Microjaponin, a new dihydroagarofuranoid sesquiterpene from the stem of Microtropis japonica with antituberculosis activity.

A new dihydroagarofuran-based sesquiterpene, microjaponin (1), was isolated from the stem of Microtropis japonica. Its structure was determined by in-depth spectroscopic and mass-spectrometric analyses. Microjaponin (1) exhibited potent in vitro antituberculosis activity, with an MIC value of 12.5 µg/ml against Mycobacterium tuberculosis H37 Rv.

Biological evaluation of secondary metabolites from the roots of Myrica adenophora.

Bioassay-guided fractionation of the roots of Myrica adenophora led to isolation of 24 known compounds and hitherto unknown compounds, including three A-type proanthocyanidins [adenodimerins A-C], two esters of sucrose [myricadenins A and B ], and the phenolic glycoside 6'-O-galloyl orbicularin. Spectroscopic analyses were used to determine their structures. Adenodimerin A, myricananin C, and myricetin showed strong 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities, with SC50 values of 7.9, 16.3, and 15.9 µM, respectively. Adenodimerin A, myricanone, myricananin C, (-)-myricanol, myricanol 11-O-ß-D-glucopyranoside, and myricetin showed stronger 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging activities than the positive control, with SC50 values of 7.5, 19.6, 12.0, 22.3, 19.6, and 15.6 µM, respectively. 5-Deoxymyricanone, porson, 12-hydroxymyricanone (-)-myricanol, and (+)-galeon exhibited anti-tubercular activity against Mycobacterium tuberculosis H37Rv in vitro and MICs values of 25.8, 40.0, 35.8, 30.0, and 15.0 µg/mL, respectively. Myricadenin A, myricanone, myricananin C, and (-)-myricanol exhibited anti-inflammatory activities in the iNOS assay with EC50 values of 18.1, 1.00, 13.0, and 7.5 µM, respectively.

Three new phenylpropanoids from the roots of Piper taiwanense and their inhibitory activities on platelet aggregation and Mycobacterium tuberculosis.

Bioassay-guided fractionation of the active AcOEt-soluble fraction from the roots of Piper taiwanense has led to the isolation of two new phenylpropanoids, taiwanensols A and B (1 and 2, resp.), a new natural product, taiwanensol C (3), and 3-acetoxy-4-hydroxy-1-allylbenzene (4). The compounds were obtained as two isomer mixtures (1/2 and 3/4, resp.). Their structures were elucidated by spectroscopic analyses, including 1D- and 2D-NMR spectroscopy and mass spectrometry, and by the comparison of their NMR data with those of related compounds. Compounds 1-4 were evaluated for their antiplatelet and antitubercular activities. The mixtures 1/2 and 3/4 showed potent inhibitory activities against platelet aggregation induced by collagen, with IC50 values of 35.2 and 8.8 µM, respectively. In addition, 1/2 and 3/4 showed antitubercular activities against Mycobacterium tuberculosis H37Rv, with MIC values of 30.0 and 48.0 µg/ml, respectively.

Genetic environments of the transferable plasmid-mediated blaCTX-M-3 gene in Serratia marcescens isolates.

In this study, genetic environments of the transferable plasmid-mediated blaCTX-M-3 gene were characterized among 14 isolates of cefotaxime-resistant Serratia marcescens using PCR and BLAST DNA sequence analysis. A total of 3 types of genetic architectures in the regions surrounding this blaCTX-M-3 gene were identified. Type I architecture was characterized by the presence of a complete insertion sequence of tnpA-ISEcp1, identified as interrupting a reverse IS26 sequence in the upstream region of the blaCTX-M-3 gene. A reverse-directional orf477 fragment was located downstream of the blaCTX-M-3 gene, which was in the same direction of the mucA gene. A common region containing the orf513 element was located upstream of the mucA gene. Moreover, a copy of the 3'-CS2 element was located immediately upstream of the orf513 element. A novel complex class 1 integron was characterized by the presence of the dfrA19 gene, which was flanked by two copies of class 1 integrons. This is the first report to describe the dfrA19 gene within a novel complex class 1 integron in S. marcescens isolates from Taiwan. This novel complex class 1 integron structure was located distantly upstream of the blaCTX-M-3 gene.

New pterosin sesquiterpenes and antitubercular constituents from Pteris ensiformis.

