Trinh Thi Thuy

Counlarins, limonoids and an alkaloid from Clausena excavata

In addition to a known alkaloid, some limonoids and coumarins, the new coumarins excavatins A–M have been isolated from Clausena excavata. Their structures have been assigned by NMR and CD investigations.

Chalcones and ecdysteroids from Vitex leptobotrys

Abstract In addition to some known chalcones and ecdysteroids three new chalcones have been isolated from aerial parts of Vitex leptobotrys , the structures of which have been identified as 2′,4′-dihydroxy-4,6′-dimethoxychalcone, 4′-hydroxy-4,2′,6′-trimethoxychalcone and 4,2′,4′, β -tetrahydroxy-6′-methoxy- α , β -dihydrochalcone, respectively.

Bishordeninyl terpene alkaloids from Zanthoxylum avicennae

Abstract In addition to (−)-culantraramine and (−)-culantraraminol the bishordeninyl terpene alkaloids, (−)-culantraramine N-oxide, (−)-culantraraminol N-oxide and avicennamine, have been isolated from the leaves of Zanthoxylum avicennae. Their structures have been assigned by MS and especially by NMR investigations.

(20R)-O-(3)-α-l-arabinopyranosyl-pregn-5-en-3β,20-diol from Brucea javanica

Abstract The new glycoside, (20R)-O-(3)-α- l -arabinopyranosyl-pregn -5- en -3β,20- diol , was isolated from leaves of Brucea javanica Merr. The structure was determined by 1H and 13C NMR spectroscopy.

Isolation, characterisation and biological evaluation of a phenoxazine, a natural dyestuff isolated from leaves of Peristrophe bivalvis.

Peristrophe bivalvis (L.) Merr. (Acanthaceae) is a wild growing and cultivated plant used for dyeing of foods by the ethnic minorities of Vietnam. The major component of the colour aqueous extract (CAE) of its leaves was identified as peristrophine by spectral analysis, especially the 2D NMR spectra (HSQC, HMBC and NOESY). Considering the widespread utilisation of the decoction of this plant for food dyeing, we evaluated the acute oral toxicity of the CAE. Based on the results in an acute toxicity study in mice, the LD50 value of the CAE was determined as 9100 ± 290 mg kg−1 body weight. Additionally, in vitro cytotoxic assay showed an inhibition of peristrophine against Hepatocellular carcinoma (HepG2, IC503.90 µg mL−1). CAE and peristrophine (1) have also been tested for their ability to affect the cell number of the OCI acute myeloid leukaemia cell line. CAE and peristrophine significantly decreased the OCI cell number at different concentrations and times of treatment.

SUMO proteins: Guardians of immune system

Small ubiquitin-like modifier (SUMO) proteins belong to the ubiquitin-like family and act to change the function of target proteins through post-translational modifications. Through their interactions with innate immune pathways, SUMOs promote an efficient immune response to pathogenic challenge avoiding, at the same time, an excess of immune response that could lead to the development of autoimmune diseases. This report discusses the general functions of SUMO proteins; highlights SUMO involvement in the innate immune response through their role in NF-κB and interferon pathways; the involvement of SUMO proteins in autoimmune diseases; and reviews bacterial, viral, and parasitic interactions with SUMO pathways. In conclusion, we speculate that targeting SUMOs could represent a new therapeutic strategy against infections and autoimmunity.

INVESTIGATING THE ANTI-INFLAMMATORY ACTIVITY OF AN ETHANOLIC EXTRACT FROM ARTOCARPUS TONKINENSIS LEAVES USING A COLLAGEN ANTIBODY-INDUCED ARTHRITIC MOUSE MODEL

This study was contrived for evaluating the in vitro and in vivo anti-inflammatory effects of an aqueous ethanolic leaf extract of the Vietnamese Artocarpustonkinensis A. Chev. exGagnep. usinglipopolysaccharide-stimulated RAW 264.7 macrophages and a collagen antibody-induced arthritic mouse model as well. The obtained results here demonstrate that the 70 % ethanolic leaf extract of A. tonkinensis(AT2), traditionally used in Vietnamese folk medicine for treating arthritic symptoms, has beneficial effects on pro-inflammatory cytokine inhibition and in an experimental arthritic mouse model.LPS-stimulated RAW 264.7 macrophages treated with AT2 showed a significant decrease in the production of IL-6 and TNF at concentrations of 12.5, 25 and 50 μg/mL (P < 0.05), indicating its potential anti-inflammatory properties. The treatment of CAIA mice with AT2 also led to diminish the incidence of arthritis at doses of 200 and 300 mg/kg body weight.

