Semi-preparative High-performance Liquid Research Articles

Relay PHOS: Ligands with Fluxional Chirality in Asymmetric Palladium-Catalyzed Allylic Alkylation.

A modular route toward the synthesis of P,N ligands containing a fluxional group along the pyrazoline ring core is described. The racemic ligands were accessed in three steps from commercially available fluoroacetophenone in overall yields ranging from 18 to 76%. The enantiopure ligands were obtained using semi-preparative chiral high-performance liquid chromatography and chiral enantioselective phase-transfer catalysis. The effectiveness of the new ligands was assessed in palladium-catalyzed allylic alkylation with diphenylpropenyl acetate and dimethylpropenyl acetate. Under optimized conditions, diphenylpropenyl acetate underwent alkylation with dimethyl malonate in 98% yield and 94% ee. In general, the enantioselectivity for the product correlates with the size of the ligand fluxional group; the larger the fluxional group, the higher the selectivity.

In vitro analysis of quercetin-like compounds from mistletoe Dendrophthoe pentandra (L.) Miq as a potential antiviral agent for Newcastle disease

Background Recent evidence suggests that some flavonoid compounds obtained from crude methanol extract of mistletoe leaves (Dendrophthoe pentandra L. Miq), also known as Benalu Duku (BD), have antimicrobial effects. Thus, the plant has the potential to eliminate viruses that may cause outbreaks in chicken farms. This study aimed to prove the in vitro ability of flavonoid compounds, namely quercetin-like compounds (QLCs), to eliminate field viruses, specifically the Newcastle disease virus (NDV). Methods This research was performed in two stages. An in vitro test was used with a post-test of the control groups designed at a significance of 0.05. BD leaves (5 kg) were extracted using a maceration method with methanol and then separated into hexane, chloroform, ethyl acetate, and methanol fractions. The final extracted products were separated using semi-preparative high-performance liquid chromatography (HPLC) to obtain QLCs. The QLCs were identified and compared with quercetin using HPLC, proton and carbon nuclear magnetic resonance spectrometry, Fourier transform infrared spectrophotometry and ultra-performance liquid chromatography-mass spectrometry. The activity of QLCs was tested in vitro against the NDV at a virulence titter of 10−5 Tissue Culture Infectious Dose 50% (TCID50) in chicken kidney cell culture. Results Solutions of 0.05% (w/v) QLCs were discovered to have antiviral activity against NDVs, with an average cytopathogenic effect antigenicity at a 10−5 dilution (p<0.05). Conclusions QLCs from flavonoids from the leaves of BD have in vitro antiviral bioactivity against NDV at a virulence titter of 10-5 Tissue Culture Infectious Dose 50% (TCID50) in chicken kidney cell culture. QLCs may have the potential to be developed as medicinal compounds for the treatment of other human or animal viral infections.

In vitro analysis of quercetin-like compounds from mistletoe Dendrophthoe pentandra (L.) Miq as a potential antiviral agent for Newcastle disease

Background Recent evidence suggests that some flavonoid compounds obtained from crude methanol extract of mistletoe leaves (Dendrophthoe pentandra L. Miq), also known as Benalu Duku (BD), have antimicrobial effects. Thus, the plant has the potential to eliminate viruses that may cause outbreaks in chicken farms. This study aimed to prove the in vitro ability of flavonoid compounds, namely quercetin-like compounds (QLCs), to eliminate field viruses, specifically the Newcastle disease virus (NDV). Methods This research was performed in two stages. An in vitro test was used with a post-test of the control groups designed at a significance of 0.05. BD leaves (5 kg) were extracted using a maceration method with methanol and then separated into hexane, chloroform, ethyl acetate, and methanol fractions. The final extracted products were separated using semi-preparative high-performance liquid chromatography (HPLC) to obtain QLCs. The QLCs were identified and compared with quercetin using HPLC, proton and carbon nuclear magnetic resonance spectrometry, Fourier transform infrared spectrophotometry and ultra-performance liquid chromatography-mass spectrometry. The activity of QLCs was tested in vitro against the NDV at a virulence titter of 10−5 Tissue Culture Infectious Dose 50% (TCID50) in chicken kidney cell culture. Results Solutions of 0.05% (w/v) QLCs were discovered to have antiviral activity against NDVs, with an average cytopathogenic effect antigenicity at a 10−5 dilution (p<0.05). Conclusions QLCs from flavonoids from the leaves of BD have in vitro antiviral bioactivity against NDV at a virulence titter of 10-5 Tissue Culture Infectious Dose 50% (TCID50) in chicken kidney cell culture. QLCs may have the potential to be developed as medicinal compounds for the treatment of other human or animal viral infections.

