Natascha Techen- Ph.D.
- Research Assistant at University of Mississippi
Natascha Techen
- Ph.D.
- Research Assistant at University of Mississippi
About
155
Publications
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Introduction
Current institution
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October 2003 - present
Publications
Publications (155)
Edwardsiella ictaluri and Flavobacterium covae are two bacteria species that cause diseases in farm‐raised channel catfish ( Ictalurus punctatus ) that cause heavy economic damage to the aquaculture industry, particularly to the channel catfish farming. In search for environmentally benign antibacterial compounds active against E. ictaluri and F. c...
Characterization of botanical extracts by mass spectrometry-based metabolomics analysis helps in determining the phytochemical composition that underlies their bioactivity and potential health benefits, while also supporting reproducibility of effects in clinical trials. The quantification of seven withanolides in Withania somnifera using three mas...
Introduction
Centella asiatica (CA) is known in Ayurvedic medicine as a rejuvenating herb with particular benefits in the nervous system. Two groups of specialized metabolites found in CA and purported to contribute to its beneficial effects are triterpenes (TTs) and caffeoylquinic acids (CQAs). In order to evaluate the role and interactions of TTs...
A bacterium growing on infected leaves of Hydrocotyle umbellata, commonly known as dollarweed, was isolated and identified as Pantoea ananatis. An ethyl acetate extract of tryptic soy broth (TSB) liquid culture filtrate of the bacterium was subjected to silica gel chromatography to isolate bioactive molecules. Indole was isolated as the major compo...
Morphological similarity within species makes the identification and authentication of Salvia species challenging especially in dietary supplements that contain processed root or leaf powder of different sage species. In the present study, the species discriminatory power of two potential DNA barcode regions from the nuclear genome was evaluated in...
Salvia mellifera (black sage) and Salvia apiana (white sage) are known for complex introgressive hybridization. Morphological variations between these two Salvia species and their varieties present overlapping characters that may cause confusion in identifying the genuine species in nature. Since these plants may be candidates for investigation of...
In the realm of applied phycology, algal physiology, and biochemistry publications, the absence of proper identification and documentation of microalgae is a common concern. This poses a significant challenge for non-specialists who struggle to identify numerous eukaryotic microalgae. However, a promising solution lies in employing an appropriate D...
The Natural Herbal Products industry uses botanicals or herbs as raw materials for production of herbal products or dietary supplements. Recently, the demand for natural herbal products has increased tremendously and this has led to adulteration and to counterfeit herbal products. The present chapter deals with currently used molecular methods from...
REVIEW Abstract Microalgae, as a diverse photosynthetic group of microorganisms with substantial ecological significance, have enormous potential for use in the food, medicine, and energy industries. However, current limitations in cost-effective production restrict their ubiquitous use. The purpose of this comprehensive mini-review is to investiga...
The French Lentil & Leek Crumbles frozen food product was recently recalled due to reports of gastrointestinal issues. So far, 393 adverse illness complaints and 133 hospitalizations have been reported from consumption of this food, and the tara (Tara spinosa) protein flour ingredient is hypothesized to be responsible. A multipronged approach resul...
Morphological similarity within species makes the identification and authentication of Salvia species challenging, especially in dietary supplements that contain processed root or leaf powder of different sage species. In the present study, the species discriminatory power of 2 potential DNA barcode regions from the nuclear genome was evaluated in...
The presence of bio-macromolecules as major ingredients is a primary factor in marketing many biologically derived macromolecular supplements. Workflows for analyzing these supplements for quality assurance, adulteration, and other supply-chain difficulties must include a qualitative assessment of small-molecule and macromolecular components; howev...
The metabolic pathways in the apicoplast organelle of Plasmodium parasites are similar to those in plastids in plant cells and are suitable targets for malaria drug discovery. Some phytotoxins released by plant pathogenic fungi have been known to target metabolic pathways of the plastid; thus, they may also serve as potential antimalarial drug lead...
Bioassay-guided fractionation of an EtOAc extract of the broth of the endophytic fungus Nemania sp. UM10M (Xylariaceae) isolated from a diseased Torreya taxifolia leaf afforded three known cytochalasins, 19,20-epoxycytochalasins C (1) and D (2), and 18-deoxy-19,20-epoxy-cytochalasin C (3). All three compounds showed potent in vitro antiplasmodial a...
