Natural Product Extracts Research Articles

α-Glucosidase inhibitors from the bark of Mangifera mekongensis.

BackgroundMangifera mekongensis (Anacardiaceae) is cultivated for its edible fruit and has been used in traditional Vietnamese medicine for its anti-aging properties and for treating diabetes, vermifuge, and dysentery. As part of a search for biologically active compounds with reduction of the rate of glucose absorption, a screening has been initiated to evaluate natural product extracts for the inhibition of enzyme α-glucosidase. A n-hexane extract of the bark of M. mekongensis showed strong α-glucosidase inhibitory activity with IC50 value of 1.71 µg/mL. Thus, the constituents of this plant were examined.ResultsTwo new steroids named mekongsterol A (1) and mekongsterol B (2), were isolated from the n-hexane extract of the bark of M. mekongensis (Anacardiaceae), together with seven known compounds (3–9). Their chemical structures were elucidated on the basis of spectroscopic data. All compounds possessed significant α-glucosidase inhibitory activity in a concentration-dependent manner, except for 3 and 4. Compounds 1, 2, 5–9 showed more potent inhibitory activity, with IC50 values ranging from 1.2 to 112.0 µM, than that of a positive control acarbose (IC50, 214.5 µM).ConclusionsThese results suggested that the traditional use of the bark of M. mekongensis for the treatment of diabetes diseases in Vietnam may be attributable to the α-glucosidase inhibitory activity of its steroid and cycloartane constituents.Electronic supplementary materialThe online version of this article (doi:10.1186/s13065-016-0193-9) contains supplementary material, which is available to authorized users.

Abstract 3102: Identify potential therapeutic drugs on head and neck cancer through systemic bioinformatics approach

Abstract Head and neck cancer (HNC) is one of the ten most frequent cancers worldwide. In Taiwan, with the the rising incidence in the past decade, HNC has become the fourth male malignant disease since year 2009. The standard therapy methods of HNC are surgery, radiation, chemotherapy or the combination of these modalities. Overall 5-year survival rate in patients with HNC is one of the lowest among common malignant neoplasms treatment of this disease and has not significantly improved over the past decades. To improve the identification of potential therapeutic drug process, integrating the signature of diseases, genes, and drugs was analyzed through bioinformatics method to find therapeutic candidates through comparison of gene signatures between disease and drug treatment. Here, we integrated HNC gene signatures (including 202 oral squamous carcinomas and 69 normal control species) and connectivity map drug database, and after querying, the drug shown with negative correlation may serve as therapeutic candidates to reverse oral cancer signature. Four potential small molecules with antitumor properties including natural product extracts or clinical therapeutic drugs in other diseases were identified. One of the natural product extracts was found it inhibited cell migration ability, cell invasion capacity and cancer stem cell sphere formation capability. Furthermore, the compound was demonstrated that tit regulated the epithelial-mesenchymal transition markers, suppressed the expression of stemness-related transcription factors (SOX2, Oct-4, and NANOG), and increased the expression of cell differentiation marker (CK18). The compound can also increase cell sensitivity to chemodrug- and radiation treatment then then suppress tumor growth in vitro and in vivo. Taking together, our study demonstrates a novel approach in drug development, by a bioinformatics method to effectively identify potential compounds for head and neck cancer therapy. Citation Format: Chen Yin-Ju, Jeng-Fong Chiou. Identify potential therapeutic drugs on head and neck cancer through systemic bioinformatics approach. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3102.

