Flavanols and Flavanes from Crinum asiaticum and Their Effects on LPS Signaling Pathway Through the Inhibition of NF-κB Activation.

Three new flavanols, (2R,3S)-7-methoxy-flavan-3-ol (1: ), (2R,3S)-7-hydroxy-flavan-3-ol (2: ), and (2R,3S)-2'-hydroxy-7-methoxy-flavan-3-ol (3: ), together with two known flavans (4: and 5: ), were isolated from the chloroform extract of Crinum asiaticum. Their structures were elucidated by various spectroscopic methods, including 1D and 2D NMR, HR-ESI-MS, and CD data. The isolated compounds 1: and 3: -5: showed inhibitory activity toward LPS-induced nitric oxide (NO) production. Further investigation of the NF-κB pathway mechanisms indicated that 1: and 3: -5: inhibited the LPS-induced IL-6 production and p65 subunit phosphorylation of NF-κB in RAW264.7 cells, with an effective dose of 10 µM.

Flavonoids from Woodfordia fruticosa as potential SmltD inhibitors in the alternative biosynthetic pathway of peptidoglycan.

SmltD is an ATP-dependent ligase that catalyzes the condensation of UDP-MurNAc-l-Ala and l-Glu to form UDP-MurNAc-l-Ala-l-Glu, in the newly discovered peptidoglycan biosynthesis pathway of a Gram-negative multiple-drug-resistant pathogen, Stenotrophomonas maltophilia. Phytochemical investigation of the 70% ethanol extract from Woodfordia fruticosa flowers collected in Myanmar led to the identification of anti-SmltD active flavonoids, kaempferol 3-O-(6''-galloyl)-ß-d-glucopyranoside (1), astragalin (2), and juglalin (3). Among them, 1 showed the most potent SmltD inhibitory activity. An enzyme steady-state kinetic study revealed that 1 exerted competitive inhibition with respect to ATP. The results of this study provided an attractive foundation for the further development of novel inhibitors of SmltD.

Identification of Ophiocordyceps gracilioides by Its Anti-tumor Effects through Targeting the NFκB-STAT3-IL-6 Inflammatory Pathway.

Although more than 400 species of Cordyceps s.l. have been identified, most have not been well explored regarding their potential for medicinal use. In this study, the profiles of constituents of ten different species of Ophiocordyceps, which is an unexplored species of Cordyceps, were analyzed and their anti-tumor effects were further examined. Although all Ophiocordyceps samples exhibited similar peak patterns, Ophiocordyceps gracilioides (O. grac) had a distinct constituent profile from the other samples. Furthermore, O. grac was the most active in suppressing the transcriptional activities of both nuclear factor-kappa B (NF-κB) and signal transducer and activator of transcription (STAT)3, and the production of interleukin (IL)-6 from breast cancer cells. This study demonstrated that O. grac is a relatively unexplored Cordyceps s.l. that may have medicinal potential to inhibit the NFκB-STAT3-IL-6 inflammatory pathway in cancer.

Pyrrolactams from Marine Sponge Stylissa massa Collected from Myanmar and Their Anti-Vpr Activities.

A new brominated pyrrolactam stylissaol A (1) together with four known analogues, 2-bromoaldisine, aldisine, spongiacidin D, and Z-hymenialdisine, were isolated from the EtOAc extract of marine sponge Stylissa massa collected in Myanmar. The absolute configuration at C-10 of 1 was determined as R by the electronic circular dichroism (ECD) data. Among the isolated compounds, 2-bromoaldisine showed anti-Viral Protein R (Vpr) activity against TREx-HeLa-Vpr cells with an effective dose of 10 µM and its potency was comparable to that of positive control damnacanthal.

Shanpanootols G and H, Diterpenoids from the Rhizomes of Kaempferia pulchra Collected in Myanmar and Their Vpr Inhibitory Activities.

