Nwet Nwet Win

Novel anticancer agents, kayeassamins A and B from the flower of Kayea assamica of Myanmar.

The CHCl(3)-soluble fraction of 70% EtOH extract of the flower of Kayea assamica completely killed human pancreatic PANC-1 cancer cells preferentially under nutrient-deprived conditions at 1 microg/mL. Bioassay-guided fractionation and isolation afforded two novel compounds, kayeassamins A (1) and B (2). Their structures were elucidated using extensive spectroscopic methods and the modified Mosher method. Each compound showed 100% preferential cytotoxicity (PC(100)) against PANC-1 cells under nutrient-deprived conditions at 1 microM. Furthermore, both compounds inhibited the migration of PANC-1 cells in the wound closure assay.

Kaempulchraols A–H, Diterpenoids from the Rhizomes of Kaempferia pulchra Collected in Myanmar

Eight new diterpenoids, kaempulchraols A-H (1-8), along with five known analogues were isolated from the CHCl3-soluble extract of rhizomes of Kaempferia pulchra of Myanmar. The structures of these compounds were elucidated using extensive spectroscopic techniques including X-ray diffraction analysis. All the isolates were tested for their antiproliferative activity against a panel of five human cancer cell lines (A549, human lung cancer; HeLa, human cervix cancer; PANC-1 and PSN-1, human pancreatic cancer; MDA-MB-231, human breast cancer) and TIG-3, normal human primary fibroblast cells. Kaempulchraol F (6) exhibited weak activity against the human pancreatic PSN-1 cell line with an IC50 value of 12.3 μM.

Isopimarane diterpenoids from Kaempferia pulchra rhizomes collected in Myanmar and their Vpr inhibitory activity

Viral protein R (Vpr), an accessory gene of HIV-1, plays important roles in viral pathogenesis. Screening of Myanmar medicinal plants that are popular as primary treatments for HIV/AIDS and for HIV-related problems revealed the potent anti-Vpr activity of the CHCl3-soluble extract of Kaempferia pulchra rhizomes, in comparison with that of the positive control, damnacanthal. Fractionation of the active CHCl3-soluble extract led to the identification of 30 isopimarane diterpenoids, including kaempulchraols A-W (1-23). All isolates were assayed for anti-Vpr activity against TREx-HeLa-Vpr cells, in which Vpr expression is tightly regulated by tetracycline. Kaempulchraols B (2), D (4), G (7), Q (17), T (20), U (21), and W (23) exhibited potent anti-Vpr activity, at concentrations ranging from 1.56 to 6.25μM. The structure-activity relationships of the active kaempulchraols suggested that the presence of a hydroxy group at C-14 in an isopimara-8(9),15-diene skeleton and the presence of an acetoxy group at C-1 or C-7 in an isopimara-8(14),15-diene skeleton are the critical factors for the inhibitory effects against TREx-HeLa-Vpr cells.

Kaempulchraols P-T, Diterpenoids from Kaempferia pulchra Rhizomes Collected in Myanmar.

The isolation of the oily fraction obtained from the CHCl3-soluble extract of the rhizomes of Kaempferia pulchra afforded five new isopimarane diterpenoids, kaempulchraols P-T (1-5), along with two known analogues. The structures were elucidated using spectroscopic techniques, including 2D NMR spectroscopy.

New sesquiterpene lactones, vernonilides A and B, from the seeds of Vernonia anthelmintica in Uyghur and their antiproliferative activities.

A new guaianolide sesquiterpene lactone, vernonilide A (1), and a new elemanolide sesquiterpene lactone, vernonilide B (2), were isolated from the seeds of Vernonia anthelmintica, together with three known elemanolide sesquiterpene lactones (3-5). The structures of the isolated compounds were elucidated on the basis of physicochemical evidences. Compounds 1, 3, and 4 showed strong antiproliferative activities against three human cancer cell lines (A549, HeLa, and MDA-MB-231), with IC50 values ranging from 0.10 to 1.00μM. In addition, 5 exhibited significant antiproliferative activities against HeLa and MDA-MB-231 cells, with IC50 values ranging from 1.90 to 2.20μM. The antiproliferative activities of the acetyl derivatives 6 and 7 prepared from 4 and 3, respectively, against the three cell lines were 4-10-fold weaker than the original activities.

Picrajavanicins A–G, Quassinoids from Picrasma javanica Collected in Myanmar

Seven new tetracyclic quassinoids, picrajavanicins A-G (1-7), along with three known analogues, were isolated from a CHCl3-soluble extract of the bark of Picrasma javanica collected in Myanmar. The structures of these compounds were elucidated using spectroscopic techniques, including 1D and 2D NMR. The absolute configuration at C-2 of 2 was determined to be S by the modified Mosher method. All the isolates were tested for their antiproliferative activities against a small panel of five human cancer cell lines. However, none of the isolated compounds exhibited inhibitory activity against any of the cancer cells used (IC50 values >10 μM).