This paper provides a comparative account of the essential oil chemical composition and biological activities of five Brazilian species of Baccharis (Asteraceae), namely B. microdonta, B. pauciflosculosa, B. punctulata, B. reticularioides, and B. sphenophylla. The chemical compositions of three species (B. pauciflosculosa, B. reticularioides, and B...
The species of the aromatic plant family Apiaceae are mainly used as spices and foods, but the family also includes medicinal and some poisonous plant species. Due to the similar chemical compounds or aroma and morphology, the poisonous species are often mistaken for the edible aromatic species. It is therefore imperative to correctly identify the...
The chemically complex nature of botanically-derived ingredients calls for unique quality control processes by suppliers, manufacturers, and producers of herbal products. One of the universal regulatory requirements in industrialized nations is the appropriate testing for identity and authenticity of botanical materials that are to be used in consu...
At the molecular level, plant species can be identified using DNA loci either from nuclear or plastid genome with easily available universal oligonucleotides, a technique called DNA barcoding. However, this is possible when single-species plant material is present but may not work on a mixture of plants species. Another disadvantage is that using u...
Currently two types of Chamomile are used for medicinal purposes and beauty products. Both, Matricaria recutita L and Anthemis nobilis L, belong to the family Asteraceae (Compo-sitae) and are used to treat similar health problems. However, they differ in their biologically active compounds. The use of DNA barcoding was explored to distinguish betwe...
Background:
The fungus Diaporthe eres was isolated from a fungal pathogen-infected leaf of Hedera helix (English Ivy) exhibiting necrosis. It is hypothesized that the causative fungus produces phytotoxins as evidenced by necrotic lesions on the leaves.
Results:
The fungus was isolated and grown in Czapek Dox broth culture medium and potato dextr...
Yams are species of the genus Dioscorea (family Dioscoreaceae), which consists of approximately 630 species. The majority of the world production of yams occurs in Africa with 58.8 million t annually, but they are also produced in the Americas and Asia. The saponins in yams have been reported to possess various properties to improve health. The tub...
In the past decades, the use of traditional medicine has increased globally, leading to a booming herbal medicine and dietary supplement industry. The increased popularity of herbal products has led to a rise in demand for botanical raw materials. Accurate identification of medicinal herbs is a legal requirement in most countries and prerequisite f...
The identification of raw plant material can be done by organoleptic characterization, macroscopic, microscopic and chemical analysis, and DNA barcoding. On the other hand the identification of processed plant material, for example in dietary supplements, can be difficult as the plant material often loses characteristic morphological features durin...
The genetic stability of Stevia rebaudiana Bertoni plants, propagated through in vitro stored synthetic seeds was assessed. In vitro grown micro shoots of Stevia rebaudiana were encapsulated in 5% sodium alginate and 50 mM CaCl2. The synthetic seeds were stored in vitro for 4 months and re-grown under the tissue culture conditions (16-h photoperiod...
The present study describes a simple, efficient and one step regeneration system for rapid shoot proliferation and in vitro rooting of Cannabis sativa nodal explants using meta-topolin (mT), an aromatic natural cytokinin. The best response in terms of explants producing maximum number of shoots with maximum shoot length and percent explants produci...
Ginkgo biloba is one of the oldest living tree species and has been extensively investigated as a source of bioactive natural compounds, including bioactive flavonoids, diterpene lactones, terpenoids and polysaccharides which accumulate in foliar tissues. Despite this chemical diversity, relatively few enzymes associated with any biosynthetic pathw...
Zinnia elegans Jacq. plants are infected by a fungus that causes dark red spots with necrosis on leaves, particularly in late spring to the middle of summer in the Mid-South of the United States. This fungal disease causes the leaves to wilt and eventually kills the plant. The fungus was isolated, cultured in potato dextrose broth, and identified a...
The strong flavor of licorice, which comes from the Glycyrrhiza root extract, is either loved or very much disliked. Licorice flavor is found in probably half of the many traditional Chinese medicine prescription to improve their flavor. The extract is made from three authentic licorice drug plants: G. uralensis, G. glabra and G. inflata. G. uralen...