Two new trihydroxy derivative of Δ8(14),15-isopimarane diterpenoids, shanpanootols G (1) and H (2), along with three known analogues were isolated from the ethyl acetate-soluble extract of Kaempferia pulchra rhizomes collected in Shan State of Myanmar. The structures of these compounds including their absolute configurations were elucidated by the combination of one dimensional (1D) and 2D-NMR spectroscopic methods, high resolution mass spectrometric technique, and the experimental and the calculated electronic circular dichroism (ECD) data. The isopimarane diterpenoids (1-5) were tested for their Viral protein R (Vpr) inhibitory activities against TREx-HeLa-Vpr cells. Shanpanootol H (2) and (1R,2S,5S,9R,10S,13R)-1,2-dihydroxypimara-8(14),15-dien-7-one (4) exhibited anti-Vpr activities at the 5 µM treated dose.

Dinorcassane Diterpenoid from Boesenbergia rotunda Rhizomes Collected in Lower Myanmar.

A new dinorcassane diterpenoid, seikphoochinal A (1), and four known compounds, pinostrobin (2), 4',7-dimethylkaempferol (3), and galanals A (4) and B (5), were isolated from the chloroform-soluble crude extract of wild type Boesenbergia rotunda rhizomes collected in Lower Myanmar. The chemical structures of these compounds were identified, using a combination of spectroscopic methods. The presence of the diterpenoids 1, 4, and 5 demonstrated the structural diversity of wild type B. rotunda. Among the isolates, compounds 4 and 5 exhibited significant antiproliferative activities against a small panel of human cancer cell lines, including lung (LK-2, A549), stomach (ECC4), breast (MCF7), cervix (HeLa), and prostate (DU145).

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.

BACKGROUND: To 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. METHODS: We 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. RESULTS: The 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. CONCLUSION: The 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.

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.

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.

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.

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.

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.

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.

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).

Bioactive Compounds from Medicinal Plants in Myanmar.

Myanmar is a country with rich natural resources and of these, medicinal plants play a vital role in the primary health care of its population. The people of Myanmar have used their own system of traditional medicine inclusive of the use of medicinal plants for 2000 years. However, systematic and scientific studies have only recently begun to be reported. Researchers from Japan, Germany, and Korea have collaborated with researchers in Myanmar on medicinal plants since 2000. During the past two decades, over 50 publications have been published in peer-reviewed journals. Altogether, 433 phytoconstituents, including 147 new and 286 known compounds from 26 plant species consisting of 29 samples native to Myanmar, have been collated. In this contribution, phytochemical and biological investigations of these plants, including information on traditional knowledge are compiled and discussed.

Anti-metastatic effects of ergosterol peroxide from the entomopathogenic fungus Ophiocordyceps gracilioides on 4T1 breast cancer cells.

Ophiocordyceps gracilioides is an entomoparasitic ascomycetes whose bioactivity has not been examined in detail. In this study, we identified the bioactive compounds ergosterol peroxide (EPO) and ergosterol (ERG) from the MeOH extract of O. gracilioides mycelia related to its anti-cancer effects by targeting the Nuclear Factor kappa B (NF-ĸB)/Signal Transducer and Activator of Transcription 3 (STAT3) inflammatory pathways. Using gene-reporter assays, we demonstrated that EPO markedly inhibits both NF-ĸB and STAT3 activity in 4T1 cells, whereas ERG had limited effect. Consistent with their effects on NF-ĸB and STAT3 activity, EPO, but not ERG, exerted anti-proliferative effects on 4T1 cells. Furthermore, EPO significant inhibited both the migration and invasion of 4T1 cells in vitro, and pre-treatment of 4T1 cells with EPO significantly inhibited the formation of experimental lung metastases in vivo. Collectively, we demonstrated that ERG and EPO can be isolated from O. gracilioides mycelia, and further identified EPO as an active constituent of its anti-metastatic effects through the inhibition of NF-ĸB and STAT3 inflammatory pathways in 4T1 breast cancer cells.