Two new pterosin sesquiterpenes, (2S)-13-hydroxypterosin A (1) and (2S,3S)-12-hydroxypterosin Q (2), were isolated from the whole plants of Pteris ensiformis, together with six known compounds. The structures of 1 and 2 were determined through extensive 1D/2D-NMR and MS analyses. Compound 2 exhibited antitubercular activity (MIC 6.25 µg/ml) against Mycobacterium tuberculosis H37 Rv in vitro.

Neolignans and phenylpropanoids from the roots of Piper taiwanense and their antiplatelet and antitubercular activities.

Bioassay-guided fractionation of roots from Piper taiwanense led to isolation of three neolignans, diallylcatechol (1) and neotaiwanensols A, B (2, 3), two diphenylpropanoid ethers, taiwandimerols A, B (4, 5), with one phenylpropanoid, 2,3-diacetoxy-1-methoxy-5-allylbenzene (6), previously unknown in nature, together with 18 known compounds (7-24). Their structures were elucidated by spectroscopic evidence. Among the isolates, hydroxychavicol acetate (7), and 4-allylcatechol (8) showed potent inhibitory activities against platelet aggregation induced by collagen, with IC50 values of 2.1, and 5.3 µM, respectively. Hydroxychavicol acetate (7), 4-allylcatechol (8), and trans-caffeicaldehyde (9) showed antitubercular activities against Mycobacterium tuberculosis H37Rv, with MIC values of 30.3, 27.6, and 25.5 µg/mL, respectively.

Secondary metabolites from the unripe pulp of Persea americana and their antimycobacterial activities.

The fruits of Persea americana (Avocado) are nowadays used as healthy fruits in the world. Bioassay-guided fractionation of the active ethyl acetate soluble fraction has led to the isolation of five new fatty alcohol derivatives, avocadenols A-D (1-4) and avocadoin (5) from the unripe pulp of P. americana, along with 12 known compounds (6-17). These structures were elucidated by spectroscopic analysis. Among the isolates, avocadenol A (1), avocadenol B (2), (2R,4R)-1,2,4-trihydroxynonadecane (6), and (2R,4R)-1,2,4-trihydroxyheptadec-16-ene (7) showed antimycobacterial activity against Mycobacterium tuberculosis H(37)R(V)in vitro, with MIC values of 24.0, 33.8, 24.9, and 35.7 µg/ml, respectively.

Secondary metabolites from the stems of Engelhardia roxburghiana and their antitubercular activities.

Bioassay-guided fractionation of stems of Engelhardia roxburghiana led to isolation of: four diarylheptanoids, engelheptanoxides A-D (1-4); two cyclic diarylheptanoids, engelhardiols A (5) and B (6); one naphthoquinone dimer, engelharquinonol (7); and one 1-tetralone, (4S)-4,6-dihydroxy-1-tetralone (8), along with 24 known compounds (9-32). The structures of 1-8 were by spectroscopic analysis. Compounds 5, 6, 13, 22, and 23 showed antitubercular activity against Mycobacterium tuberculosis H(37)Rv with MIC values of 72.7, 62.1, 9.1, 15.3, and 70.1µM, respectively.

Secondary metabolites from the root of Ehretia longiflora and their biological activities.

Bioassay-guided fractionation of the methanolic extract of the root of Ehretia longiflora (Boraginaceae) afforded eight compounds, ehretiquinone (1), ehretiolide (2), ehreticoumarin (3), ehretilactone A (4), ehretilactone B (5), ehretiamide (6), ehretine (7), and ehretiate (8), together with 12 known compounds (9-20). The relative configuration of 1 was determined by single crystal X-ray diffraction. Among the isolates, 1 and prenylhydroquinone (14) showed antitubercular activity against Mycobacterium tuberculosis strain H37Rv with MIC values of 25.0 and 26.2 µg/mL, respectively. Moreover, 1 exhibited inhibitory effects on N-formylmethionylleucylphenylalanine (fMLP)-induced superoxide production, with IC50 value of 0.36±0.03µM.

Structural elucidation and bioactivity of biflavonoids from the stems of Wikstroemia taiwanensis.

Three new biflavonoids, wikstaiwanones A-C (1-3), along with four known compounds (4-7) were isolated from the stems of Wikstroemia taiwanensis (Thymelaeaceae). Their structures were elucidated by spectroscopic analysis. Compounds 4 and 5 showed antitubercular activity against Mycobacterium tuberculosis with MIC values of 15 µg/mL, respectively.

New flavanones from the leaves of Cryptocarya chinensis and their antituberculosis activity.