Hoodia gordonii (Asclepiadacecae) a native of Kalahari deserts of South Africa, Namibia, and Botswana is one of the most prevalent herbal supplements for weight loss. The appetite suppressant properties are attributed to P57AS3, an oxypregnane steroidal glycoside. At the molecular level, the enzymes involved in biosynthesis of triterpenes and stero...
In this study, Angelica dahurica and Angelica pubescentis rot essential oils were investigated as pest management perspective and root samples were also analyzed genetically using the nuclear ribosomal internal transcribed spacer (ITS) region as a DNA barcode marker. Angelica pubescentis root essential oil demonstrated moderate antifungal activity...
Few studies have addressed the presence and bioactivity of endophytic fungi living in plantlets growing under in vitro conditions. After unfruitful attempts to grow axenic shoot cultures of the medicinal plant Smallanthus sonchifolius (yacon) were made, healthy shoots grew on half strength Murashigue and Skoog media supplemented with 2.2 μM benzyla...
Few studies have addressed the presence and bioactivity of endophytic fungi living in plantlets growing under in vitro conditions. The objectives of the study were: 1) to identify a fungus UM 109 growing as endophytes of autotrophic cultures of the medicinal plant Smallanthus sonchifolius (yacon), and 2) to isolate the compounds produced by this en...
Inter-simple sequence repeat (ISSR) markers were used to evaluate the genetic fidelity of in vitro propagated and hardened plants of Stevia rebaudiana Bert. Nodal segments containing axillary buds were used as explant and inoculated on Murashige and Skoog’s (MS) medium containing 3% (w/v) sucrose, 0.8% (w/v) agar supplemented with various concentra...
The endophytic fungal assemblages associated with Smallanthus sonchifolius (Poepp.) H. Rob. and Smallanthus uvedalius (L.) Mack. ex Small growing in vitro autotrophic cultures and in the greenhouse were identified and evaluated for their ability to produce bioactive compounds. A total of 25 isolates were recovered that were genetically closely rela...
A simple and efficient micropropagation protocol was developed for Stevia rebaudiana Bert. using nodal segment. Inter-simple sequence repeat (ISSR) markers were used to evaluate the genetic stability of the micropropagated and hardened plants. Total genomic DNA was extracted from 20mg dried leaves of mother and randomly selected micropropagated pla...
The increasing utilization of synthetic (encapsulated) seeds for germplasm conservation and propagation necessitates the assessment of genetic stability of conserved propagules following their plantlet conversion. We have assessed the genetic stability of synthetic seeds of Cannabis sativa L. during in vitro multiplication and storage for 6 months...
Endophytic microorganisms living in tissues of ethno-medicinal plants appear to be potential new sources of bioactive compounds because of possible chemical contribution to the host's defense. In this study, two hosts of fungal endophytes, S. sonchifolius and S. uvedalius were evaluated for potential sources of compounds with antifungal properties....
Echinacea is one of the top ten selling medicinal herbs in Europe and United States. Commercially available formulations may contain different plant parts of three species (Echinacea purpurea, E. pallida, and E. angustifolia). Our study evaluates the diversity of microbial community associated with healthy E. purpurea clones and their ability to pr...
Plant-based medicines play an important role in the lives of human beings. Identification of active principles and their molecular targets from traditional medicine provides an enormous opportunity for modern drug development. Using modern biotechnology, plants of specific chemical composition can be mass propagated for the extraction of bulk activ...
Genetic markers separating Cannabis varieties have a practical utility for drug enforcement to connect marijuana samples with source populations and for pharmaceutical research to determine the identity of screened elite clones acquired from various sources. In the present study, we have reported simple sequence repeat (SSR) markers to differentiat...
The increasing utilization of synthetic seeds for germplasm conservation and propagation necessitates the assessment of genetic stability of conserved propagules following their plantlet conversion. The present study was undertaken to assess the genetic stability of synthetic seeds grown Cannabis sativa L. plants during in vitro multiplication and...
Tripterygium wilfordii Hook.f., known as Leigongteng (Thunder God Vine) in traditional Chinese medicine, has attracted much attention for its applications in relieving autoimmune disorders such as rheumatoid arthritis and systemic lupus erythematosus, and for treating cancer. Molecular analyses of the ITS and 5S rDNA sequences indicate that T. hypo...
