Shi-Jin Qu

Tryptamine derivatives as novel non-nucleosidic inhibitors against hepatitis B virus.

A series of tryptamine derivatives were synthesized and evaluated for their anti-hepatitis B virus (HBV) activity and cytotoxicity in the HepG2.2.15 cell line. The preliminary SAR was discussed. Compounds 2e and 4a showed potent antiviral activity (IC(50)=0.4 and <1 μM, respectively) and low cytotoxicity (CC(50)=40.6 and >25 μM, respectively).

Lamiolactone, a new iridoid lactone from Lamiophlomis rotata.

Lamiolactone (1), a new iridoid lactone, together with five known iridoids, were isolated from the 95% EtOH extract of the roots of Lamiophlomis rotata. The structure of 1 was elucidated to be methyl antirrhinolide-4-carboxylate on the basis of spectroscopic analysis.

Two new N-oxide Lycopodium alkaloids from Huperzia serrata

Two new Lycopodium alkaloids, N-oxidehuperzine E (1) and N-oxidehuperzine F (2), along with two known alkaloids, huperzines E (3) and F (4), were isolated from Huperzia serrata (Thunb.) Trev. Their structures were elucidated by spectroscopic and chemical transformations.

Arylnaphthalene lignan glycosides and other constituents from Phyllanthus reticulatus

Two new arylnaphthalene lignan glycosides, named reticulatusides A (1) and B (2), together with eight known compounds were isolated from the 95% EtOH extract of the whole plant of Phyllanthus reticulatus. The structures of the new compounds were elucidated by spectroscopic methods.

Lycopodium alkaloids from Huperzia serrata.

A new lycopodane-type Lycopodium alkaloid, 6α-hydroxy-5,15-oxide-lycopodane (1), and seven known alkaloids were isolated from the whole plants of Huperzia serrata. Their structures were elucidated by means of spectroscopic methods. 12-Deoxyhuperzine O (2) was reported as a naturally occurring alkaloid for the first time, and showed an antagonist effect on the N-methyl-d-aspartate receptor with an IC50 value of 0.92 μM.

Triterpenoids from the barks of Terminalia chebula

Two new triterpenoids, termichebuloside A (1), an unusual dimeric triterpenoid saponin, and termichebulolide (2), an oleanolic acid-type lactone, along with 11 known triterpenoids, were isolated from MeOH extract of the barks of Terminalia chebula. The structures of 1 and 2 were elucidated to be arjunglucoside I-(3-O-19′,23-O-19′)-18,19-seco-19-hydroxyarjunglucoside I (1) and 2α,3β,23-trihydroxyolean-11,13(18)-dien-28,19β-olide (2), respectively, on the basis of spectroscopic evidences and biogenetic consideration.

Minor dammarane saponins from the hongshen extract of Shenmai injection.

A new dammarane-type triterpenoid saponin, (20R)-ginsenoside ST2 (1), along with five known saponins was isolated from the hongshen extract of Shenmai injection. The structure of 1 was elucidated to be (20R)-dammar-23(E)-ene-3β,6α,12β,20,25-pentol 6-O-β-d-glucopyranoside by means of spectroscopic methods.

Two new isomeric alpha-tetralones from Pyrola calliantha.

Callianthones A ( 1) and B ( 2), a pair of new isomeric alpha-tetralones, together with a known alpha-tetralone ( 3) and four known flavonoids ( 4 - 7) were isolated from the 50 % EtOH extract of Pyrola calliantha. The structures and absolute configurations of the two new isomers were established to be (2 S,4 R) - and (2 S,4 S)-2,4-dihydroxy-2,7-dimethyl-3,4-dihydronaphthalen-1(2 H)-one ( 1 and 2, respectively) on the basis of spectral analysis, including 2 D NMR, model studies, and CD spectra.

Limonoids from the fruits of Swietenia macrophylla with inhibitory activity against H 2 O 2 -induced apoptosis in HUVECs

The fruits of Swietenia macrophylla (skyfruits) are commercially used as healthcare products to improve blood circulation. An investigation of active ingredients of skyfruits led to the isolation of four new limonoids, swietemacrolides A-D (1-4), together with ten known limonoids (5-14) and one proto-limonoid (15). Their structures were elucidated on the basis of MS and NMR data analysis. Swietemacrolide C (3) at the concentration of 10 μM showed significant protective effect on H2O2-induced apoptosis in human umbilical vascular endothelial cells (HUVECs), while swieteliacate D (5) displayed moderate anti-apoptotic activity.

Pyramidatine (Z88) Sensitizes Vincristine-Resistant Human Oral Cancer (KB/VCR) Cells to Chemotherapeutic Agents by Inhibition of P-glycoprotein

BACKGROUND Multi-drug resistance (MDR) remains a major impediment in cancer therapy. A major goal for scientists is to discover more effective compounds that are able to circumvent MDR and simultaneously have minimal adverse side effects. OBJECTIVE In the present study, we aim to determine the anti-MDR effects of pyramidatine (Z88), a cinnamic acid-derived bisamide compound isolated from the leaves of Aglaia perviridis, on KB/VCR (vincristineresistant human oral cancer cells) and MCF-7/ADR (adriamycin-resistant human breast adenocarcinoma) cells. METHODS Cell viability and average resistant fold (RF) of Z88 were examined by Cell Counting Kit-8 (CCK-8) assay. Flow cytometry, western blot, RT-PCR, Rhodamine 123 accumulation assay and P-glycoprotein (P-gp) ATPase assay were used to demonstrate the anti-MDR activity and mechanism of Z88. RESULTS The average RF of Z88 is 0.09 and 0.51 in KB/VCR and MCF-7/ADR cells. A CCK-8 assay showed that Z88 could enhance the cytotoxicity of VCR toward KB/VCR cells. A FACS analysis revealed that Z88 could enhance the VCR-induced apoptosis as well as G2/M arrest in a dose-dependent manner in KB/VCR cells. Western blot results showed that the expression levels of PARP, Bax, and cyclin B1 all increased after treatment with 0.2 µmol/L (µM) of VCR combined with 10 µM of Z88 for 24 h in KB/VCR cells. Z88 also could enhance the accumulation of rhodamine 123. Further studies showed that Z88 could inhibit the verapamil stimulated Pgp ATPase activity. Additionally, qPCR detection and western blot assays revealed that Z88 could decrease the expression of P-gp at both RNA and protein level. CONCLUSION Z88 exerted potent anti-MDR activity in vitro and its mechanisms are associated with dualinhibition of the function and expression of P-gp. These findings encourage efforts to develop more effective reversal agents to circumvent MDR based on Z88.