High-Throughput Screening Platform for the Discovery of New Immunomodulator Molecules from Natural Product Extract Libraries

It is widely accepted that central nervous system inflammation and systemic inflammation play a significant role in the progression of chronic neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease, neurotropic viral infections, stroke, paraneoplastic disorders, traumatic brain injury, and multiple sclerosis. Therefore, it seems reasonable to propose that the use of anti-inflammatory drugs might diminish the cumulative effects of inflammation. Indeed, some epidemiological studies suggest that sustained use of anti-inflammatory drugs may prevent or slow down the progression of neurodegenerative diseases. However, the anti-inflammatory drugs and biologics used clinically have the disadvantage of causing side effects and a high cost of treatment. Alternatively, natural products offer great potential for the identification and development of bioactive lead compounds into drugs for treating inflammatory diseases with an improved safety profile. In this work, we present a validated high-throughput screening approach in 96-well plate format for the discovery of new molecules with anti-inflammatory/immunomodulatory activity. The in vitro models are based on the quantitation of nitrite levels in RAW264.7 murine macrophages and interleukin-8 in Caco-2 cells. We have used this platform in a pilot project to screen a subset of 5976 noncytotoxic crude microbial extracts from the MEDINA microbial natural product collection. To our knowledge, this is the first report on an high-throughput screening of microbial natural product extracts for the discovery of immunomodulators.

Process design for integration of extraction, purification and formulation with alternative solvent concepts

Methods of Green Chemistry are in the meantime established in process design for extraction of natural products [1]. Moreover, natural products do have the inherent societal benefit of being a priori bio-degradable and therefore do not cause any additional waste-water and recycling problems in hospitals, cities and municipalities or environmental enrichment [2]. Nevertheless, those inherent benefits could be easily compromised if they are not combined with the design and operation of fully integrated processes in manufacturing. One isolated action of Green Chemistry is not sufficient to gain the entrepreneurial balance of economy and ecology with competitive manufacturing, new marketable products, and sustainability. While any process modification could be implemented in substituting simply one existing step, a fully integrated new process needs to be set up to exceed the existing benchmark or best practice and to be transferred into manufacturing. Finding alternative solvents and enhancing mass transfer in extraction need to be integrated. This integration into a complete process from extraction over purification to formulation, considering recycling at all steps, is a complex task which could not be fulfilled on a purely experimental basis. The efforts would be too high and costly. Therefore, the paper reviews the existing status shortly and exemplifies based on a case study, choosing 10-deacetylbaccatin III as a typical example, a theoretical approach in thermodynamics and process modeling, and how they can contribute to an alternative process design. Still, these steps in conceptual process design and basic engineering seem to be the major challenge in industrial acceptance of alternative ideas. The authors have described the transfer into innovative manufacturing concepts already elsewhere [1], [2], [3].

Screening and Biological Effects of Marine Pyrroloiminoquinone Alkaloids: Potential Inhibitors of the HIF-1α/p300 Interaction.

Inhibition of the hypoxia-inducible factor 1α (HIF-1α) pathway by disrupting its association with the transcriptional coactivator p300 inhibits angiogenesis and tumor development. Development of HIF-1α/p300 inhibitors has been hampered by preclinical toxicity; therefore, we aimed to identify novel HIF-1α/p300 inhibitors. Using a cell-free assay designed to test compounds that block HIF-1α/p300 binding, 170 298 crude natural product extracts and prefractionated samples were screened, identifying 25 active extracts. One of these extracts, originating from the marine sponge Latrunculia sp., afforded six pyrroloiminoquinone alkaloids that were identified as positive hits (IC50 values: 1-35 μM). Luciferase assays confirmed inhibition of HIF-1α transcriptional activity by discorhabdin B (1) and its dimer (2), 3-dihydrodiscorhabdin C (3), makaluvamine F (5), discorhabdin H (8), discorhabdin L (9), and discorhabdin W (11) in HCT 116 colon cancer cells (0.1-10 μM, p < 0.05). Except for 11, all of these compounds also reduced HIF-1α transcriptional activity in LNCaP prostate cancer cells (0.1-10 μM, p < 0.05). These effects occurred at noncytotoxic concentrations (<50% cell death) under hypoxic conditions. At the downstream HIF-1α target level, compound 8 (0.5 μM) significantly decreased VEGF secretion in LNCaP cells (p < 0.05). In COLO 205 colon cancer cells no activity was shown in the luciferase or cytotoxicity assays. Pyrroloiminoquinone alkaloids are a novel class of HIF-1α inhibitors, which interrupt the protein-protein interaction between HIF-1α and p300 and consequently reduce HIF-related transcription.

