Jan Schripsema

Jan Schripsema
Universidade Estadual do Norte Fluminense · Laboratory of Chemical Sciences – LCQUI

Professor

About

165
Publications
20,295
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
3,850
Citations

Publications

Publications (165)
Article
The ¹H NMR spectra obtained from 56 different paracetamol tablets were thoroughly investigated to analyse and quantify besides paracetamol, the excipients and eventual minor components present in the formulations. In the NMR spectra the amide-iminol tautomerism of paracetamol was observed, with the iminol form present at a quantity of only 0.80% of...
Article
Adulteration of essential oils is a common and serious problem. Adequate and fast methods are required to establish the authenticity and purity. GC-MS, ¹H and ¹³C NMR were compared in combination with similarity calculations as well as differential spectroscopy and chromatography for the authentication and determination of purity of vetiver essenti...
Article
Full-text available
Organic phosphorus (Po) plays an important role in tropical forest nutrition on strongly-weathered soils. However, of its role in Eucalyptus nutrition little is known. For this purpose, soil P forms were determined by NaOH-Na2EDTA extraction and ³¹P nuclear magnetic resonance spectroscopy (³¹P NMR) at 10 sites of Eucalyptus plantations in Brazil. T...
Article
Baobab seed oil, obtained from the seed kernel of Adansonia digitata from Southern Africa, has experienced an increase in global demand. ¹H and ¹³C NMR was used for the authentication of the baobab oils, allowing for the quantification of the characteristic cyclopropane and cyclopropene fatty acids. Through similarity analysis, differential NMR spe...
Article
The illegal trade in counterfeit and fake drugs is a worldwide multi-billion dollar industry, not only generating enormous economic losses, but health problems for the general population, through direct toxicity, treatment failure and the increased generation of antibiotic resistance. Techniques for high-throughput testing of suspect medicines are...
Article
Cryptococcosis, caused by Cryptococcus spp., is an invasive fungal infection of the central nervous system, associated with high mortality, affecting mainly immunocompromised patients. Due to the development of resistance to the current therapy, there is an urgent need for less toxic and more effective antifungal agents. In this study, we describe...
Article
Ethnopharmacological relevance: Cissampelos sympodialis Eichler (Menispermaceae) is popularly used in northeastern Brazil for the treatment of respiratory diseases such as bronchitis and asthma. Despite many pre-clinical pharmacological studies, the compounds mediating the anti-asthma activity of polar extracts of Cissampelos sympodialis leaves ha...
Article
Full-text available
The Latin American medicinal plant carqueja got its name from a morphologically similar plant from the Iberian peninsula. The popular name came in general use to indicate all species from the section Caulopterae from the genus Baccharis, which are often difficult to distinguish. Phytochemical studies indicate that the different species from this se...
Article
Full-text available
To increase the limited knowledge about phosphorus (P) species in strongly weathered soils of agroforests in tropical regions, the soil organic P was determined in different cacao (Theobroma cacao L.) agroforestry systems from the Atlantic forest region of Brazil, varying in age and phosphate fertilizer application. For this purpose NaOH-EDTA extra...
Article
This article focuses on the practical and potential applications of metabolomics. The different steps of metabolomics experiments are discussed, from the initial design, sampling, and measurements, to chromatograms and spectra, pretreatment of data, and interpretation of data to find marker compounds. The article discusses how to choose the analyti...
Article
Full-text available
Introduction In NMR based metabolomics there is a need for tools to easily compare spectra and to extract the maximum of information from the data. Objectives The calculation of similarity and performing differential NMR spectroscopy provides important additional information for classification and validation in metabolomics experiments. Methods F...
Poster
Full-text available
The use of 31P nuclear magnetic resonance spectroscopy in the soil showed that the leguminous trees inoculated with the diazotrophic bacteria and arbuscular mycorrhizal fungi can increase soil P concentrations by cycling and accumulation of organic and inorganic compounds of P. The planting of leguminous trees species for recovering degraded lands...
Chapter
Metabolomics is the area of research, which strives to obtain complete metabolic fingerprints, to detect differences between them, and to provide hypothesis to explain those differences [1]. But obtaining complete metabolic fingerprints is not an easy task. Metabolite extraction is a key step during this process, and much research has been devoted...
Article
Foodborne diseases and antibiotic resistant bacteria have become a serious worldwide public health problem. In this context, this study was carried out to describe the chemical composition and antimicrobial activity of the essential oils from three Brazilian Ocimum species, since essential oils are considered safe. The essential oils were analyzed...