Four new flavanones, cryptoflavanones A-D (1-4, resp.), together with eight known compounds, were isolated from the leaves of Cryptocarya chinensis. The structures of these new compounds were determined by spectral analyses. Among the isolated compounds, pinocembrin (5) and cryptocaryone (6) exhibited antituberculosis activity against Mycobacterium tuberculosis H(37) Rv strain in vitro with MIC values of 3.5 and 25.0 µg/ml, respectively.

Antitubercular chromones and flavonoids from Pisonia aculeata.

Three new chromones, pisonins A (1), B (2), and D (4), two new flavonoids, pisonivanone [(2S)-5,7,2'-trihydroxy-8-methylflavanone] (7) and pisonivanol [(2R,3R)-3,7-dihydroxy-5,6-dimethoxyflavanone] (8), one new isoflavonoid, pisonianone (5,7,2'-trihydroxy-6-methoxy-8-methylisoflavone) (9), and five compounds first isolated from nature, namely, pisonins C (3), E (5), and F (6), pisoniamide (10), and pisonolic acid (11), together with 18 known compounds have been isolated from the methanol extract of the combined stem and root of Pisonia aculeata. Among these isolates, 2, 7, 14, 16, and 19 exhibited antitubercular activities (MICs≤50.0 µg/mL) against Mycobacterium tuberculosis H37Rv in vitro.

Secondary metabolites from the root wood of Zanthoxylum wutaiense and their antitubercular activity.

Bioassay-guided fractionation of the root wood of Zanthoxylum wutaiense led to the isolation of five new compounds, wutaipyranol A (1), 8-methoxywutaipyranol A (2), demethoxywutaiensal (3), demethoxywutaiensol (4), and dihydrodemethoxywutaiensol (5), together with six known compounds. Their structures were elucidated by 1D- and 2D-NMR, as well as MS analyses. Among the isolates, wutaipyranol A (1), 8-methoxywutaipyranol A (2), and demethoxywutaiensal (3) exhibited antitubercular activities against Mycobacterium tuberculosis H(37) Rv in vitro, with MIC values of 52.4, 55.6, and 45.8 µg/ml, respectively.

Chemical constituents and antitubercular activity of Formosan Pisonia umbellifera.

Bioassay-guided fractionation of the methanolic extract of the stem of Pisonia umbellifera (Nyctaginaceae) afforded the three new compounds, secopisonic acid (1), 6,8-dimethylisogenistein (2), and (+)- ENT-ficusol (3), and four first isolates from nature, pisoninol I (4), pisoninol II (5), pisoquinoline (6), and pisodienone (7), together with fifteen known compounds. Their structures were elucidated by analysis of spectroscopic data. Seven of these isolates, 3, 7, 12, 16, 18, 20, and 21 showed antitubercular activities against Mycobacterium tuberculosis H37R (V) in vitro, with MIC values ≤ 50 µg/mL.

Use of inverse PCR for analysis of class 1 integrons carrying an unusual 3' conserved segment structure.

By using inverse PCR and DNA sequencing, 13 sul3-associated mutational integrons, 2 defective class 1 integrons, and 1 qnrB2-associated complex sul1-type class 1 integrons were identified in Salmonella enterica serovar Choleraesuis, Pseudomonas aeruginosa, and Enterobacter cloacae, respectively. In addition, conjugation and Southern hybridization demonstrated that unusual class 1 integrons were located on plasmids or integrated into chromosomal DNA. Thus, an inverse PCR assay can be a valuable tool for the analysis of unusual structures of the 3' conserved region of class 1 integrons.

Antitubercular resorcinol analogs and benzenoid C-glucoside from the roots of Ardisia cornudentata.

Bioassay-guided fractionation of the roots of Ardisia cornudentata Mez (Myrsinaceae) led to the isolation of three new compounds, 3-methoxy-2-methyl-5-pentylphenol (1), 3-methoxy-2-methyl-5-(1'-ketopentyl)phenol (2), and cornudoside (3), together with twenty-six known compounds. Their structures were elucidated by analysis of spectroscopic data. Thirteen of these isolates, 1, 2, 4- 6, 9- 15, and 21 showed antitubercular activities against Mycobacterium tuberculosis H37R (V) IN VITRO, with MIC values of 2.5-60 µg/mL. Two alkyl benzoquinones, ardisianone (7) and cornudentanone ( 8), were reported for their selective cytotoxic activity against the NCI-H460 cancer cell line (IC (50) values of 2.3, 2.5 µg/mL).

