Constituents of Caryopteris incana and their antibacterial activity

Two new compounds named caryocanolide (1), and caryocanoside A (2), together with nine known compounds (3–11) were isolated from the whole plant of Caryopteris incana. These structures were determined mainly on the basis of 2D nuclear magnetic resonance and high resolution fast atom bombardment mass spectroscopy data. Furthermore, the isolated compounds (1, 2, 4–11) were tested for their antibacterial activity. Compound 1 exhibited moderate antimicrobial activity against Bacillus subtilis with a minimum inhibitory concentration value of 35.7 μM.     

Zeaoxazolinone,a new antifungal agent from Zea mays roots

A new 7-methoxy-2-benzoxazolinone dimer named zeaoxazolinone (2), together with four known compounds; 9-Z-hexadecenoic acid (1), 6-methoxy-benzoxazolinone (3), gallic acid (4), and β-sitosterol-3-O-β-d-glucopyranoside (5) were isolated from Zea mays L. roots. The structural elucidation of isolated metabolites was established on the basis of UV, IR, 1D, 2D NMR, and MS spectral analyses. Compound 2 exhibited a potent antifungal activity against Aspergillus flavus, Fusarium oxysporum, and Candida albicans.     

Antibacterial substances from Albizia myriophylla wood against cariogenic Streptococcus mutans

Albizia myriophylla has been used for long by Thai traditional healers as an important ingredient herb in Thai herbal formulas for caries. In this study, three flavonoids lupinifolin (6), 8-methoxy-7,3′,4′-trihydroxyflavone (7), and 7,8,3′,4′-tetrahydroxyflavone (8), a triterpenoid lupeol (3) as well as four sterols β-sitosterone (1), stigmasta-5,22-dien-3-one (2), β-sitosterol (4), and stigmasterol (5) were isolated from A. myriophylla wood. The antibacterial activity of these compounds against Streptococcus mutans ATCC 25175 was performed using broth microdilution method. All compounds exhibited antibacterial activity against S. mutans with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) ranging from 1–256 and 2–256 μg/ml, respectively. Among the isolated compounds, lupinifolin (6) was found to be the most potent with MIC and MBC of 1 and 2 μg/ml, respectively. Lupinifolin (6) also showed a strong activity against ten clinical isolates of S. mutans with MIC and MBC ranging from 0.25–2 and 0.5–8 μg/ml, respectively. These results reported the bioactive ingredients of A. myriophylla which support its ethnomedical claims as well. Lupinifolin (6) may have a potential to be a natural anticariogenic agent.     

Five new sesquiterpene lactones from Inula hupehensis

Four new pseudoguaianolides (1–4), one new guaianolide (5), together with ten known compounds (6–15) were isolated from the aerial parts of Inula hupehensis. Their structures were elucidated mainly on the basis of 1D and 2D spectroscopic methods and circular dichroism analysis. In addition, compounds 1–10 and 13 were tested for their inhibitory effects against LPS-induced NO production in RAW264.7 macrophages. Compounds 2, 6, 8 and 9 exhibited significant inhibitory activities with IC₅₀ values in the range of 0.6–6.6 μM.     

Flavonoids from Millettia nitida var. hirsutissima with their anticoagulative activities and inhibitory effects on NO production

Two new compounds, (2R)-7,3′-dihydroxy-6,4′-methoxyflavan (1) and (3R)-7,4′-dihydroxy-2′-methoxyisoflavan (2), along with 12 known flavonoids (3–14), were isolated from the vine stems of Millettia nitida var. hirsutissima. The structures of the isolated compounds were elucidated based on spectroscopic analyses and comparison of literature data. All of the isolates were evaluated for their effects on in-vitro anticoagulative assay and on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated RAW264.7 macrophages. As a result, all compounds showed weak antiplatelet aggregation activities and compounds 4, 5, 7, 8 and 9 demonstrated antithrombin activity with a good dose–effect relationship from 5 to 100 μg mL^?1 in rabbit plasma. Compounds 8, 9, 10 and 14 exhibited inhibitory effects on LPS-induced NO production in RAW264.7 macrophages with IC₅₀ values of 4.79 ± 0.20, 8.23 ± 0.35, 5.23 ± 0.11 and 6.30 ± 0.30 μg mL^?1, respectively.     

Phenylethanoid and flavone glycosides from Ruellia tuberosa L.

A new phenylethanoid glycoside, isocassifolioside (8), and two new flavone glycosides, hispidulin 7-O-α-l-rhamnopyranosyl-(1′″ → 2″)-O-β-d-glucuronopyranoside (11) and pectolinaringenin 7-O-α-l-rhamnopyranosyl-(1′″ → 2″)-O-β-d-glucuronopyranoside (12) were isolated from the aerial portions of Ruellia tuberosa L., together with verbascoside (1), isoverbascoside (2), nuomioside (3), isonuomioside (4), forsythoside B (5), paucifloside (6), cassifolioside (7), hispidulin 7-O-β-d-glucuronopyranoside (9) and comanthoside B (10). The structure elucidations were based on analyses of chemical and spectroscopic data including 1D- and 2D-NMR. The isolated compounds 1–12 exhibited radical scavenging activity using ORAC assay.     