Poster
Full-text available
Finalist of the Scientific Dissemination Contest in the IV SIMPÓSIO MINEIRO DE CIÊNCIA DO SOLO (2017)
Article
Biopolymers as polyhydroxyalkanoates (PHA) composed by different co-monomers 3-hydroxybutyrate and 3-hydroxyhexanoate [P(3HB-co-3HHx)] has attracted interest since its properties are similar to low density polyethylene. Burkholderia sacchari produces this copolymer with a very low 3HHx molar fraction, about 2 mol%. B. sacchari mutant (unable to pro...
Poster
Full-text available
Our hypothesis was that the diversity of species and concentrations of P in Yellow Argissol (Ultisol) can be influenced by different types of cacao agroforestry systems (Theobroma cacao L.) with low input of phosphate fertilizer. The phosphorus forms were determined by solution 31P-NMR spectroscopy. Conclusions: The cacao agroforests exhibited the...
Article
Full-text available
Cultures from the cyanobacterial strain Microcystis aeruginosa PCC 7806 submitted to nutrient limitation become chlorotic. When returned to nutrient rich conditions these cultures regain their green colour. The aim of this study was to verify whether the cells in these cultures could be considered resting stages allowing the survival of periods of...
Chapter
Metabolomics can be defined as the area of research that strives to obtain complete metabolic fingerprints, to detect differences between them and to provide hypothesis to explain those differences. This area of research is still rapidly developing into a powerful tool in the study of all types of organisms.This chapter focuses on the practical and...
Article
Because metabolomics is still a recent area of research, continuous development takes place leading to further improvements and adaptations of experimental protocols. In this chapter an overview is given of the sequence of experimental procedures of typical metabolomic experiments. The focus is on NMR based metabolomics, but many aspects apply to o...
Article
Evaluation of the capability of Burkholderia sacchari to incorporate different monomers into PHA. Thirty different carbon sources were evaluated as co-substrates for B. sacchari growing on glucose with the intention to promote the incorporation of different monomers into the PHA produced by this species. With odd-numbered fatty acids, incorporation...
Article
Two cell lines of Tabernaemontana divaricata derived from the same suspension culture were compared with respect to their biotransformation capacity. One is a high indole alkaloid-producing culture which accumulated mainly O-acetylvallesamine. The other cell line biosynthesizes terpenoid indole alkaloids in much lower amounts. Both cell lines were...
Article
Guided by the acetylcholinesterase inhibiting activity, the bisindole alkaloid 3'-R/S-hydroxyvoacamine was isolated from a stem extract of Tabernaemontana divaricata, a plant used in Thailand in traditional rejuvenation remedies for improving the memory. The structure of the alkaloid was elucidated by extensive use of NMR spectroscopy and the compl...
Article
Full-text available
Ethanol extract obtained from dried leaves of Acmella oleracea afforded after a liquid/liquid partition procedure a larvicidal hexane fraction (LC50 = 145.6 ppm) and a non larvicidal dichloromethane one. From the inactive fraction, three amides were identified, two new structures, named deca-6,9- dihydroxy-(2E,7E)-dienoic acid isobutylamide (1), de...
Article
Full-text available
2-acetyl physcion (2-acetyl-1,8-dihydroxy-6-methoxy-3-methyl-9,10-anthraquinone, 2), a rare anthraquinone, was isolated from Senna macranthera var. nervosa (Vogel) H.S. Irwin & Barneby (Fabaceae). The chemical structure was elucidated and all (1)H and (13)C NMR chemical shifts were assigned by NMR one- ((1)HNMR, {(1)H}-(13)CNMR, and APT-(13)CNMR) a...
Article
Full-text available
In metabolomics the aim is to detect and quantify all metabolites present in a certain organism, tissue or cell at a specific moment. One of the major problems in the analysis is the incomplete extraction [1]. In NMR based metabolomics generally aqueous solutions are used. In studies with humans or animals, where the samples are generally derived f...
Article
Full-text available
This study evaluated the influence of different fertilizers and soil water availability on the content and chemical composition of essential oil from alpinia leaves. The experiment was arranged in a randomized block design in a splitplot scheme, with three replicates. The plots corresponded to two limits of water availability at soil [LWD1 - reduct...
Article
The crude extracts of HYPERICUM species native to South Brazil showed analgesic and antidepressant-like effects in rodents. The chemical characterization of these species revealed that they are rich in flavonoids and phloroglucinol derivatives. In the present study a detailed investigation was performed on the activities of hyperoside (HYP), a comm...