Two new pinophol derivatives from endophytic fungus Penicillium herquei JX4 hosted in Ceriops tagal

An OSMAC strategy was used to study secondary metabolites and anti-inflammatory activities of the endophytic fungus Penicillium herquei JX4 hosted in Ceriops tagal. The PDB ferment of fungus P. herquei JX4 was isolated, purified, and identified by using silica gel column chromatography, gel column chromatography, octadecylsilyl(ODS) column chromatography, and semi-preparative high-performance liquid chromatography. Two new pinophol derivatives, pinophol H(1) and pinophol I(2) were isolated and identified, and they were evaluated in terms of the inhibitory activities against the nitric oxide(NO) production induced by lipopolysaccharide(LPS) in mouse macrophage RAW264.7 cells. The results showed that compound 1 had significant inhibitory activity on NO production, with an IC_(50) value of 8.12 μmol·L~(-1).

In vitro analysis of quercetin-like compounds from mistletoe Dendrophthoe pentandra (L.) Miq as a potential antiviral agent for Newcastle disease

Background Recent evidence suggests that some flavonoid compounds obtained from crude methanol extract of mistletoe leaves (Dendrophthoe pentandra L. Miq), also known as Benalu Duku (BD), have antimicrobial effects. Thus, the plant has the potential to eliminate viruses that may cause outbreaks in chicken farms. This study aimed to prove the in vitro ability of flavonoid compounds, namely quercetin-like compounds (QLCs), to eliminate field viruses, specifically the Newcastle disease virus (NDV). Methods This research was performed in two stages. An in vitro test was used with a post-test of the control groups designed at a significance of 0.05. BD leaves (5 kg) were extracted using a maceration method with methanol and then separated into hexane, chloroform, ethyl acetate, and methanol fractions. The final extracted products were separated using semi-preparative high-performance liquid chromatography (HPLC) to obtain QLCs. The QLCs were identified and compared with quercetin using HPLC, proton and carbon nuclear magnetic resonance spectrometry, Fourier transform infrared spectrophotometry and ultra-performance liquid chromatography-mass spectrometry. The activity of QLCs was tested in vitro against the NDV at a virulence titter of 10−5 Tissue Culture Infectious Dose 50% (TCID50) in chicken kidney cell culture. Results Solutions of 0.05% (w/v) QLCs were discovered to have antiviral activity against NDVs, with an average cytopathogenic effect antigenicity at a 10−5 dilution (p<0.05). Conclusions QLCs from flavonoids from the leaves of BD have in vitro antiviral bioactivity against NDV at a virulence titter of 10-5 Tissue Culture Infectious Dose 50% (TCID50) in chicken kidney cell culture. QLCs may have the potential to be developed as medicinal compounds for the treatment of other human or animal viral infections.

Chiral Hydroxy Metabolite of Mebendazole: Analytical and Semi-Preparative High-Performance Liquid Chromatography Resolution and Chiroptical Properties.

Mebendazole (MBZ) is a benzimidazole carbamate anthelmintic used worldwide for the treatment and prevention of parasitic disorders in animals and humans. A large number of in vivo and in vitro studies have demonstrated that MBZ also has anticancer activity in multiple types of cancers. After oral administration, the phenylketone moiety of MBZ is rapidly reduced to the hydroxyl group to form the chiral hydroxy metabolite (MBZ-OH). To the best of our knowledge, there is no information in the literature on the stereochemical course of transformation and the anthelmintic and antitumor activity of individual enantiomers of MBZ-OH. In the present study, we describe in detail the direct HPLC resolution of MBZ-OH on a 100 mm × 4.6 mm Chirapak IG-3 column packed with 3 μm silica particles containing amylose (3-chloro-5-methylphenylcarbamate) as a selector. At 25 °C and using pure methanol as the mobile phase, the enantioseparation and resolution factors were 2.38 and 6.13, respectively. These conditions were scaled up at a semi-preparative scale using a 250 mm × 10 mm Chiralpak IG column to isolate multi-milligram amounts of both enantiomeric forms of the chiral metabolite. The chiroptical properties of the collected enantiomers were determined and, through a theoretical study, were related to the more stable conformations of MBZ-OH. The first and second eluted enantiomers were dextrorotatory and levorotatory, respectively, in dimethylformamide solution. Finally, by recording the retention factors of the enantiomers as the water content in the water-acetonitrile mobile phases was progressively varied, U-shaped retention maps were generated, indicating a dual and competitive hydrophilic interaction liquid chromatography and reversed-phase liquid chromatography retention mechanism on the Chirapak IG-3 chiral stationary phase.