One-tube loop-mediated isothermal amplification combined with restriction endonuclease digestion and ELISA for colorimetric detection of resistance to isoniazid, ethambutol and streptomycin in Mycobacterium tuberculosis isolates.

In this study, we designed a simple and rapid colorimetric detection method, a one-tube loop-mediated isothermal amplification (LAMP)-PCR-hybridization-restriction endonuclease-ELISA [one-tube LAMP-PCR-HY-RE-ELISA] system, to detect resistance to isoniazid, ethambutol and streptomycin in strains of Mycobacterium tuberculosis isolated from clinical specimens. The clinical performance of this method for detecting isoniazid-resistant, ethambutol-resistant and streptomycin-resistant isolates of M. tuberculosis showed 98.9%, 94.3% and 93.8%, respectively. This assay is rapid and convenient that can be performed within one working day. One-tube LAMP-PCR-HY-RE-ELISA system was designed based on hot spot point mutations in target drug-resistant genes, using LAMP-PCR, hybridization, digestion with restriction endonuclease and colorimetric method of ELISA. In this study, LAMP assay was used to amplify DNA from drug-resistant M. tuberculosis, and ELISA was used for colorimetrical determination. This assay will be a useful tool for rapid diagnosis of mutant codons in strains of M. tuberculosis for isoniazid at katG 315 and katG 463, ethambutol at embB 306 and embB 497, and streptomycin at rpsL 43.

A novel dimeric coumarin analog and antimycobacterial constituents from Fatoua pilosa.

One novel dimeric coumarin analog, fatouapilosin (1), together with 18 known compounds, have been isolated from the whole plants of Fatoua pilosa. The structures of these isolates were elucidated by means of spectroscopic techniques (UV, IR, MS, 1H- and 13C-NMR, DEPT, COSY, NOESY, HSQC, HMBC, and MS analyses). Among the tested compounds 2-14, scopoletin (3), isobavachalcone (12), and (E)-1-[2,4-dihydroxy-3-(3-methylbut-2-enyl)phenyl]-3-(2,2-dimethyl-8-hydroxy-2H-benzopyran-6-yl)prop-2-en-1-one (14) exhibited the strongest antimycobacterial activities against Mycobacterium tuberculosis H(37)Rv, with MIC values of 42, 18, and 30 microg/ml, respectively.

Secondary metabolites and antimycobacterial activities from the roots of Ficus nervosa.

Bioassay-guided fractionation of the active AcOEt-soluble layer led to the isolation of two new pyranocoumarins, 3-hydroxyxanthyletin (1) and 3-methoxyxanthyletin (2), along with 22 known compounds including four simple coumarins, i.e., xanthyletin (3), umbelliferone (4), scopoletin (5), and (+)-(S)-marmesin (6); nine flavonoids, i.e., carpachromene (7), parvisoflavone B (8), alpinumisoflavone (9) genistein (10), 2'-hydroxygenistein (11), prunetin (12), cajanin (13), apigenin (14), and (2S)-naringenin (15); three benzenoids, i.e., 4-hydroxybenzaldehyde (16), vanillin (17), and (S)-lasiodiplodin (18); five steroids, i.e., ergosterol peroxide (19), a mixture of 6beta-hydroxystigmast-4-en-3-one (20) and 6beta-hydroxystigmasta-4,22-dien-3-one (21), and a mixture of beta-sitosterol (22) and stigmasterol (23); and one triterpenoid, i.e., oleanolic acid (24) from the roots of Ficus nervosa. Their structures were elucidated on the basis of extensive 1D- and 2D-NMR as well as MS analyses. Among these isolates, 3-hydroxyxanthyletin (1), genistein (10), prunetin (12), and (2S)-naringenin (15) showed antimycobacterial activities against Mycobacterium tuberculosis H(37)R(V) in vitro with MIC values of 16, 35, 30, and < or =2.8 microg/ml, respectively.

Secondary metabolites from the roots of Litsea hypophaea and their antitubercular activity.

Bioassay-guided fractionation of the roots of Litsea hypophaea led to the isolation of seven new butanolides, namely, litseakolides H-N (1-7), all with the 3R,4S configuration, as well as three new biarylpropanoids, hypophaone (8), hypophaol (9), and hypophane (10), and 15 known compounds. The structures of 1-10 were determined by means of spectroscopic analysis. Litseakolide L (5) and N-trans-feruloylmethoxytyramine (11) showed antitubercular activity against Mycobacterium tuberculosis strain H(37)Rv, with MIC values of 25 and 1.6 microg/mL, respectively.