Indole Alkaloids Inhibiting Neural Stem Cell from Uncaria rhynchophylla

Uncaria rhynchophylla is commonly recognized as a traditional treatment for dizziness,cerebrovascular diseases,and nervous disorders in China.Previously,the neuro-protective activities of the alkaloids from U.rhynchophylla were intensively reported.In current work,three new indole alkaloids(1–3),identified as geissoschizic acid(1),geissoschizic acid N4-oxide(2),and 3b-sitsirikine N4-oxide(3),as well as 26 known analogues were isolated from U.rhynchophylla.However,in the neural stem cells(NSCs)proliferation assay for all isolated compounds,geissoschizic acid(1),geissoschizic acid N4-oxide(2),isocorynoxeine(6),isorhynchophylline(7),(4S)-akuammigine N-oxide(8),and(4S)-rhynchophylline N-oxide(10)showed unexpected inhibitory activities at 10 μM.Unlike previous neuro-protective reports,as a warning or caution,our finding showcased a clue for possible NSCs toxicity and the neural lesions risk of U.rhynchophylla,while the structure–activity relationships of the isolated compounds were discussed also.

Three new physalins from Physalis alkekengi var. franchetii

Three new physalin steroids,physalin Ⅲ(1),physalin IV(2),3-O-methylphysalin X(3),together with five known physalins(4-8)were isolated from the 80%EtOH extract of calyces of Physalis alkekengi var.franchetii.The structures of the new compounds were revealed through 1D and 2D NMR and mass spectroscopic studies.

Antifungalmycin,an antifungal macrolide from Streptomyces padanus 702

Two polyene macrolide antibiotics:antifungalmycin(1)and fungichromin(2)were isolated from the culture mycelia of Streptomyces padanus 702 via bioactivity-guided fractionation using various chromatographic procedures.Their structures were elucidated on the basis of spectral analysis,and 1 is a new polyene macrolide.Compounds 1 and 2 showed significant inhibition against Gibberella zeae with EC_(50)values of 26.71 and 2.21μg/mL,Fusicoccum sp.(plantain head blight)with EC_(50)values of 23.4 and 3.17μg/mL,Mucor ssp.8894 with EC_(50)values of 28.80 and 2.11μg/mL,Ustilaginoidea virens with EC_(50)values of 26.72 and 0.21μg/mL,respectively.This shows that the microbial secondary metabolites 1 and 2 have the potential to be developed as agricultural fungicides for use against G.zeae,Fusicoccum sp.,Mucor ssp.8894,and U.virens.

New monoterpene phenyl ethers from Illicium micranthum

Seven new monoterpene phenyl ethers,namely micranthumnins A-G(1-7),were isolated from the stem bark of Illicium micranthum(Illiciaceae).Their structures were elucidated by comprehensive spectroscopic analyses including MS,IR,1D and 2D NMR.All compounds were evaluated for their anti-AChE activities.

Three New Pyridine Alkaloids from Vinca major Cultivated in Pakistan

Three new pyridine type alkaloids,(-)-vinmajpyridines A–C(1–3),along with two known alkaloids,have been isolated from the aerial parts of Vinca major cultivated in Pakistan.Their structures have been elucidated by means of NMR and HRESIMS spectroscopic data.The new alkaloids were evaluated for their cytotoxicity against glioma initiating cell lines(GITC-3#and GITC-18#),glioblastoma cell lines(U-87MG and T98G),and lung cancer cell line A-549,but none of them was active at 20 lg/mL concentration.

Sesquilignans and sesquiterpenoid from the stem barks of Illicium simonsii and their anti-AChE activity

Three new sesquilignans,1-3,a new sesquiterpenoid,4,and three known compounds were isolated from the stem barks of Illicium simonsii.The structures of new compounds(1-4)were elucidated by spectroscopic methods.A biosynthetic pathway was proposed for simonsienols A-C(1-3).Anti-AChE activity and anti-BuChE activity were evaluated for all compounds except forα-cadinol ethyl ether(4).As a result,isodunnianol(7)exhibited anti-AChE activity with an IC50 value of 13.0μM.