Secondary Metabolites from the Mangrove-derived Fungus Trichoderma sp.

Background:: Secondary metabolites from the mangrove-derived fungi have great potential to produce natural products with novel structures and significant biological activities. Objective:: The objective of this study was to isolate and identify the secondary metabolites from the mangrove-derived fungus Trichoderma sp. WHUF0342, and evaluate their antibacterial activities. Methods:: The compounds were isolated and purified by silica gel column chromatography, Sephadex LH-20 gel chromatography, and semi-preparative high-performance liquid chromatography (HPLC). Their structures were elucidated by comparing the NMR and MS spectroscopic data with those of literature. The antibacterial activity were evaluated by modified broth microdilution assay. Results:: Eight compounds were isolated from the fermented extracts of the fungus Trichoderma sp. WHUF0342 and identified as chaxine B (1), nafuredin (2), dichlorodiaportin (3), ferulaic acid (4), bis(2-ethylhexyl) benzene-1,2-dicarboxylate (5), methyl 4-hydroxyphenylacetate (6), 4- hydroxyphenyl acetate (7), and 4-hydroxyphenylethyl acetate (8). Chaxine B (1) showed antibacterial activity against the phytopathogenic bacterium Ralstonia solanacearum with a minimum inhibitory concentration (MIC) value of 16 μg/mL. The antibacterial activity against plant pathogen of compound 1 was reported for the first time in this study. Conclusion:: This study not only enriched the secondary metabolites of mangrove-derived fungi but also provided a valuable resource for the prevention of agricultural pathogen infections.

Identification of major degradation products of Clorsulon drug substance including its degradation pathways by high resolution mass spectrometry and NMR

Clorsulon is an effective anthelmintic drug substance extensively used in the treatment of parasitic infestations in both cattle and sheep. An in-depth investigation of Clorsulon’s degradation products (DPs) was carried out through forced degradation study to comprehend its degradation path. A total of eight degradation products were separated under various stress degradation conditions. Structural elucidation of these DPs was conducted using ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS), and their fragmentation patterns were compared to that of the parent compound. Adequate amount of DP-4 was isolated and purified by semi-preparative high-performance liquid chromatography (HPLC) methods. Subsequently, it was examined in detail using both 1D and 2D NMR (nuclear magnetic resonance spectroscopy). Most probable mechanistic pathways for the formation of degradation products under various stress degradation conditions were proposed to better understand the degradation profile. Based on the results of the stress study, Clorsulon drug substance was found to be unstable under photolytic and oxidative conditions. Understanding Clorsulon's degradation pathway is essential for determining shelf-life prediction of the finished product, safety and efficacy assurance, and guiding the development of stable, high-quality formulations.

Cytotoxic Secondary Metabolites from the Ascomycetous Fungus Pseudogymnoascus roseus

Background: Fungi found in unique and competitive environments are abundant in bioactive compounds. Objective: The objective of this study is to isolate and identify secondary metabolites from fungi of unique ecological niches and evaluate their cytotoxicity. Methods: The compounds were isolated and purified using silica gel column chromatography, Sephadex LH-20 gel chromatography, and semi-preparative high-performance liquid chromatography (HPLC). The structures of the isolated compounds were determined using NMR and MS. The cytotoxic activities of these compounds were tested by the MTS assay. Results: Three diphenyl ethers, dechlorodihydromaldoxin (1), violaceol-I (2) and violaceol-II (3), one quinolinone compound, 2-(2-heptenyl)-3-methyl-4(1H)-quinolinone (4), and one α-pyrone nafuredin (5) were isolated from the fermented extracts of Pseudogymnoascus roseus S161. Compound 1 showed modest cytotoxicity against two human tumor cell lines A549 and MCF-7, with IC50 values of 87.12 and 51.07 µM, respectively. Conclusion: Five compounds were isolated from the fungus P. roseus S161. Compound 1 showed moderate cytotoxicity. This study provided a basis for the development of antitumor drugs.