Supercritical extracts of forest fuels in Great Xing’an Mountains

Extracts are important components of fuels. Fatty-extracts with high heating value (HV) are hypothesized by researchers as positively related to the HV of fuels. The Soxhlet extractor is typically used to extract fatty-extracts but it has shortcomings, including long processing time (8–10 h) and the requirement for large amounts of organic solvent. Supercritical extraction is an alternate and useful technique for extraction of natural products. However, published studies rarely discuss the relationship between extracts and HV. In this study, we assessed the supercritical extracts (SuE) of forest fuels in the Great Xing’an Mountains. Our results indicated that the optimum conditions for extraction of SuEs were 40–60 mesh, 40–50 MPa, 45 °C, 80 min and a CO2 flow rate of 1.5–2.0 dm3/min. The Soxhlet extracts contents and the SuE contents were all related to HV. However, R 2 of the coniferous samples (0.8499) and needle samples (0.9722) demonstrated that the correlation between HV and the SuE content was closer. We conclude that supercritical fatty-extracts provide a useful index of the HV of fuels, especially coniferous fuels. SuE data can be used in fire management, for example to estimate the rate of fire spread or fire intensity.

Enhancing natural product extraction and mass transfer using selective microwave heating

This study uses a combination of empirical observations and an analysis of mass transfer behaviour to yield new insights into the mechanism of microwave assisted extraction. Enhancements in extraction rate and yield were observed experimentally compared with conventional extraction at temperatures in excess of 50°C, however at lower temperatures there was no observable difference between the two processes. A step-change in extract yield between microwave and conventional processes was shown to be caused by selective heating. A temperature gradient of the order of 1°C is sufficient to reduce the water chemical potential within the cell structure, which changes the osmotic potential such that internal cell pressures can increase to the point where disruption occurs. This paper demonstrates the need to operate microwave extraction processes at a temperature that enables selective heating, and a newly-proposed mass transfer phenomenon that could have wider positive implications for extraction and leaching processes.

Semi‐Bionic Extraction of Effective Ingredient from Fishbone by High Intensity Pulsed Electric Fields

AbstractSemi‐bionic extraction method and high intensity pulsed electric fields (PEF) were combined to rapidly extract effective ingredients (calcium, chondroitin sulfate and collagen) from fishbone. In order to simplify the analytical process, comprehensive index formula was determined by principal component analysis. Based on the principle of bionics, the optimal fluid pHs in human stomach, small intestine and large intestine are 2.0, 7.5 and 8.3. The simulated pHs were 2.0, 7.5 and 8.3, respectively, and variation of PEF parameters and the comprehensive evaluation index were determined by single factor experiments. Too low or too high liquid‐material ratio and electric field strength were not conducive to the comprehensive evaluation index Y. The value of Y increased with the increase of pulse number. The maximum contents of calcium, chondroitin sulfate and collagen in the extract were obtained simultaneously by response surface methodology (RSM), that is, 19.8, 39.268 and 3.875 mg/mL, respectively The optimum condition is as the following: liquid‐material ratio 11, electric field strength 22.79 kV/cm and pulse number 9.Practical ApplicationsSBE and PEF technique were combined to analyze the effective ingredients in fishbone. The prepared fishbone hydrolysate can be processed into multi‐active and high‐added‐value compound products suitable for absorption and utilization by the digestive tract. This paper provides a new technique for comprehensive utilization of fishbone and fishbone waste, serves as a new clue for processing and extraction of natural products and provides a basis for promotion of SBE and PEF.

Production of an antioxidative peptide from hairy basil seed waste by a recombinant Escherichia coli.