Anti-inflammatory and antioxidant activities of phenolic compounds from Desmodium caudatum leaves and stems

Four flavanonols (1–4), one xanthone (5), and three flavonoid glycosides (6–8), were isolated from the leaves and stems of Desmodium caudatum. Their structures were elucidated by comparing spectroscopic data with reported values. The anti-inflammatory activity of the isolated compounds was investigated in lipopolysaccharide (LPS)-stimulated bone marrow-derived dendritic cells. Among them, compounds 1 and 2 exhibited inhibitory effects on LPS-induced IL-6, IL-12 p40, and TNF-α production with IC₅₀ values ranging from 6.0 to 29.4 μM. Compound 5 exhibited 1,1-diphenyl-2-picrylhydrazyl radical and intracellular reactive oxygen species scavenging activity in human HaCaT keratinocytes. These results warrant further studies of the potential anti-inflammatory and antioxidant benefits of compounds from D. caudatum.     

Isochaetomium A2, a new bis(naphthodihydropyran-4-one) with antimicrobial and immunological activities from fungus Chaetomium microcephalum

Isochaetomium A₂ (1), a new bis(naphthodihydropyran-4-one), along with chaetochromins A (2) and B (3), was isolated from the solid-state fermented rice culture of Chaetomium microcephalum. The structure of compound 1 was elucidated on the basis of 1D and 2D NMR spectral data, and the relative configuration was confirmed by CD spectrum. Compounds 1–3 possessed significant antimicrobial activity against Escherichia coli 1.044, Staphylococcus aureus 1.252, and Bacillus subtilis 1.079. Moreover, compounds 1–3 showed obvious inhibitory effects on mouse spleen cell proliferation with successive IC₅₀ values of 0.52, 0.19, and 0.24 μM.     

In vitro antimicrobial activity of o-phenylenediamine-tert-butyl-N-1,2,3-triazole carbamate analogs

In an attempt to design and synthesize effective antimicrobial agents using click chemistry, mono- and di-alkyne-substituted monoboc protected o-phenylenediamines were reacted with different substituted aryl azides which yielded 18 new compounds (4a–4k and 5a–5f, 5l). Structures of all newly synthesized compounds were established by ¹H and ¹³C NMR analysis. The intermediate compound 1 was also confirmed by X-ray crystallography. The title compounds were screened for their antibacterial activity against Gram +ve bacteria (Staphylococcus aureus and Enterococcus faecalis), Gram ?ve bacteria (Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa), and their antifungal profile were tested on (Candida tropicalis, Candida albicans, Candida krusei, and Cryptococcus neoformans) as well as on molds such as (Aspergillus niger, Aspergillus fumigatus). The compounds 4k and 5f both showed maximum potency against S. aureus (ATCC 25323) strain with MIC value of 6.25 µg/ml, which is comparable with standard drug ciprofloxacin (MIC 6.25 µg/ml) while remaining compounds showed moderate to weak activity. Further, all compounds showed average antifungal activity in the range of 100–200 µg/ml.     

Phenolic compounds with IL-6 inhibitory activity from Aster yomena

A new biflavonoid, named asteryomenin (1), as well as six known phenolic compounds, esculetin (2), 4-O-β-d-glucopyranoside-3-hydroxy methyl benzoate (3), caffeic acid (4), isoquercitrin (5), isorhamnetin-3-O-glucoside (6), and apigenin (7) were isolated from the aerial parts of Aster yomena. The structures of compounds (1–7) were identified based on 1D and 2D NMR, including ¹H–¹H COSY, HSQC, HMBC and NOESY spectroscopic analyses. Compounds 2–7 were isolated from this plant for the first time. For these isolates, the inhibitory activity of IL-6 production in the TNF-α stimulated MG-63 cell was examined. Among these isolates, compounds 4 and 7 appeared to have potent inhibitory activity of IL-6 production in the TNF-α stimulated MG-63 cell, while compounds 1–3 and 5–6 showed moderate activity.     