Chemical constituents from the leaves of Pinus dalatensis Ferré

Abstract A phytochemical study of n-hexane and ethyl acetate extracts of Pinus dalatensis Ferré leaves led to the isolation of 11 compounds, including one caryolane sesquiterpenoid (1), five labdane diterpenoids (2, 3, 4, 5, 6), one serratane triterpenoid (7), one diacylated flavonoid glucoside (8), one stilbenoid (9) and two sterols (10, 11). The structural characterisation of the isolated compounds was elucidated by spectroscopic data and comparison with the literature report on the chemical constituents from Pinus dalatensis Ferré. Futhermore, three compounds 1, 4 and 6 were obtained for the first time from the genus Pinus. Besides, compounds (2, 3, 5, 8, 9) were also subjected to cytotoxicity effect on SK-LU-1, MCF-7 and Hep-G2 cell lines, but only compound 9 expressed activities with IC50 values of 141.22, 127.81 and 166.84 μM, respectively.

Anti-proliferative diterpenes from Dacrycarpus imbricatus

Abstract A new diterpene, cassipouryl hexadecanoate (2), in addition to the cassipourol (1) and four terpenes (3–6) were isolated from the twigs and leaves of Dacrycarpus imbricatus (Blume) de Laub. The structures of the two monocyclic diterpenes (1, 2), were elucidated on the basic of 1D and 2D NMR spectroscopic data and compared with the literature. These two monocyclic diterpenes (1, 2) were tested for their anti-proliferative activity on acute myeloid leukemia (OCI-AML) cells. The results showed that 1 had significantly anti-proliferative activity whereas 2 was weakly active.

Cytotoxic Alkaloids from Stephania dielsiana

The genus Stephania belongs to the family Menispermaceae, widely distributed in Africa, India, Southeast Asia, and the northern and eastern parts of Australia. They comprise more than 60 species, in which several Stephania genus were used as folk remedies [1]. Many alkaloids with interesting pharmacological activity were isolated from this genus [2]. Stephania dielsiana Y. C. Wu is a medicinal plant, which has been used in Vietnamese traditional medicine as an analgesic and sedative and for the treatment of neuralgia, stomachache, and arthritis. There are some reports on the chemical constituents of the tubers of this species [3–5]. Some isolated compounds showed antimicrobial, hypotensive, and anticarcinogenic activities [6, 7]. In this study, seven alkaloids, tetrahydropalmatine (1), stephanine (2), crebanine (3), O-methylbulbocapnine (4), oxostephanine (5), palmatine (6), and thailandine (7), were isolated from the leaves of this plant. The structures of these alkaloids were elucidated by spectroscopic methods, including MS, PMR, 13C NMR, HSQC, and HMBC and compared with the reported references. Among them, compounds 4, 6, and 7 were isolated for the first time from this plant. Some alkaloids from Stephania were investigated for their cytotoxic activities against some kinds of mammalian cancer cell lines such as KB, HepG2, MRC-5, MCFGLC4, GLC4/Adr, K562, and K562/Adr [2, 8–10]. Herein, the isolated alkaloids 1–7 were tested for their cytotoxic activities against human breast cancer cell line (BT474) and human colon cancer cell line (HCT116). Docetaxel was used as positive control [11]. Testing was carried out in triplicate for each compound and concentration. Then the results were analyzed and processed statistically. The IC50 values are listed in Table 1. All tested compounds exhibited antiproliferative activities against two cancer cells tested. Compounds 2 and 3 demonstrated potent cytotoxicity against BT474 cell with IC50 of 1.55 and 1.58 g/mL, respectively. Compound 7 showed strong cytotoxicity against both cell lines (IC50 = 1.89 and 2.76 g/mL, respectively).