Active constituents of essential oil from Curcuma phaeocaulis for treatment of dysmenorrhea

This study aims to identify the active constituents of essential oil from the rhizomes of Curcuma phaeocaulis for the treatment of dysmenorrhea. The compounds were separated and purified by molecular distillation, silica gel and Sephadex LH-20 column chromatography, preparative thin layer chromatography, and semi-preparative high performance liquid chromatography. Their structures were identified by mass spectrometry and nuclear magnetic resonance spectroscopy. The animal model of primary dysmenorrhea and the contraction model of isolated uterine smooth muscle of rats were established to examine the active constituents in the essential oil for treating dysmenorrhea. Six sesquiterpenes were isolated and identified as dehydrocommiterpene A(1), comosone Ⅱ(2), 5α(H)-eudesma-3(4),7(11)-dien-9β-ol-6-one(3), guaia-6(7)-en-11-ol(4), curcumenol(5), and isocurcumenol(6), among which compound 1 was a novel compound. The animal experiments showed that the essential oil from C. phaeocaulis significantly lowered the level of PGF_(2α) in uterine tissue compared with the model group. The experiment with the contraction model of isolated uterine smooth muscle demonstrated that the components with high boiling points outperformed those with low boiling points in relaxing the uterine smooth muscle, and compounds 1, 2, 5, and 6 isolated from the fraction with a high boiling point had the effect of relaxing the uterine smooth muscle. Among them, compounds 5 and 6 inhibited the extracellular Ca~(2+) influx and intracellular Ca~(2+) release to relax the uterine smooth muscle. In conclusion, the components with high boiling points and sesquiterpenes are the active components in the essential oil of C. phaeocaulis for treating dysmenorrhea.

Highly polar chemical constituents from whole herb of Scindapsus officinalis

Macroporous resin column chromatography, MCI medium pressure column chromatography, and semi-preparative high performance liquid chromatography were employed to isolate the chemical components from the aqueous extract of the whole herb of Scindapsus officinalis. The structures of the compounds were identified based on the physical and chemical properties and the spectroscopic data. Ten compounds were isolated from the aqueous extract and identified as 3,4-dihydroxyphenylethyl-8-O-[β-D-apiofuranosyl-(1→4)]-β-D-glucopyranoside(1), alternamide B(2), 3,4-dihydroxyphenylethyl-O-β-D-glucopyranoside(3), 1-(4-hydroxy)-phenylethyl-β-D-galactopyranoside(4), 3,4-dihydroxyphenylethyl-8-O-[β-D-apiofuranosyl-(1→2)]-β-D-glucopyranoside(5), hydroxytyrosol-4-O-β-D-glucopyranoside(6), 3,5-dihydroxyphenylethyl-3-O-β-D-glucopyranoside(7), salidroside(8), dihydroisoquinolone(9), and 4-methoxybenzenepropanol-3-O-β-D-glucopyranoside(10). Among them, compound 1 was a new one, and compounds 2-10 were obtained from S. officinalis for the first time. The RAW264.7 cells were exposed to lipopolysaccharide for the mode-ling of inflammation, and the cells were then used to examine anti-inflammatory activities of the compounds. The results showed that compounds 6 and 7 had strong anti-inflammatory activities, while compounds 1, 2, and 5 had moderate anti-inflammatory activities.

In vitro analysis of quercetin-like compounds from mistletoe Dendrophthoe pentandra (L.) Miq as a potential antiviral agent for Newcastle disease

