1,3,4-Oxadiazole Contained Sesquiterpene Derivatives: Synthesis and Microbiocidal Activity for Plant Disease

Abstract

A series of 1,3,4-oxadiazole contained sesquiterpene derivatives were synthesized, and the activity of the target compounds against Xanthomonas oryzae pv. oryzae (Xoo), Xanthomonas axonopodis pv. citri (Xac), and tobacco mosaic virus (TMV) were evaluated. The biological activity results showed that the EC50 values of compounds H4, H8, H11, H12, H14, H16, and H19 for Xac inhibitory activity were 33.3, 42.7, 56.1, 74.5, 37.8, 43.8, and 38.4 μg/ml, respectively. Compounds H4, H8, H15, H19, H22, and H23 had inhibitory effects on Xoo, with EC50 values of 51.0, 43.3, 43.4, 50.5, 74.6, and 51.4 μg/ml, respectively. In particular, the curative and protective activities of compound H8 against Xoo in vivo were 51.9 and 49.3%, respectively. In addition, the EC50 values of the inactivation activity of compounds H4, H5, H9, H10, and H16 against TMV were 69.6, 58.9, 69.4, 43.9, and 60.5 μg/ml, respectively. The results of molecular docking indicated that compound H10 exhibited a strong affinity for TMV-coat protein, with a binding energy of −8.88 kcal/mol. It may inhibit the self-assembly and replication of TMV particles and have an anti-TMV effect, which supports its potential usefulness as an antiviral agent.

Design, Synthesis, and Bioactivity of Spiro Derivatives Containing a Pyridine Moiety

“…TMV-CP plays an essential role in the replication and assembly of plant viruses. 44 According to our docking results, compounds E20 and F4 exhibited high affinities for TMV-CP and their binding energies (−6.7 and −6.4 kcal/mol, respectively) were lower than Ningnanmycin (−6.3 kcal/ mol). Compound E20 had hydrophobic interactions with amino acids ILE93, ASN91, GLN38, ARG92, PRO102, ASN101, THR107, VAL96, ARG90, and GLU95 (Figure 4A,A′), while compound F4 formed hydrophobic interactions with GLN38, ARG90, ASN91, VAL96, ARG92, and ASN101 (Figure 4C,C′).…”

“…TMV-CP plays an essential role in the replication and assembly of plant viruses . According to our docking results, compounds E20 and F4 exhibited high affinities for TMV-CP and their binding energies (−6.7 and −6.4 kcal/mol, respectively) were lower than Ningnanmycin (−6.3 kcal/mol).…”

Hydrazone modification of non-food natural product sclareolide as potential agents for plant disease

“…The synthetic route of the title compounds Z1–Z30 is shown in Scheme 1 , in which the synthesis of the hydrazide intermediate 1 was described in our previous articles [ 30 ]. In the basic steps in the literature [ 40 , 41 ], after intermediate 1 was dissolved in absolute ethanol, different aldehydes were added continuously, and the target compounds Z1–Z30 were acquired after the reaction was completed.…”

“…According to the general procedure in the literature [ 40 ], and the detailed synthesis procedure of intermediate 1 in our previous article [ 30 ]. A brief description of its synthesis was given, where the natural product sclareolide (500 mg, 1 mol) and hydrazine hydrate (1 mL, 11 mol) reacted by hydrazinolysis under absolute ethanol, and the precipitate collected after the treatment was intermediate 1 .…”

“…Sesquiterpenes and their derivatives possess unique biological properties for the control of insects [ 21 ], fungi/bacteria [ 22 , 23 ], viruses [ 24 , 25 ], inflammations [ 26 ], and sesquiterpene lactones antimalarial effect of artemisinin [ 27 ]. In particular, the sesquiterpenoids isolated [ 28 , 29 ] and reported in our previous study [ 30 ] have good activity against TMV and are of great research value in commercial applications.…”