Cytotoxic and anti-inflammatory constituents from the seeds of Descurainia sophia

A new sinapoyl glycoside, 1,3-di-O-sinapoyl-β-d-glucopyranose (1) along with 13 known compounds, including, sinapoyl glycosides (2 and 3), cardenolide glycoside (4), flavonoids (5–10), lignan (11), phenolic acids (12 and 13), and phytosterol (14), were isolated from the seeds of Descurainia sophia by chromatographic separation methods. The structures of 1–14 were determined by the interpretation of spectroscopic data as well as by comparison of that data with previously reported values. Compounds 2, 3, 5, 6, and 11 were identified in and isolated from this plant for the first time in this study. All isolates were evaluated for in vitro cytotoxic activities against seven human cancer cell lines and for in vitro anti-inflammatory potential using LPS-stimulated RAW264.7 murine macrophages. Compound 4 showed potent cytotoxicity (IC₅₀ values ranging from 0.034 to 0.596 μM) against all human cancer cell lines tested and was identified as the main active cytotoxic constituent of this plant. Compound 8 (ED₅₀ = 5.45 μM) and 11 (ED₅₀ = 10.02 μM) exerted dose-dependent inhibitory effects on NO production in LPS-stimulated RAW264.7 cells.     

Synthesis and biological activity of novel Schiff bases derived from metronidazole

A number of novel Schiff bases (5a–i) and (7a–d) derived from metronidazole were synthesized. Reaction of 2-(2-methyl-5-nitro-imidazol-1-yl)-ethyl ester toluene-4-sulfonate with 4-hydroxybenzaldehyde and with 3-hydroxybenzaldehyde in the presence of a base afforded 4-(2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethoxy)benzaldehyde (5) and 3-(2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethoxy)benzaldehyde (7), respectively. The reaction of aldehydes 5 and 7 with a number of primary aromatic amines produced Schiff bases 5a–i and 7a–d, respectively. Structures of these compounds were confirmed through different spectroscopic methods such as ¹H-NMR, ¹³C-NMR, mass spectrometry, and also by elemental analyses. The prepared compounds were evaluated in vitro for their antigiardial, anti-trichomonal, antibacterial, and antifungal activities. Compounds 5e, 5g, 5i, 7a, 7b, 7c, and 7d exhibited remarkable antigiardial activity and were found to be more active than metronidazole with IC₅₀ of 7.2, 3.3, 1.5, 5.8, 4.5, 2.9, and 3.8 µg/mL, respectively. Compounds 5a and 5c also exhibited antigiradial activity with similar IC₅₀ values compared to the reference drug metronidazole with IC₅₀ of 7.2 µg/mL. The other compounds 5b, 5d, 5f, and 5 h also showed antigiardial activity but with higher IC₅₀ compared to the reference drug. Compounds were also tested for their anti-trichomonal activity, they, however, exhibited higher IC₅₀ compared to the reference drug metronidazole (7.4 µg/mL), except for compound 5a which exhibited anti-trichomonal activity with an IC₅₀ of 6.3 µg/mL. On the bases of preliminary screening, the newly synthesized compounds exhibited moderate to potent antimicrobial activities. Compound 5e inhibited the growth of Methicillin resistant Staphylococcus aureus (MRSA) and Bacillus cereus and compound 5c inhibited Candida Pathogenic fungus at 50 μg/mL compared with the positive control (Nystatin) which inhibits Candida at 25 μg/mL.     

Anticandidiasis agents from a Tanzanian plant, Combretum zeyheri

Combretum zeyheri Sond (Combretaceae) has been reported to exhibit anticandida activity against Candida kruzei, C. albicans, and C. parapsilosis; however, the active constituents have not been isolated so far. A bioactivity-guided fractionation of MeOH extract of C. zeyheri resulted in the isolation of triterpenoids, ursolic acid (1.1), oleanolic acid (1.2), maslinic acid (2.1), 2α,3β-dihydroxyurs-12-en-28-oic acid (2.2), 6β-hydroxymaslinic acid (3), and terminolic acid (4). These compounds were characterized on the basis of their 1D, 2D NMR, ESI-MS and FT-IR spectroscopic data. All the isolated compounds, 1.2, 2.1, 2.2, 3, and 4 except ursolic acid (1.1) are being reported for the first time from C. zeyheri. Later, the isolated triterpenoids (1–4) were evaluated for their anticandida activity against the three strains of C. albicans and all compounds showed anticandida activity of which terminolic acid (4) was most active. Furthermore, structure–activity relationship of isolated triterpenoids (1–4) was studied, which showed that triterpenoids of oleanane and ursane having 2α,3β,23-trihydroxyl group are more active.     

Three new diphenylpropanes from Celastrus hindsii

Three new diphenylpropanes, Hindsiipropane A–C (1–3), together with one known arylpropyl quinone Griffithane D (4), were isolated from Celastrus hindsii. Their structures were established by 1D and 2D nuclear magnetic resonance spectroscopic analysis, and mass spectroscopy. Compound 4 was firstly obtained in this genus. All the isolated compounds were evaluated in vitro for cytotoxicity against four human tumor cell lines (A549, HCT116, MDA-MB-231, BEL7404) by the MTT assay.     