Background Recent evidence suggests that some flavonoid compounds obtained from crude methanol extract of mistletoe leaves (Dendrophthoe pentandra L. Miq), also known as Benalu Duku (BD), have antimicrobial effects. Thus, the plant has the potential to eliminate viruses that may cause outbreaks in chicken farms. This study aimed to prove the in vitro ability of flavonoid compounds, namely quercetin-like compounds (QLCs), to eliminate field viruses, specifically the Newcastle disease virus (NDV). Methods This research was performed in two stages. An in vitro test was used with a post-test of the control groups designed at a significance of 0.05. BD leaves (5 kg) were extracted using a maceration method with methanol and then separated into hexane, chloroform, ethyl acetate, and methanol fractions. The final extracted products were separated using semi-preparative high-performance liquid chromatography (HPLC) to obtain QLCs. The QLCs were identified and compared with quercetin using HPLC, proton and carbon nuclear magnetic resonance spectrometry, Fourier transform infrared spectrophotometry, and ultra-performance liquid chromatography–mass spectrometry. The activity of QLCs was tested in vitro against the NDV at a virulence titer of 10−5 Tissue Culture Infectious Dose 50% (TCID50) in chicken kidney cell culture. Results Solutions of 0.05% (w/v) QLCs were discovered to have antiviral activity against NDVs, with an average cytopathogenic effect antigenicity at a 10−5 dilution (p<0.05). Conclusions QLCs from flavonoids from the leaves of BD have in vitro antiviral bioactivity against NDV at a virulence titer of 10-5 Tissue Culture Infectious Dose 50% (TCID50) in chicken kidney cell culture. QLCs may have the potential to be developed as medicinal compounds for the treatment of other human or animal viral infections.

A new sesquiterpenoid from Lindera aggregata

The chemical composition of the aqueous part of the extract from Lindera aggregata was studied, which was separated and purified by the macroporous resin column chromatography, MCI medium pressure column chromatography, semi-preparative high-performance liquid phase and other methods. The structures of the compounds were identified according to physical and chemical properties and spectroscopic data. Thirteen compounds were isolated and identified from the aqueous extracts, which were identified as(1S,3R,5R,6R,8S,10S)-epi-lindenanolide H(1), tachioside(2), lindenanolide H(3), leonuriside A(4), 3,4-dihydroxyphenyl ethyl β-D-glucopyranoside(5), 3,4,5-trimethoxyphenol-1-O-6-α-L-rhamnose-(1→6)-O-β-D-glucoside(6), 5-hydroxymethylfurfural(7),(+)-lyoniresin-4-yl-β-D-glucopyranoside(8), lyoniside(9), norboldine(10), norisopordine(11), boldine(12), reticuline(13). Among them, compound 1 was a new one, and compounds 2, 5, 6, 8, 9 were obtained from L. aggregata for the first time. The inflammatory model was induced by lipopolysaccharide(LPS) in the RAW264.7 cells. The results showed that compounds 1, 8, 10 and 12 had significant anti-inflammatory activity.

Efficient and fast screening and separation based on computer-aided screening and complex chromatography methods for lipoxygenase inhibitors from Ganoderma lucidum.

Accurate screening and targeted preparative isolation of active substances from natural medicines have long been technical challenges in natural medicine research. This study outlines a new approach for improving the efficiency of natural product preparation, focusing on the rapid and accurate screening of potential active ingredients in Ganoderma lucidum and efficient preparation of lipoxidase inhibitors, with the aim of providing new ideas for the treatment of Alzheimer's disease with G.lucidum. The medicinal plant G.lucidum was selected through ultrafiltration coupled with liquid chromatography and mass spectrometry (UF-LC-MS) and computer-assisted screening for lipoxygenase (LOX) inhibitors. In addition, the inhibitory effect of the active compounds on LOX was studied using enzymatic reaction kinetics, and the underlying mechanism is discussed. Finally, based on the earlier activity screening guidelines, the identified ligands were isolated and purified through complex chromatography (high-speed countercurrent chromatography and semi-preparative high-performance liquid chromatography). Five active ingredients, ganoderic acids A, B, C2, D2, and F, were identified and isolated from G.lucidum. We improved the efficiency and purity of active compound preparation using virtual computer screening and enzyme inhibition assays combined with complex chromatography. The innovative methods of UF-LC-MS, computer-aided screening, and complex chromatography provide powerful tools for screening and separating LOX inhibitors from complex matrices and provide a favourable platform for the large-scale production of bioactive substances and nutrients.

Microwave-Assisted Rearrangement of Costunolide Catalyzed by Palladium(II)

The structure of costunolide was modified before conducting the Cope rearrangement under thermal conditions. This modification was undertaken to block the highly reactive Michael acceptor α-methylene-γ-lactone, thus preventing side reactions at high temperatures. In this work, the reaction was performed under heating or microwave irradiation using costunolide, not its modified version. Rates of Cope reactions catalyzed by palladium(II) assisted by microwave were substantially enhanced. The rearrangements of costunolide to elemanolide, eudesmanolides, and germacranolide were catalyzed by palladium acetate, bis(benzonitrile)palladium dichloride, and a mixture of both organometallics. Rates of microwave promoted rearrangements of costunolide were six times faster than the reactions assisted by heating. The best success rate for elemanolide (7) was obtained using a mixture of Pd(OAc)2 and (NCPh)2PdCl2. In this case, compound 7 was obtained in a yield of 34%, while the other sesquiterpene lactones were formed only in trace amounts. The reaction products were isolated using semi-preparative high performance liquid chromatography and further purified through sequential analytical high performance liquid chromatography. Bioactivity profiles that used etiolated wheat coleoptiles were conducted for compounds 6, 7, and 9. The tested compounds presented very high phytotoxicity, with inhibition up to 97%.