Quassinoids: Viral protein R inhibitors from Picrasma javanica bark collected in Myanmar for HIV infection

Viral protein R (Vpr) is an accessory protein that plays important roles in the viral pathogenesis of Human Immunodeficiency Virus-1 (HIV-1). An assay for anti-Vpr activity, using TREx-HeLa-Vpr cells, is a promising strategy to discover Vpr inhibitors. The anti-Vpr assay revealed that the CHCl3-soluble extract of Picrasma javanica bark possesses potent anti-Vpr activity. Furthermore, studies of quassinoids (1-15) previously isolated from the extract demonstrated that all of the tested quassinoids exhibit anti-Vpr activity. Among the tested compounds, javanicin I (15) exhibited the most potent anti-Vpr activity ((***)p <0.001) in comparing with that of the positive control, damnacanthal. The structure-activity relationships of the active quassinoids suggested that the presence of a methyl group at C-13 in the 2,12,14-triene-1,11,16-trione-2,12-dimethoxy-18-norpicrasane quassinoids is the important factor for the potent inhibitory effect in TREx-HeLa-Vpr cells.

New merosesquiterpenes from a Vietnamese marine sponge of Spongia sp. and their biological activities

The investigation of the Vietnamese marine sponge Spongia sp. led to the isolation of three new sesquiterpene phenols, langconols A-C (1-3), and one new sesquiterpene hydroxyquinone, langcoquinone C (4), together with two known meroterpenoids (5 and 6). Their structures were determined on the basis of spectroscopic analyses and comparisons with published data. Furthermore, the antibacterial assays of the isolates 1-6 suggested that 4 and 6 had significant antibacterial activities against Bacillus subtilis and Staphylococcus aureus, with MICs ranging from 6.25 to 25.0µM, while 1 and 3 possessed significant antibacterial activities against B. subtilis with MICs of 12.5 and 25.0µM, respectively. In contrast, cytotoxic assays of the isolated compounds 1-6, as well as compounds 7-15 previously isolated from this sponge, indicated that 1 and the previously reported anti-B. subtilis and anti-S. aureus sesquiterpene phenol 9 lacked cytotoxic activities against three human cancer cell lines (A549, lung cancer; MCF7, breast cancer; HeLa, cervix cancer) and a human normal cell line (WI-38 fibroblast).

Anti-influenza virus activity of extracts from the stems of Jatropha multifida Linn. collected in Myanmar

BackgroundTo contribute to the development of novel anti-influenza drugs, we investigated the anti-influenza activity of crude extracts from 118 medicinal plants collected in Myanmar. We discovered that extract from the stems of Jatropha multifida Linn. showed anti-influenza activity. J. multifida has been used in traditional medicine for the treatment of various diseases, and the stem has been reported to possess antimicrobial, antimalarial, and antitumor activities. However, the anti-influenza activity of this extract has not yet been investigated.MethodsWe prepared water (H2O), ethyl acetate (EtOAc), n-hexane (Hex), and chloroform (CHCl3) extracts from the stems of J. multifida collected in Myanmar, and examined the survival of Madin-Darby canine kidney (MDCK) cells infected with the influenza A (H1N1) virus, and the inhibitory effects of these crude extracts on influenza A viral infection and growth in MDCK cells.ResultsThe H2O extracts from the stems of J. multifida promoted the survival of MDCK cells infected with the influenza A H1N1 virus. The EtOAc and CHCl3 extracts resulted in similar, but weaker, effects. The H2O, EtOAc, and CHCl3 extracts from the stems of J. multifida inhibited influenza A virus H1N1 infection; the H2O extract possessed the strongest inhibitory effect on influenza infection in MDCK cells. The EtOAc, Hex, and CHCl3 extracts all inhibited the growth of influenza A H1N1 virus, and the CHCl3 extract demonstrated the strongest activity in MDCK cells.ConclusionThe H2O or CHCl3 extracts from the stems of J. multifida collected in Myanmar demonstrated the strongest inhibition of influenza A H1N1 viral infection or growth in MDCK cells, respectively. These results indicated that the stems of J. multifida could be regarded as an anti-influenza herbal medicine as well as a potential crude drug source for the development of anti-influenza compounds.

A new polyoxygenated cyclohexene and a new megastigmane glycoside from Uvaria grandiflora.

A new polyoxygenated cyclohexene, (-)-3-O-debenzoylzeylenone (1), and a new megastigmane glycoside, grandionoside A (2), were isolated from the aerial parts of Uvaria grandiflora collected in Vietnam, together with ten known compounds including polyoxygenated cyclohexenes (3-6), a triterpenoid (7), an alkaloid (8), a long chain alcohol (9), hexenyl glycopyranoside (10), and saponins (11-12). Their chemical structures were elucidated by a combination of extensive NMR spectroscopy with X-ray crystallographic analysis for 1, and chemical conversion for 2. Compound 1 exhibited significant cytotoxicity against the LU-1 and SK-Mel-2 cell lines with IC50 values of 4.68 and 3.63 μM, respectively. Remarkably, the cytotoxicity of 12 against the LU-1, KB, Hep-G2, MKN-7, and SW-480 cell lines was comparable to that of ellipticine, the positive control, with IC50 values ranging from 1.24 to 1.60 μM.