New 8-O-4′ Neolignans and Their Antibacterial Activity from the Whole Plants of Clematis lasiandra

Abstract

Four new 8-O-4′ neolignans, characterized at methoxy or ethoxy groups substituted at C-7, namely, (±) lasiandranins A–D ( 1 – 4 ), and two known analogs (±) pinnatifidanin BV ( 5 ) and (±) pinnatifidanin BVI ( 6 ) were isolated from the whole plants of Clematis lasiandra Maxim. The structures of 1 – 6 were determined by spectroscopic methods including 1D, 2D NMR, ECD, and HRESIMS analysis. Compounds 1 and 5 were determined as erythro configuration, while 2 – 4 and 6 were determined as threo configuration based on the chemical shift difference of H-9a and H-9b in CD 3 OD. The 8-O-4′ neolignans were found from the genus Clematis for the first time. Compounds 1 – 6 were evaluated for their antibacterial activity against three plant pathogenic bacteria Pseudomonas syringae pv. actinidiae , Ralstonia solanacearum, and Erwinia carotovora by agar and broth dilution methods. Compounds 1 – 6 showed potent antibacterial activity against R. solanacearum with MIC values of 25–50 μg/mL and relatively lower activity against P. syringae pv. actinidiae with MIC values of 50–100 μg/mL, while they were inactive to E. carotovora .

Zopfiellasins A–D, Two Pairs of Epimeric Cytochalasins from Kiwi-Associated Fungus Zopfiella sp. and Their Antibacterial Assessment

“…Compounds 1 – 4 were evaluated for their antibacterial activity against Psa using the previously reported method [ 11 ]. As a result, compounds 1 and 3 exhibited certain inhibitory activity on Psa with MIC values of 25 and 50 μg/mL.…”

“…Currently, the main methods for the treatment of canker include copper preparation pesticides and biological control [7][8][9]. Although some recent chemical fungicides, such as peptides [10], neolignans [11], 1,4-benzoxazin-3-one derivatives [12], and synthetic 1,2,3-triazole-tailored carbazoles [13], have good antibacterial activity against Psa, there are increasing concerns about the harmful impacts of chemical fungicide residues on human health and the environment. Therefore, there is still a lack of safe and effective prevention methods for canker disease.…”

Identification of anti‐TMV active flavonoid glycosides and their mode of action on virus particles from Clematis lasiandra Maxim

“…As part of our project on the discovery of novel antiviral constituents from terrestrial plants, the aerial part of Clematis lasiandra Maxim, collected from Qin Mountains, Shaanxi Province, China was studied. Our previous studies on chemical constituents from the genus Clematis have demonstrated that triterpenoid saponins have antitumor and insecticidal activities, 21,22 and lignanoids are nontoxic constituents that show potent antibacterial activities 23,24 . Herein, we report the isolation and identification of a new flavonoid glycoside and nine known flavonoids from C. lasiandra .…”

“…Our previous studies on chemical constituents from the genus Clematis have demonstrated that triterpenoid saponins have antitumor and insecticidal activities, 21,22 and lignanoids are nontoxic constituents that show potent antibacterial activities. 23,24 Herein, we report the isolation and identification of a new flavonoid glycoside and nine known flavonoids from C. lasiandra. In addition to their antiviral activities including protective, inactivation and curative activities against TMV in Nicotiana glutinosa L., we studied the systemic resistance against TMV induced by flavonoid glycosides in N. glutinosa and N. tabacum L. cv.…”

Anti-Inflammatory Benzofuran Neolignans from the Fruits of Canarium album (Chinese Olive)

“…Additionally, the relative configurations of H-7 and H-8 were established as erythro-configuration on the basis of a small chemical shift difference of H-9a and H-9b (Δδ H9a−H9b = 0.02) as shown in Figure 3. 31,32 An E-configuration for Δ 7 ″ ,8 ′′ was confirmed by the coupling constant between H-7″ and H-8′′ as 15.9 Hz. Consequently, compound 1 was entirely determined as 1-(4-hydroxy-3-methoxyphenyl) −2-[4-[5-((E)-3-hydroxy-1-propen-1-yl)-7-methoxy-2-benzofuranyl]-2-methoxyphenoxy]-1,3-propanediol, and this planar structure was named as canariol A.…”