To circumvent the time-consuming and costly problems associated with natural product extraction, a potential antioxidative peptide selected from hairy basil waste after oil extraction was produced by recombinant DNA technology. Because the target peptide is short, the recombinant peptide containing seven repeats of the target sequence, QTFQYSRGWTN, and the DNA fragment coding this sequence was cloned into the pQE-30 Xa expression vector and transformed into Escherichia coli. After 6h of recombinant peptide expression in E. coli, the target peptide was purified by Ni(2+) affinity chromatography and gel extraction. The expected 15kDa recombinant target peptide construct was verified by modified dot blot analysis. Compared with the chemically synthesized peptide, the recombinant peptide revealed significantly higher antioxidant activities (p<0.05), as determined by DPPH and ABTS radical scavenging assays, and in vitro DNA damage induced by hydroxyl radicals. This approach provides an alternative to produce an antioxidative peptide that provides a potential scaffold for the further development of antioxidative peptides for industrial applications.

Anti-Mycobacterium tuberculosis Activity of Calophyllum brasiliense Extracts Obtained by Supercritical Fluid Extraction and Conventional Techniques

The conventional techniques used to extract natural products have many disadvantages, and alternative methods have been used, such as supercritical fluid extraction (SFE-CO2). We compared the anti-Mycobacterium tuberculosis activity and cytotoxicity of extracts and major pure compounds were obtained from the leaves of Calophyllum brasiliense by SFE-CO2, maceration and Soxhlet. Anti-M tuberculosis activity was evaluated by resazurin microtiter assay plate and cytotoxicity assay was performed using 3-(4,5-dimethyl thiazol-2-yl)-2,5-diphenyl tetrazolium bromide. The (-) mammea A/BB, (-) mammea B/BB, mammea B/BB cyclo D, ponnalide, mammea A/BA cyclo D, and amentoflavone were identified as the majority compounds. SFE-CO2, especially at 313 K and 10.92 MPa showed better yield for (-) mammea A/BB. Anti-M. tuberculosis activity (62.5 μg/mL) and cytotoxicity (Selectivity Index = 0.320-0.576) were similar for the three extracts. Mammea B/BB cyclo D had a minimum inhibitory concentration (MIC) of 125 μg/mL, and ponnalide and mammea A/BA cyclo D had MICs > 250 μg/mL. The pure compounds isolated showed low Selectivity Index (< 0.09). SFE-CO2 may be more promising than conventional methods for the extraction of compound (-) mammea A/BB, which presented the best anti-M. tuberculosis activity in our previous study. This is important for current industrial requirements to obtain extracts from medicinal plants using clean technologies.

Natural products extract effect on bone integration around orthodontic micro-implant: An experimental study

Background and objective: Bone integration around orthodontic implant is a matter of concern for their stability. This study was conducted to estimate calcium and phosphorous level in after insertion of orthodontic implant. Methods: Twenty five white mature male rabbits, classified into 5 groups: one control and four experimental, with five rabbits for each group were used. Fifty orthodontic implants were used, 2 micro-implant for each tibia. Four different natural products extract were used in this study that included Curcumin 15mg/kg, Nigella Sativa oil 0.25 ml/kg, Cissus Quadrangularis 500mg/kg and Virgin Coconut oil 1 ml/kg. Each product was given to certain experimental group started from the day of implant insertion for four weeks healing period. The biochemistry evaluation was conducted involving calcium and phosphorus level in serum. Results: Significant difference in serum calcium levels were detected between Curcumin, Nigella Sativa oil from side and control group on the other side. Conclusion: Systemic Curcumin and Nigella sativa oil may be used for possibly enhancing bone response around orthodontic implant as reflected by lower serum calcium level as compared to control group.