Phenolic and iridoid glycosides from the rhizomes of Cyperus rotundus L.

Two new iridoid glycosides, rotunduside A (1) and rotunduside B (2), along with four known compounds, 6′′-O-p-coumaroylgenipin gentiobioside (3), isoaragoside (4), chionoside A (5), and helioside C (6) were isolated from the rhizomes of Cyperus rotundus L. Their chemical structures were determined by application of spectroscopic (NMR, MS) and chemical methodologies. The macrophages respiratory burst (MRB) inhibitory activity of all the isolated compounds was reported. Compound 2 showed marginal inhibitory activity against MRB in the test with IC₅₀ value of approximately 31 μM.     

Aaptamines,marine spongean alkaloids,as anti-dormant mycobacterial substances

A new aaptamine class alkaloid, designated 2-methoxy-3-oxoaaptamine (1), together with seven known aaptamines (2–8) were isolated from a marine sponge of Aaptos sp. as anti-mycobacterial substances against active and dormant bacilli. The chemical structure of 1 was determined on the basis of spectroscopic analysis. Compound 1 was anti-mycobacterial against Mycobacterium smegmatis in both active growing and dormancy-inducing hypoxic conditions with a minimum inhibitory concentration (MIC) of 6.25 μg/ml, and compounds 2, 5, 6, and 7 showed anti-mycobacterial activities under hypoxic condition selectively, with MIC values of 1.5–6.25 μg/ml.     

New diterpenoids with estrogen sulfotransferase inhibitory activity from Leonurus sibiricus L.

Four new diterpenoids (1–4), along with eight known diterpenoids (5–12) were isolated from the acetone extract of Leonurus herb (aerial parts of Leonurus sibiricus L.). The structures of the compounds were determined by spectroscopic methods. Among the isolated compounds, compounds 2, 3, 8, 9 and 10 showed inhibitory activity against human liver cytosol estrogen sulfotransferase (E-ST), which plays a key role in the maintenance of cellular estrogen levels. Compound 2 showed the strongest activity with an IC₅₀ value of 7.9 μM, which is comparable to the activity of the positive control, meclofenamic acid (IC₅₀ 5.4 μM).     

Anti-Helicobacter pylori xanthones of Garcinia fusca

A new geranylated xanthone derivative, fuscaxanthone I (1), along with nine xanthones (2–9 and 11), a biphenyl (10) and three biflavonoids (12–14) were isolated from the roots of Garcinia fusca Pierre. Compounds 8, 10 and 11–14 were reported from this plant species for the first time. Their structures were elucidated by spectroscopic analyses, including 1D- and 2D-NMR and MS. The isolated compounds were evaluated for antibacterial activity against Helicobacter pylori. Cowaxanthone (5) and fukugiside (14) exhibited stronger inhibitory activity against H. pylori DMST reference strain at MICs 4.6 and 10.8 μM, respectively, than that of the control metronidazole. Isojacareubin (8) displayed the most potent activity against H. pylori HP40 clinical isolate with MIC 23.9 μM, which was approximately two times greater than that of the standard drug amoxicillin.     

Furostanol glycosides from the rhizomes of Helleborus orientalis

Eight new furostanol glycosides (1–8), together with two known ones (9 and 10), have been isolated from a glycoside-enriched fraction prepared from the rhizomes of Helleborus orientalis (Ranunculaceae). The structures of 1–8 were determined on the basis of extensive spectroscopic analysis, including 2D NMR, and the results of hydrolytic cleavage. The isolated compounds were evaluated for their cytotoxic activity against HSC-2 cells.     

Synthesis and anti-HIV-1 screening of novel N′-(1-(aryl)ethylidene)-2-(5,5-dioxido-3-phenylbenzo[e]pyrazolo[4,3-c][1,2]thiazin-4(1H)-yl)acetohydrazides

A novel series of N′-(1-(aryl)ethylidene)-2-(5,5-dioxido-3-phenylbenzo[e]pyrazolo[4,3-c][1,2]thiazin-4(1H)-yl)acetohydrazides was synthesized. The synthesis was carried out by thermal method as well as ultrasonic bath to reduce reaction time and to enhance product yields. The synthesized compounds were characterized by spectroscopic techniques like NMR, infrared and EIMS. The structure of compound 5w was elucidated by X-ray crystallography. The titled compounds were evaluated for anti-human immunodeficiency virus type 1 (anti-HIV-1) and cytotoxic activities. Biological studies indicated that amongst these compounds, 5a, b, j, h and i showed the activity with median effective concentration (EC₅₀) values less than 20 μM. Compound 5i exhibited the most potent anti-HIV-1 activity (EC₅₀ = 3.2 μM) while 5h showed anti-HIV-1 activity (EC₅₀ = 3.8 μM) with no toxicity at all in primary human lymphocytes, CEM and VERO cells.