Shanpanootols A-F, diterpenoids from Kaempferia pulchra rhizomes collected in Myanmar and their Vpr inhibitory activities.

Six new isopimarane diterpenoids, shanpanootols A-F (1-6), along with two known analogues, were isolated from the ethyl acetate-soluble extract of Kaempferia pulchra rhizomes collected in Myanmar. The structures of these compounds were elucidated by extensive spectroscopic techniques such as 1D and 2D NMR and HRESIMS. The absolute configuration of 1 was determined by the modified Mosher method. The new isolates (1-6) were tested for their Vpr inhibitory activities against TREx-HeLa-Vpr cells. Shanpanootols C (3) and E (5) inhibited Vpr at doses of 2.5 and 5 µM, respectively.

Rotavirus infection among children under five years of age hospitalized with acute gastroenteritis in Myanmar during 2018-2020 - Multicentre surveillance before rotavirus vaccine introduction.

BACKGROUND: Rotavirus gastroenteritis (RVGE) is a leading cause of severe diarrhea in children under-five worldwide, with the majority of mortality in lower -income countries. This study aimed to provide baseline information on epidemiology of rotavirus and circulating strains before rotavirus vaccine introduction in Myanmar. METHODS: Hospital-based, prospective surveillance was conducted from May 2018 to January 2020 at four sentinel sites; two hospitals in Lower Myanmar, one hospital each in Middle Myanmar and East Myanmar. Children under five years of age hospitalized for acute gastroenteritis were enrolled; demographic and clinical data were collected. Stool samples were screened by ELISA (ProSpecT™ Rotavirus, OXOID-UK) for rotavirus antigen and a subset of ELISA positive samples were genotyped by reverse transcription polymerase chain reaction. RESULTS: Rotavirus was detected in 45.7% (799/1750) of cases enrolled at three sites in May 2018-April 2019 and 42.5% (521/1227) at four sites in May 2019-January 2020. RVGE cases were predominantly male (58.7%; 775/1320) and 92.6% (1223/1320) of RVGE cases occurred in <2 years old. Rotavirus detection was higher in the cold and dry season (November-April). RVGE compared to non-RVGE cases had more frequent vomiting (78.3% Vs 68.1%, p < 0.01), fever (65.8% Vs 61.3%, p = 0.01), severe dehydration (3.6% Vs 2.1%, p < 0.01) and requirement of treatment by IV fluid (58.3% Vs 53.1%, p < 0.01). The most prevalent genotypes identified were G1P[6] (113/359, 31.5%), G1P[8] (94/359, 26.2%) and G2P[4] (33/359, 9.2%). CONCLUSIONS: This study confirms the persistent high prevalence of RVGE among children under-five admitted to hospitals in different parts of Myanmar and the diversity of rotavirus strains over time prior to vaccine introduction. The rotavirus vaccine was introduced nationwide in February 2020 in Myanmar and these data will be important baseline data for post-vaccination monitoring of vaccine impact and circulating strains.

Anti-inflammatory activities of isopimara-8(9),15-diene diterpenoids and mode of action of kaempulchraols B-D from Kaempferia pulchra rhizomes.

Kaempulchraols B-D (2-4), isopimara-8(9),15-diene diterpenoids isolated from Kaempferia pulchra rhizomes collected in Myanmar, were identified as potent NF-κB inhibitors. These compounds were also effective as NO inhibitory agents, with IC50 values of 47.69, 44.97, and 38.17 µM, respectively, without showing any cytotoxicity against LPS-induced RAW264.7 cells. Investigations of the mechanisms of action of 2-4 revealed that they inhibit the NF-κB-mediated transactivation of a luciferase reporter gene, IL-6 production, and COX-2 expression, with an effective dose of 25 µM. Thus, isopimarane diterpenoids are suggested to be potent inhibitors of NF-κB pathways and could be further explored as potential anti-inflammatory lead compounds.