activator for plant resistance.

A series of limonoids (1-8) were isolated from the whole plant of Munronia henryi and antiviral activities of the compounds were evaluated. The bioassay results demonstrated that Munronin O (1) showed remarkable protective activity and compounds 7 and 8 showed significant inactivating, protective, and curative activities against tobacco mosaic virus (TMV). With a 50% effective concentration (EC50) value of 91.5 µg/mL, compound 1 exhibited the best protective activity compared with ningnanmycin (192.3 µg/mL). The potential for these compound of inducing systemic acquired resistance (SAR) was also evaluated, and compound 1 showed excellent induction activities. Furthermore, it was found that potentiation of defense-related enzyme activity and the contents of SA was increased. Compound 1 could also inhibit the expression of TMV CP and up-regulate the expression of defense-related genes. This work revealed that compound 1 can induce resistance and enhance plant tolerance to TMV infection. Hence, compound 1 can be considered as a potential activator for inducing plant resistance.

Identification of Ingol and Rhamnofolane Diterpenoids from Euphorbia resinifera and Their Abilities to Induce Lysosomal Biosynthesis.

The phytochemical study of Euphorbia resinifera afforded 18 structurally diverse diterpenoids, including 14 new ingol-type diterpenoids, euphorblins A-N (1-14), a new rhamnofolane diterpenoid, euphorblin O (15), and three known analogues (16-18). The structures of these compounds were deduced using 2D NMR spectroscopy and NOE experiments. The structure of compound 1 was confirmed by single-crystal X-ray crystallography. The abilities of the compounds to enhance lysosomal biosynthesis were evaluated through LysoTracker Red staining. Among the 10 active compounds, compounds 2, 4, and 18 showed remarkable immunofluorescence strength, and their LysoTracker staining intensities were 155.9%, 143.5%, and 140.7%, respectively, greater than that of the control. A series of lysosomal genes were also found to be upregulated by these compounds, which further confirms their ability to induce lysosome biosynthesis and suggests that these diterpenoids have potential as lead compounds for the development of drugs for the treatment of lysosome-related diseases.

Inhibitory Effects of Constituents from the Aerial Parts of Rosmarinus officinalis L. on Triglyceride Accumulation.

Sixteen flavonoids (1-16) including two new ones, named officinoflavonosides A (1) and B (2) were obtained from the aerial parts of Rosmarinus officinalis. Among the known ones, 6, 10, and 13 were isolated from the rosmarinus genus for the first time. Their structures were elucidated by chemical and spectroscopic methods. Moreover, the effects on sodium oleate-induced triglyceride accumulation (TG) in HepG2 cells of the above-mentioned compounds and 16 other isolates (17-32) reported previously to have been obtained in the plant were analyzed. Results show that eight kinds of flavonoids (compounds 1, 2, 3, 6-9 and 11) and seven kinds of other known isolates (compounds 17-20, 23, 26 and 31) possessed significant inhibitory effects on intracellular TG content in HepG2 cells. Among them, the activities of compounds 1 and 20 were comparable to that of orlistat, which suggested that these compounds in this plant might be involved in lipid metabolism.

New terpenoid glycosides obtained from Rosmarinus officinalis L. aerial parts.

Five new terpenoid glycosides, named as officinoterpenosides A1 (1), A2 (2), B (3), C (4), and D (5), together with 11 known ones, (1S,4S,5S)-5-exo-hydrocamphor 5-O-ß-D-glucopyranoside (6), isorosmanol (7), rosmanol (8), 7-methoxyrosmanol (9), epirosmanol (10), ursolic acid (11), micromeric acid (12), oleanolic acid (13), niga-ichigoside F1 (14), glucosyl tormentate (15), and asteryunnanoside B (16), were obtained from the aerial parts of Rosmarinus officinalis L. Their structures were elucidated by chemical and spectroscopic methods (UV, IR, HRESI-TOF-MS, 1D and 2D NMR). Among the new ones, 1 and 2, 3 and 4 are diterpenoid and triterpenoid glycosides, respectively; and 5 is a normonoterpenoid. For the known ones, 6 was isolated from the Rosmarinus genus first, and 15, 16 were obtained from this species for the first time.