Article
The antioxidant activity of leaf extracts from Jacaranda puberula Cham., Bignoniaceae, was assayed by the DPPH (2,2-diphenyl-1-picryl-hydrazyl) free radical scavenging method. Three phytomedicines (F1, F2, and F3) used as blood depurative, were tested by the same method. The free radical scavenger potential was measured by the discoloration of the...
Article
Fruit flesh gelling in papaya fruits is a typical post-harvest disorder. The aspect of the fruit flesh changes to more rigid and translucent, and also turns darker. It occurs close to the seeds and therefore the external appearance of the fruit is not changed. No information about this disorder is available in the literature. For the metabolomic in...
Article
The present state-of-the-art of NMR in plant metabolomics is reviewed. Attention is paid to the diff erent practical aspects of the application of NMR. The sample preparation, the measurement of the spectrum, quantitative aspects and data analysis are discussed. Each stage has its specifi c problems, which are pointed out and recommendations are ma...
Article
Full-text available
The title compound, C(14)H(11)NO(2), features an essentially planar mol-ecule, the r.m.s. deviation for the 17 non-H atoms being 0.035 Å. This conformation is stabilized by an intra-molecular O-H⋯N hydrogen bond that results in the formation of an S(6) ring. In the crystal structure, methyl-ene-hydr-oxy C-H⋯O contacts result in a supra-molecular ch...
Article
The four stereoisomers of small bacteriocin, an autoinducer of the symbiotic nitrogen-fixing bacterium Rhizobium leguminosarum, were synthesized via a versatile methodology for 3′-hydroxyacyl homoserine lactones based on the Nagao asymmetric aldol reaction. The synthetic isomers were much less effective at inhibiting the growth of R. leguminosarum...
Article
The separation of butter or margarine into polar (soluble in water) and apolar fractions (soluble in chloroform) and subsequent analysis of these fractions by 1 H NMR permits a comprehensive analysis of its constituents. In the polar fraction the preservatives benzoic and sorbic acid, the organic acids citric, lactic, butyric, acetic, and formic ac...
Article
Species of Hypericum accumulate phenolic compounds with the phloroglucinol substitution pattern, and there are many reports of such substances isolated from the aerial parts of the plants. In this study, flowers of plants grown in south Brazil were analyzed by means of HPLC, verifying the presence of benzopyrans in H. polyanthemum and dimeric phlor...
Article
From the aerial parts of Pentas lanceolata, belonging to the family Rubiaceae, a series of iridoid glucosides was isolated by preparative HPLC. Seven iridoid glucosides were identified. Besides asperuloside and asperulosidic acid, characteristic iridoids for Rubiaceae, five new iridoids were isolated, namely, tudoside (1), 13R-epi-gaertneroside (2)...
Article
Hypericum connatum (Guttiferae) is used in southern Brazil in the treatment of lesions in the mouth, often related to acute herpetic gingivo-stomatitis. The chemical investigation of the plant revealed the presence of phloroglucinol derivatives and flavonoids. From the n-hexane extract of the aerial parts a phloroglucinol derivative, hyperbrasilol...
Article
Himatanthus sucuuba. Himatanthus sucuuba and Plumeria rubra are used in folk medicine in Brazil to treat various ailments. The isolation of the new iridoid 15-demethylisoplumieride from the bark of Plumeria rubra L. var. acutifolia (Ait) Woodson and latex of Himatanthus sucuuba (Spruce) Woodson is reported. Other iridoid glycosides were obtained fr...
Article
Antibacterial and antifungal properties of wax and hexane extracts of Citrus spp. peels were tested using bioautographic and microdilution techniques against three plant pathogenic fungi (Penicillium digitatum, Curvularia sp., and Colletotrichum sp.), two human pathogens (Trichophyton mentagrophytes and Microsporum canis), and two opportunistic bac...
Article
Full-text available
Antibacterial and antifungal properties of wax and hexane extracts of Citrus spp. peels were tested using bioautographic and microdilution techniques against three plant pathogenic fungi (Penicillium digitatum, Curvularia sp., and Colletotrichum sp.), two human pathogens (Trichophyton mentagrophytes and Microsporum canis), and two opportunistic bac...
Article
Full-text available
A mixture of the two new flavonols 8-hydroxy-3, 4', 5, 6, 7-pentamethoxyflavone (1) and 8-hydroxy-3, 3', 4', 5, 6, 7-hexamethoxyflavone (2) was isolated from a commercial sample of Citrus aurantifolia. An array of one- (1HNMR, {1H}-13C NMR, and APT-13C NMR) and two-dimensional NMR techniques (COSY, NOESY, HMQC and HMBC) was used to achieve the stru...