Antimicrobial Cyclic Dipeptides from Japanese Quail (Coturnix japonica) Eggs Supplemented with Probiotic Lactobacillus plantarum.

Fifteen cyclic dipeptides (CDPs) containing proline, one cyclo(Phe-Ala) without proline, and a non-peptidyl DL-3-phenyllactic acid were previously identified in the culture filtrates of Lactobacillus plantarum LBP-K10, an isolate from kimchi. In this study, we used Japanese quail (Coturnix japonica) eggs to examine the effects of probiotic supplementation on the antimicrobial CDPs extracted from quail eggs (QE). Eggshell-free QE were obtained from two distinct groups of quails. The first group (K10N) comprised eggs from unsupplemented quails. The second group (K10S) comprised eggs from quails supplemented with Lb. plantarum LBP-K10. The QE samples were extracted using methylene chloride through a liquid-liquid extraction process. The resulting extract was fractionated into 16 parts using semi-preparative high-performance liquid chromatography. Two fractions, Q6 and Q9, were isolated from K10S and identified as cis-cyclo(L-Ser-L-Pro) and cis-cyclo(L-Leu-L-Pro). The Q9 fraction, containing cis-cyclo(L-Leu-L-Pro), has shown significant inhibitory properties against the proliferation of highly pathogenic multidrug-resistant bacteria, as well as human-specific and phytopathogenic fungi. Some of the ten combinations between the remaining fourteen unidentified fractions and two fractions, Q6 and Q9, containing cis-cyclo(L-Ser-L-Pro) and cis-cyclo(L-Leu-L-Pro) respectively, demonstrated a significant increase in activity against multidrug-resistant bacteria only when combined with Q9. The activity was 7.17 times higher compared to a single cis-cyclo(L-Leu-L-Pro). This study presents new findings on the efficacy of proline-containing CDPs in avian eggs. These CDPs provide antimicrobial properties when specific probiotics are supplemented.

Characterization and Isolation of Piperamides from Piper nigrum Cultivated in Costa Rica

The piperamides profile of Piper nigrum cultivated in Costa Rica was studied using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight high-resolution mass spectrometry (UPLC-ESI-QTOF-HRMS) on enriched-piperamides extracts. A total of 31 different piperamides were identified, 24 of them with a methylenedioxyphenyl moiety, including piperine and nine other compounds with the characteristic piperidine ring, as well as guineensine, retrofractamide B, and eight other piperamides with an N-isobutyl group. In addition, piperyline and two other compounds with a pyrrolidine ring, as well as piperflaviflorine B, holding a N-2-methylbutyl chain, were characterized. In turn, pellitorine and six other piperamides exhibiting a long olefinic chain instead of the methylenedioxyphenyl group were also tentatively identified. In addition, quantification was performed using UPLC coupled with a diode array detector (UPLC-DAD), with 15 piperamides being quantified, including piperine, piperyline, piperanine, and piperloguminine with values within the range of previous reports, while results obtained for guineensine (276.5–421.0 mg/100 g dry material) and pellitorine (414.4–725.0 mg/100 g dry material) were higher than those reported in the literature. Additionally, preparative and semi-preparative high-performance liquid chromatography (HPLC) separations allowed to isolate, besides piperine, four other piperamides, which were identified through HRMS, 1H and 13C nuclear magnetic resonance (NMR). These included retrofractamide B, guineensine, pellitorine, and (2E,4E,12Z)-N-isobutyl-octadeca-2,4,12-trienamide, with yields of 134.0 mg/100 g dry material, 209.7 mg/100 g dry material, 361.8 mg/100 g dry material and 467.0 mg/100 g dry material, respectively, with all these values higher than those reported in previous studies in the literature. The findings constitute the first report of such a number and diversity of compounds in P. nigrum cultivated in Costa Rica.