TLC Screening and Evaluation of Antioxidant, Antibacterial Activity of Onopordon Macrocephalum by Bioautography Method

TLC screening and Evaluation of antioxidant, antibacterial activity of Onopordon macrocephalum by bioautography methodOnopordon known as scotch thistle is a medicinal plant of the Asteraceae family that is widely distributed in Europe and Asia, also it has many valuable medicinal properties as hypotensive and antitumor. Thin layer chromatography (TLC) is wildly used in natural product extract analysis as a finger print which can be used for identification and quality control of medicinal preparations. Performing Thin-layer chromatography TLC tests on the plant show the presence of flavonoids, coumarins and bitter principles. Planar chromatographic analysis hyphenated with the biological detection method is known as bioautography which is an effective and inexpensive technique for the phytochemical analysis of plant extracts. Thin-layer chromatography-direct bioautography links separation on the adsorbent layer with biological tests performed directly on it in order to identify antimicrobial and antioxidant activities. Bioautography revealed that Staphylococcus aureus was inhibited by most of the flavonoids separated on the TLC plates. Similarly, growth of the Bacillus cereus was also inhibited by one flavonoid band on TLC. Antioxidant bioautography shows the strong antioxidant activity of one flavonoid band, whereas no activity detected of bitter principles. Bioautography showed that the antimicrobial and antioxidant activity was probably due to flavonoids.

Isolation, analytical measurements, and cell line studies of the iron–bryostatin-1 complex

Bryostatin-1 is a marine natural product that has demonstrated medicinal activity in pre-clinical and clinical trials for the treatment of cancer, Alzheimer’s disease, effects of stroke, and HIV. In this study, iron–bryostatin-1 was obtained using a pharmaceutical aquaculture technique developed by our lab that cultivates marine bacteria for marine natural product extraction. Analytical measurements 1H and 13C NMR, mass spectrometry, and flame atomic absorption were utilized to confirm the presence of an iron–bryostatin-1 complex. The iron–bryostatin-1 complex produced was then tested against the National Cancer Institute’s 60 cell line panel. Adding iron to bryostatin-1 lowered the anti-cancer efficacy of the compound.

Infrared Irradiation: Toward Green Chemistry, a Review.

This review provides a comprehensive overview of where infrared irradiation has been employed, mainly as regards activating green mode for natural products extractions, as well as to favor a reaction, highlighting its actual importance. It is also underlined that infrared irradiation heating has been around for a long time; however, only in the last eighteen years have many of its advantages been applied to satisfy a wide range of chemical processes, natural products extractions, and for the promotion of many kinds of reactions. In addition, it is brought to light that near infrared irradiation is more efficient than middle and far infrared irradiations, being easily controllable and with the quality of a fast responding heat source. Thus, the main objective of this review is to offer infrared irradiation as an alternative clean energy source to activate reactions, in addition to favor the selective extraction of natural products, all of which is within the Green Chemistry protocol. Some recent results from our laboratory are also included.

Fast environment-friendly ball mill-assisted deep eutectic solvent-based extraction of natural products

A fast environment-friendly extraction method, ball mill-assisted deep eutectic solvent-based extraction, was used for the extraction of natural products from plants. In this study, tanshinones were selected as target compounds to evaluate the efficiency of the developed extraction method. Under the optimized experimental conditions, cryptotanshinone (0.176mg/g), tanshinone I (0.181mg/g), and tanshinone II A (0.421mg/g) were extracted from Salvia miltiorrhiza Bunge, and the developed method was found to be greener, more efficient, and faster than conventional, environmentally harmful extraction methods such as methanol-based ultrasound-assisted extraction and heat reflux extraction. The analytical performances including recovery, reproducibility (RSD, n=5), correlation of determination (r2), and the limit of detection, with the ranges of 96.1–103.9%, 1.6–1.9%, 0.9973–0.9984, and 5–8ng/mL, were respectively obtained. Application of ball mill-assisted deep eutectic solvent-based extraction may fundamentally shape the future development of extraction methods.

