Three New Pregnanes Isolated from the Cynanchum auriculatum

A new quinoline alkaloid, 5‐hydroxy‐6‐methoxy‐N‐methyl‐2‐phenylquinoline‐4‐one (1), and seventeen known quinoline alkaloids (2–18) were isolated from the roots of Orixa japonica. The structure of 1 was determined by analysis of spectroscopic data. Among them, compounds 2, 3, and 13 were isolated from this plant for the first time. All isolates were screened for the anti‐pathogenic fungi activities, including Rhizoctonia solani, Magnaporthe oryzae, and Phomopsis sp. The results showed that five compounds (4, 8, 10, 11, and 12) exhibited significant anti‐pathogenic fungi effects at 50.0 μg/mL. In special, compound 10 exhibited the best antifungal activities toward R. solani and M. oryzae with the IC50 values of 37.86 and 44.72 μM, respectively, better than that of the positive control, hymexazol (IC50 121.21 and 1518.18 μM, respectively). Moreover, eleven new quinoline alkaloids derivatives (12a–12k) were designed and synthesized to investigate the structure−activity relationships (SARs). The SARs analysis indicated that the furo[2,3‐b]quinoline skeleton and the methoxy at C‐7 (compounds 8, 11, and 12) played a key role for improving the antifungal activities.

Section: Resultsmentioning

confidence: 99%

Section: In Vvitro Antifungal Activity Assaymentioning

confidence: 99%

Quinoline Alkaloids from the Roots of Orixa japonica with the Anti‐Pathogenic Fungi Activities

Huang

Jian

Fan

et al. 2023

“…The inoculated PDA plates were incubated at 28±1 °C for 4–6 days. The EC50 was determined for compounds at five different concentrations [26–28] . Based on the test of in vitro antifungal activity, compound C17 against Phomopsis sp .…”

Section: Methodsmentioning

confidence: 99%

“…The EC50 was determined for compounds at five different concentrations. [26][27][28] Based on the test of in vitro antifungal activity, compound C17 against Phomopsis sp. was further tested in vivo on kiwifruit.…”

Section: Fungimentioning

confidence: 99%

Synthesis and Antifungal Activity of 2‐(2‐Benzoxazolyl)‐1‐arylethanone and 2‐(2‐Benzoxazolyl)‐1‐alkylethanone Derivatives

Che,

Jin,

Sun

et al. 2023

Self Cite

To discover more effective antifungal candidates, 33 benzoxazole derivatives, were designed, synthesized, and evaluated for their antifungal activity against seven phytopathogenic fungi by the mycelium growth rate method. Among 33 benzoxazole derivatives had thirteen derivatives no reported, and new derivatives C17 exhibited good inhibitory activity against Phomopsis sp. with EC50 values of 3.26 μM. Structure–activity relationship (SAR) of these derivatives analysis indicated that the substituent played a key role in antifungal activity in ortho‐, meta‐ and para‐ substituted acetophenones. The preliminary mechanistic exploration demonstrated that C17 might exert its antifungal activity by targeting the mycelia cell membrane, which was verified by the observed changes in mycelial morphology, the formation of extracellular polysaccharides, cellular contents, cell membrane permeability and integrity, among other effects. Furthermore, C17 had potent curative effect against Phomopsis sp. in vivo, which indicated that C17 may be as a novelty potent antifungal agent.

“…[1,2] C 21 -steroidal glycosides, as typical constituents of C. otophyllum, demonstrate a variety of pharmacological activities, including antitumor, antivirus, immunosuppressive, antiaging, and antidepressant properties. [3][4][5][6][7] Recently, much effort had been made to research the chemical composition of the acid hydrolysate of Cynanchum plants to obtain novel and potent biological active C 21 -steroidal sapogenins, [8][9][10][11][12] especially anticancer activity. [13 -16] Our previous phytochemical investigation resulted in the isolation of nine new C 21 -steroidal sapogenins (cynotogenins AÀ I) and several C 21 -steroidal sapogenins with significant anticancer activity from the acid hydrolysate of C. otophyllum, and the structure-activity relationships (SARs) was discussed.…”

Section: Introductionmentioning

confidence: 99%

Five New C₂₁‐Steroidal Sapogenins from the Acid Hydrolysate of Cynanchum otophyllum Roots

Liang

et al. 2023

Five new C 21 -steroidal sapogenins (1 -5) named cynotogenins JÀ N, were isolated from the acid hydrolysate of Cynanchum otophyllum roots. Their structures were established by extensive spectroscopic analysis (UV, IR, HR-ESI-MS, and NMR). Most notably, compounds 1-3 harboring a rare 5β,6β-epoxy group in the C 21 -steroidal skeleton of Cynanchum plants. All compounds were evaluated for their cytotoxicities against multiple cancer cell lines, in which compounds 5 showed weak cytotoxicity against HepG2 cancer cells with IC 50 values of 44.90 μM.