Semisynthesis and Antifeedant Activity of New Derivatives of a Dihydro-β-Agarofuran from Parnassia wightiana

Abstract

Five new derivatives (2–6) were semi-synthesized using compound 1, a dihydro-β-agarofuran sesquiterpene with C-2 ketone obtained from Parnassia wightiana, as the starting material by acylation, oxidation, reduction, esterification, and amination, respectively. Structures of 2–6 were confirmed by 1D- and 2D-NMR and HR-ESI-MS spectra. In addition, antifeedant activities of these compounds (1–6) were tested against the 3rd-instar larvae of Mythimna separata. Antifeedant effects of compounds 2 and 4 were greater than the parent compound 1 whereas other compounds exhibited low to no feeding deterrent effects against third instar M. separata larvae in lab bioassays. Therefore, our results suggest that acylated and reduced derivatives at C-8 and C-2, respectively, of 1 may improve the antifeeding effect. This preliminary information will be useful in designing new insect control agents against M. separata and other important pests.

Soluble Epoxide Hydrolase Inhibitory and Anti-inflammatory Components from the Leaves ofEucommia ulmoidesOliver (Duzhong)

“…Methanolic extracts of E. ulmoides leaves were found to inhibit the growth of Propionibacterium acnes. 58 In addition, the 16 duzhong extracts also reduced the secretion of pro-inflammatory cytokines, such as TNF-,…”

“…19 We examined the inhibitory effect of (22), 38 asperulosidic acid (23), 39 a mixture of blumenol C and 9-epi-blumenol C (24), 40 foliasalacioside B1 (25), 41 foliasalacioside E2 (26), 42 and icariside F2 (27) 43 (Figure 1). Structure types of these compounds include flavonoids (1-9), phenylpropanoids (10)(11)(12)(13)(14), lignans (15)(16)(17)(18), iridoids (19)(20)(21)(22)(23), and megastigmanes (24)(25)(26). Among these, compounds 11, 26 and 27 have been obtained from E. ulmoides for the first time.…”

Three Sesquiterpenoid Dimers from Chloranthus japonicus: Absolute Configuration of Chlorahololide A and Related Compounds

“…As part of our ongoing search for new bioactive natural products from the traditional Chinese herbal medicines in the Qinba Mountains, a chemical study of the whole plant of C . japonicus was carried out, leading to the discovery of a new sesquiterpenoid dimer, named multistalide C ( 1 ), together with two known compounds, shizukaols C and D ( 2 and 3 ) (Chart ).…”

“…Multistalide C (1): colorless oil; [α] D 23 = À165.5 (c = 1.5 in MeOH); 1 H NMR and 13 C NMR (see Table 1…”

“…[6][7][8][9] Some of them were reported to show multibiological activities, such as antifungal, potent and selective tumor growth-inhibitory, inhibition of cell adhesion molecule expression, and of tyrosinase. [10][11][12] As part of our ongoing search for new bioactive natural products from the traditional Chinese herbal medicines in the Qinba Mountains, [13][14][15][16][17] a chemical study of the whole plant of C. japonicus was carried out, leading to the discovery of a new sesquiterpenoid dimer, named multistalide C (1), together with two known compounds, shizukaols C and D (2 and 3) (Chart 1). Herein, we describe the isolation, structural identification, including the absolute configuration, and brine shrimp larvae toxicity of the three compounds.…”