Two new sesquiterpenes in Qi-nan Aquilariae Lignum Resinatum

This study aimed to investigate the chemical constituents of supercritical extract from Qi-nan Aquilariae Lignum Resinatum by silica gel column chromatography, thin-layer chromatography, and semi-preparative high-performance liquid chromatography. One new elemane-type and one new eudesmane-type sesquiterpene compounds were isolated from the extract, and their structures were identified by MS, UV, IR, NMR, and ECD spectroscopic techniques, and named aquqinanol C(1) and aquqinanol D(2). Both compounds are novel compounds. The neuroprotective effect of the compounds on CORT-induced PC12 cell damage was determined in vitro. The results showed that compounds 1 and 2 exhibited a certain protective effect against CORT-induced damage in PC12 cells.

In vitro analysis of quercetin-like compounds from mistletoe Dendrophthoe pentandra (L.) Miq as a potential antiviral agent for Newcastle disease

Background Recent evidence suggests that some flavonoid compounds obtained from crude methanol extract of mistletoe leaves (Dendrophthoe pentandra L. Miq), also known as Benalu Duku (BD), have antimicrobial effects. Thus, the plant has the potential to eliminate viruses that may cause outbreaks in chicken farms. This study aimed to prove the in vitro ability of flavonoid compounds, namely quercetin-like compounds (QLCs), to eliminate field viruses, specifically the Newcastle disease virus (NDV). Methods This research was performed in two stages. An in vitro test was used with a post-test of the control groups designed at a significance of 0.05. BD leaves (5 kg) were extracted using a maceration method with methanol and then separated into hexane, chloroform, ethyl acetate, and methanol fractions. The final extracted products were separated using semi-preparative high-performance liquid chromatography (HPLC) to obtain QLCs. The QLCs were identified and compared with quercetin using HPLC, proton and carbon nuclear magnetic resonance spectrometry, Fourier transform infrared spectrophotometry, and ultra-performance liquid chromatography–mass spectrometry. The activity of QLCs was tested in vitro against the NDV at a virulence titer of 10−5 Tissue Culture Infectious Dose 50% (TCID50) in chicken kidney cell culture. Results Solutions of 0.05% (w/v) QLCs were discovered to have antiviral activity against NDVs, with an average cytopathogenic effect antigenicity at a 10−5 dilution (p<0.05). Conclusions QLCs from flavonoids from the leaves of BD have in vitro antiviral bioactivity against NDV at a virulence titer of 10-5 Tissue Culture Infectious Dose 50% (TCID50) in chicken kidney cell culture. QLCs may have the potential to be developed as medicinal compounds for the treatment of other human or animal viral infections.

The antifungal substance from Bacillus velezensis B-3 improved the malt quality against premature yeast flocculation induced by Fusarium graminearum infection.

Malt produced from barley contaminated with Fusarium graminearum can cause premature yeast flocculation (PYF) in beer fermentation, which ultimately affects the production efficiency and flavor quality of beer. In this study, a strain of Bacillus velezensis B-3 that was isolated from soil displayed strong antifungal activity against F. graminearum. The antifungal substances were extracted and separated by ammonium sulfate fractional precipitation and semipreparative high-performance liquid chromatography to obtain fraction VI with the strongest antifungal activity. Ultra-performance liquid chromatography-quadrupole-time-of-flight-mass spectrometry was used to identify that the fraction contained lipopeptides such as iturin A, surfactant B, and surfactant C. The minimum inhibitory concentration of the fraction was 0.2mg/mL, and confocal laser scanning microscopy showed that the morphology of F. graminearum hyphae was obviously abnormal, with most of them were dead. Antifungal fraction VI could inhibit the growth of F. graminearum and avoid the production of PYF factor during malting but did not affect other qualities of malt. Therefore, the development of antimicrobial agents against Fusarium provides an effective potential strategy to control the production of PYF factors for malt-manufacturing enterprises. PRACTICAL APPLICATION: Antifungal fraction VI could inhibit the growth of F. graminearum and the formation of DON during malting but did not affect other qualities of malt. The levels of soluble nitrogen, free amino nitrogen, and color experienced a substantial reduction compared to the malt infected by F. graminearum. The PYF phenomenon was significantly improved, the number of suspended yeast cells and the degree of fermentation were increased, and the level of residual extract in the wort was low, close to that of control malt.