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Objective: To study the low polar constituents from Annona squamosa fruit pericarp., Methods: The fruit pericarp was percolated with 95% EtOH at room temperature. The extract was subjected to Silica gel chromatography and eluted with gradually more polar and EtOAc-MeOH mixtures. The part eluted range Pet-EtOAc from 5:1 to 1:1 was subjected to repeated column chromatography. The constituents were identified by physicochemical property and NMR data., Results: Eight constituents were isolated and identified as tricosane(1), β-sitosterol(2), succinic acid (3), annosquamosin D(4), 4α-hydroxy-19-nor-(E)-kauran-17-oic acid(5), (E)-16β, 17-dihydroxy-kauran-19-oic acid(6), (E)-16α, 17-dihydroxy-kauran-19-oic acid(7), and 16β-hydroxy-17-acetoxy-(E)-kauran-19-oic acid(8)., Conclusion: All constituents are firstly isolated from Annona squamosa fruit pericarp except compound 6.

Objective: To investigate the constituents of the Annona squamosa and evaluate their anti-tumor activity., Method: The compounds were isolated and purified by various column chromatography. Their structures were elucidated by spectral data analysis. Their anti-tumor activity was assayed by SRB method., Result: Eleven compounds were obtained from the 95% EtOH extract. The structures were determined as: annosquamosin C(1),15, 16-epoxy-17-hydroxy-ent-kau-ran-19-oic acid (2),16,17-dihydroxy-ent-kau-ran-19-oic acid(3), annosquamosin A(4), ent-kaur-16-en-19-oic acid (5), 19-nor-ent-kauran4-ol-17-oic acid (6),16-hydroxy ent-kau ran-19-oic acid (7), ent-15beta-hydroxy-kaur-16-en-19-oic acid (8), annosquamosin B (9), ent-16beta, 17-dihydroxykauran-19-al (10), 16, 17-dihydroxy-ent-kauran-19-oic acid me thyl ester (11). Compounds 1,2,3,5,9 showed different inhibitory activities against 95-D lung cancer cells,the effect of compound 5 was strongest with the IC50 value 7.78 micromol x L(-1); Compounds 2, 5, 9 showed inhibitory activities against A2780 ovarian cancer cells, the effects of compounds 2 and 9 were strong with the IC50 values being 0.89, 3.10 micromol x L(-1), respectively., Conclusion: Compound 2 was firstly isolated from this family, while compound 8 and 10 were first found from this genus and the title species, respectively. The in vitro anti-tumor test showed compound 5 significantly inhibited 95-D lung cancer cells and compounds 2 and 9 exhibited remarkbale activity against A2780 ovarian cancer cells.

Many major neurodegenerative diseases are associated with proteins misfolding and aggregation, which are also called "neurodegenerative conformational disease". The interaction of gene mutation and environmental factors are probably primary events resulting in oligomer and aggregate formations of proteins. Moreover, the dysfunctions of protein control systems, i.e. the ubiquitin-proteasome system and autophagy-lysosomal system, also contribute to the neurodegenerative process. The present review mainly summarizes protein misfolding and aggregation in the development of neurodegenerative conformational disease and the underling mechanisms, as well as upregulation of heatshock proteins as a promising treatment method for this kind of disease.

Aim: To study the antitumor active constituents of the seeds from Annona squamosa L. (Annonaceae)., Methods: Various chromatographic techniques were used to isolate and purify the constituents. Their physico-chemical properties and spectral data were determined to elucidate the structures., Results: Eleven compounds were isolated and identified as annonaceous acetogenins: squamocenin (1), annotemoyin-2 (2), reticulatain-2 (3), squamocin-I (4), squamocin-B (5), squamocin (6), motrilin (7), squamostatin-D (8), squamostatin-E (9), cherimolin-1 (10), cherimolin-2 (11) from the ethyl alcohol extract of A. squamosa L., Conclusion: Squamocenin (1) is a new acetogenin. Annotemoyin-2 (2) and reticulatain-2 (3) were isolated from this plant for the first time.

Aim: To study the inhibition of oxygen consumption by annonaceous acetogenins (ACG) and their structure-activity relationship (SAR)., Methods: The inhibition of oxygen consumption in chicken liver cell respiration by different structural ACG was studied by using oxygen electrode technique., Results: Six ACG showed potent inhibitory effects like rotenone which was a classical inhibitor of mitochondrial complex I, and was more potent than complex IV inhibitor KCN. The IC50 values of six ACG for inhibiting oxygen consumption suggested that bistetrahydrofuran (THF) ACG was 7-11 times more active than non-THF ACG, and A1-type ACG was more potent than A2-type ACG., Conclusion: The terminal gamma-lactone was crucial for the inhibition of oxygen consumption. The distance between THF and gamma-lactone, the hydroxyl groups in the alkyl chain, were the important factors of SAR, but the 4-OH group possibly played some negative role in the exhibit of potent activity.

Aim: To develop a method for analysis of antitumor annonaceous acetogenins in Annonaceae plants by HPLC., Methods: Squamostatin-B (1), squamocin (2) and annonin-VI (3) were used as standard substances. Chromatography column was a Rp-18; the mobile phase was methanol-water (90:10); the flow rate was 1.0 mL.min-1 and the detecting wavelength was 220 nm., Results: A linear range was obtained from 2.3 to 13.8 micrograms with a good correlation. The recoveries of (1), (2) and (3) were 100.3%, 100.3% and 100.0%, respectively., Conclusion: This method was developed for the analysis of acetogenins by HPLC for the first time. The method is rapid, accurate and suitable for the analysis of the antitumor acetogenins in Annonaceae plants.

Aim: To investigate the mechanism of apoptosis of HL60 cells induced by the annonaceous acetogenin, squamocin., Methods: Induction of apoptosis was determined through Hoechst33258 dye staining and DNA agarose gel electrophoresis. Expression of the proteins was detected using Western blot analysis. Caspase-3 activity was detected using caspase-3 kit., Results: Treatment of HL-60 cells with squamocin resulted in extensive nuclear condensation, DNA fragmentation, cleavage of the death substrate poly(ADP-ribose) polymerase (PARP) and induction of caspase-3 activity. Pretreatment of HL-60 cells with caspase-3 specific inhibitor DEVD-CHO prevented squamocin-induced DNA fragmentation, PARP cleavage and cell death. Stress-activated protein kinase (SAPK/JNK) was activated after treatment with squamocin in HL-60 cells., Conclusion: These results suggest that apoptosis of HL-60 cells induced by squamocin require caspase-3 activation, and could be related to SAPK activation.