The genus Chionanthus (Oleaceae Hoffmans. & Link) includes deciduous or evergreen trees and shrubs distributed widely in tropical and sub-tropical areas, including a few temperate species. Although Chionanthus species are planted as ornamental garden plants and commercialized for natural products, genetic information for Chionanthus spp. is lacking...
Hoodia gordonii, a succulent plant growing in African arid regions, is used as a botanical dietary supplement for weight loss. The increasing concerns on the quality and safety of Hoodia products call for the needs of more science-based information, as well as objective and efficient tools for inspection. In the present study, NMR fingerprinting an...
Sequence-characterized amplified region (SCAR) markers were used to identify female plants at an early developmental stage in four different varieties of Cannabis sativa. Using the cetyl trimethylammonium bromide (CTAB) method, DNA was isolated from two-week-old plants of three drug-type varieties (Terbag W1, Terbag K2, and Terbag MX) and one fiber...
The antitussive Chinese herb Madouling derived from Aristolochia species is banned due to aristolochic acid-induced nephropathy. A substitute is found dispensed as Madouling in Taiwan. This study aims to determine the source plant and verify the antitussive properties of the Madouling substitute used in Taiwan.
Forensically informative nucleotide s...
The construction of microsatellite-enriched libraries is an indispensable tool to search for molecular markers as complete genome sequences are still not available for the majority of species of interest. Numerous protocols are available in the literature for the construction of these libraries; however, sometimes their low efficiency or lack of op...
Questions
Questions (8)
The PCR products I want to analyze on the 2100 Bioanalyzer contains DNA loading dye for agarose gel analysis (sucrose and orange G). I added it before loading on an agarose gel. Now I want to analyze the same products on the DNA chip. I was wondering if I can still load the samples on the DNA chip or if this agarose loading dye would interfere with the analysis on the chip.
Thanks.
Hi,
I need to clone 30-40 PCR products. I tried direct sequencing of the products but found out that they are mixed and result in overlapping peaks if directly sequenced. I want to clone these products so I can sequence 4-8 resulting colonies.
I find it tedious and boring to do single column PCR extractions of the products prior to ligation. Any suggestions to avoid the PCR clean up step and directly clone them into a vector, and to avoid that I clone the primers (exosap step needed)? Also, any good suggestions how to plate the resulting transformations? I would only need up to 10 colonies per ligation. 30-40 plates is a lot... I only have access to Sanger sequencing, not to NGS.
I was considering trying various dilution steps of the transformation so I can plate more than one transformation on a plate. Was thinking undiluted transformation, 1:10 dilution, 1:100 dilution and then drop 20 uL or so on a designated spot on a plate so I can spot more than one transformation event on a single plate. Then next day, pick the colonies.
Thank you in advance for your suggestions!
Natascha
I want to detect a protein that is present in full length or truncated. I mostly want to detect the truncated version, about 14 AA from the amino-terminus but the antigenicity of the peptide is very poor. Is there a way to modify the sequence to increase its antigenicity?
Thanks!
I performed PCR on genomic DNA with gene region specific primers that have a M13 adapter, which resulted in two PCR products. I treated the PCR products with ExoSap (primer removal) and cloned into vector pMiniT (NEB). Single colonies were subjected to colony PCR using M13F and M13R primers. It resulted either in single (lane 1 bigger, 14 smaller) or double bands (lane 2, 5) where I expect to see only single products.
M13 primers do not bind in the vector (I checked the sequence by BLAST and Clone manager) and therefore can only amplify from the fragment.
Why am I seeing two fragments from some of the colonies? Its 25 cycles at 50°C annealing.
Could some of the colonies have two different plasmids, some of them with loss of sequence due to homologous recombination within the cloned fragment?
I want to use oligonucleotides to pull out DNA fragments from a library. I don't want to use biotin/streptavidin magnetic beads because need to work at temperatures above 45°C (streptavidin/biotin bond breaks at temperatures above 40-50°C). Are there vendors that couple oligos to magnetic beads or can you recommend a kit/method to make it myself? I have found but not used yet the BcMag Quick oligo-DNA conjugation kit and Dynabeads® MyOne™ Carboxylic Acid. Can you recommend them? Thank you.
I have designed 30 oligo pairs and found out that some of them can build dimers. I would like to use a software to help me suggest which of the 30 oligos can be in one pool and which should go into a different pool. Maybe a total of 5 pooling mixes.
