Anti-TMV Effects of Amaryllidaceae Alkaloids Isolated from the Bulbs of Lycoris radiata and Lycoricidine Derivatives.

Fifteen known amaryllidaceae alkaloids were isolated from the bulbs of Lycoris radiata. Some of the compounds and lycoricidine derivatives had been screened for the activities against tobacco mosaic virus (TMV) by the conventional half-leaf method. Lycoricidine derivatives were also carried out the assay of effect on systemic infection of TMV by western-blot and RT-PCR analysis. The tested compounds showed moderate inactivation effect, whereas the lycoricidine derivatives showed good protective effect. The protective inhibitory activity of compounds L1 (N-methyl-2,3,4-trimethoxylycoricidine) (60.8%) and L3 (N-methyl-2-methoxy-3,4-acetonidelycoricidine) (62.0%) was almost similar to the positive control, Ningnanmycin (66.4%). RT-PCR and Western-blot analysis displayed that compounds L1, L3, L5 (N-allyl-2,3,4-triallyloxylycoricidine) exhibited antiviral activity, which was evidenced by reducing TMV-CP gene replication and TMV-CP protein expression. Additionally, defensive enzyme activities confirmed that compound L1 could increase the activity of PAL, POD, SOD to improve disease resistance of tobacco.

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.