Comprehensive Evaluation of Deep Eutectic Solvents in Extraction of Bioactive Natural Products

Deep eutectic solvents (DESs) are emerging as green and sustainable solvents for efficient extraction of bioactive compounds or drugs. This work aimed to comprehensively evaluate the potential and effectiveness of DESs for extraction of different types of natural compounds from biomass. Five Chinese herbal medicines including Berberidis Radix, Epimedii Folium, Notoginseng Radix et Rhizoma, Rhei Rhizoma et Radix, and Salviae Miltiorrhizae Radix et Rhizoma were selected to assess the efficiency of DESs on extraction of alkaloids, flavonoids, saponins, anthraquinones, and phenolic acids, respectively. Totally 43 types of choline chloride-, betaine-, and l-proline-based DESs with different polarity, viscosity, composition, and solubilization abilities were tailored to test their extraction efficiency, and the operation conditions were statistically optimized using response surface methodology to produce the most efficient process. In this work, DES solvents were first introduced to extract alkaloids and anthr...

Blind column selection protocol for two-dimensional high performance liquid chromatography

The selection of two orthogonal columns for two-dimensional high performance liquid chromatography (LC×LC) separation of natural product extracts can be a labour intensive and time consuming process and in many cases is an entirely trial-and-error approach. This paper introduces a blind optimisation method for column selection of a black box of constituent components. A data processing pipeline, created in the open source application OpenMS®, was developed to map the components within the mixture of equal mass across a library of HPLC columns; LC×LC separation space utilisation was compared by measuring the fractional surface coverage, fcoverage. It was found that for a test mixture from an opium poppy (Papaver somniferum) extract, the combination of diphenyl and C18 stationary phases provided a predicted fcoverage of 0.48 and was matched with an actual usage of 0.43. OpenMS®, in conjunction with algorithms designed in house, have allowed for a significantly quicker selection of two orthogonal columns, which have been optimised for a LC×LC separation of crude extractions of plant material.

Purification Of Natural Product Extracts Using Integrated Flash And Preparative Chromatography

Isolation and purification of active components from natural origins is a challenging process requiring multiple steps and often large amounts of organic solvent. The diversity of compounds present in an extract is large and adequate purification can require different chromatographic techniques for effective isolation. A further complication is that natural product extracts may contain critical components that are both chromophoric and non-chromophoric. Identifying non-chromophoric compounds in complex mixtures can be difficult. Traditional ultraviolet (UV) detection fails to detect targets and impurities that are present at low levels or lack chromophores. Evaporative light scattering detection (ELSD) provides advantages over spectroscopic detectors for detecting compounds that are deficient in a UV-absorbing chromophore or fluorophore.

Small Scale Purification Of Constituents From Complex Natural Product Extracts Using Sub-2 µm Chromatography

Extracts from natural product samples can be complex and often contain a large number of diverse compounds. Increased separation performance of sub-2-µm particle column technology along with low dispersion instrumentation provides a tool that produces sharp, narrow, and more concentrated peaks. When there is a need to collect these narrow peaks from complex mixtures, traditional fraction collection instrumentation designed for preparative HPLC does not provide an adequate solution, primarily due to peak broadening through collection valves and tubing. Extracts from three natural product samples (Rosemary, Schisandra Berry, and Angelica Root) were analyzed using sub-2-µm chromatography and potential peaks of interest were identified and isolated using a fraction collector specifically designed to collect peaks generated from sub-2-µm chromatography. Collected fractions were then analyzed to determine purity.

Industrial Feasibility of Natural Products Extraction with Microwave Technology

AbstractThe industrial extraction of natural products based on microwave irradiation of plant material and volumetric heating is now an industrial reality. Besides significant reduction in waste generation, manufacturing biomass extracts via microwave‐assisted extraction (MAE) leads to such technical, economic, and environmental benefits whose entity, we argue, will end the distillation era of solid‐liquid extraction using hydrocarbon solvents.