Article
Formation of 2,4,5-triaryl-4,5-dihydro-1H-imidazoles, (1), from aryl aldehydes. Crystal structures of cis-(1: arylDpyridin-2-yl), {trans-[(1: arylDpyridin-2-yl)H] + [OAc] ¡ ·3H 2 O}, {cis-[1: arylDthien-2-yl]·0. Abstract The preparations of cis-2,4,5-triaryl-4,5-dihydro-1H-imidazoles, (aryl D thien-2-yl or pyridin-2-yl) from aryl aldehydes, ammoniu...
Article
A mixture of the two new flavonols 8-hydroxy-3,4',5,6,7-pentamethoxyflavone (1) and 8-hydroxy-3,3',4' 5,6,7-hexamethoxyflavone (2) was isolated from a commercial sample of Citrus aurantifolia. An array of one- ((HNMR)-H-1, {H-1}-C-13 NMR, and APT-C-13 NMR) and two-dimensional NMR techniques (COSY, NOESY, HMQC and HMBC) was used to achieve the struc...
Article
Cyathenosin A, a spiropyranosyl derivative of protocatechuic acid was isolated from the stem pith of Cyathea phalerata Mart. Its structure was determined by MS, 1D and 2D NMR spectroscopic analyses and confirmed by single crystal X-ray analysis. Cyathenosin A is the first example of a naturally occurring compound containing a spirocyclic orthoester...
Article
Full-text available
From the aerial parts of Pentas lanceolata, belonging to the family Rubiaceae, a series of iridoid glucosides was isolated by preparative HPLC. Seven iridoid glucosides were identified. Besides asperuloside and asperulosidic acid, characteristic iridoids for Rubiaceae, five new iridoids were isolated, namely, tudoside (1), 13R-epi-gaertneroside (2)...
Article
Recebido em 2/8/05; aceito em 17/2/06; publicado na web em 6/7/06 PHENOLIC CONSTITUENTS AND TERPENOIDS ISOLATED FROM THE ROOTS OF Andira fraxinifolia (FABACEAE). Sitosterol, stigmasterol, betulinic acid, lupeol, 3-O-β-D-glucopiranosylsitosterol, 3-O-α-L-rhamnopiranosylchromone, 5,7-dihydroxy-4'-methoxyisoflavone, 3',5,7-trihydroxy-4'-methoxyisoflav...
Article
[Structure: see text] Citrifolin A was revised to dehydromethoxygaertneroside (2). Citrifolinoside and yopaaoside A were found to be identical, and their structures were revised to the new structure dehydroepoxymethoxygaertneroside (5). Yopaaoside B was revised to citrifolinoside A (9), and morindacin was revised to borreriagenin (11).
Article
Sitosterol, stigmasterol, betulinic acid, lupeol, 3-O-beta-D-glucopiranosylsitosterol, 3-O-alpha-L-rhamnopiranosylchromone, 5,7-dihydroxy4'-methoxyisoflavone, 3',5,7-trihydroxy-4'-methoxyisoflavone and a mixture of two rel-2R,3S-3-O-a-L-rhamnopiranositflavanonots were isolated from the roots of Andirafraxinifolia. Their structures were established...
Article
Chemical investigation of ethanolic extracts of the leaves and stems of Baccharis illinita resulted in the isolation and identification of retusin, quercetin-3, 7, 4'-trimethyl ether, aromadendrin-7-methyl ether, 3-(4-hydroxyphenyl)-2-propenoic acid (E and Z) hexacosyl ester, 3-(3, 4-dihydroxyphenyl)-2-propenoic acid (E) hexacosyl ester and hexacos...
Article
The (1)H and (13)C NMR spectra of 5-acetyl-7,4'-dimethoxyflavone-(6-8'')-5''-acetyl-7'',4'''-dimethoxyflavone, a new agathisflavone derivative, were completely assigned on the basis of 1D and 2D NMR techniques.
Article
Full-text available
RESUMO: Do extrato butanólico de Croton campestris St. Hill. (Euphorbiaceae) foram isolados quatro fl avonóides, todos O-glicosídeos da quercetina. Estas substâncias foram identifi cadas como 3-O-β-D-apiofuranosil-(1→2)-galactopiranosil quercetina (1), 3-O-β-D-galactopiranosil quecetina (hiperina) (2), 3-O-α-L-arabinopiranosil quercetina (guaijaver...
Article
A complete procedure is described for the extraction, detection and quantification of anatoxin-a in biological samples. Anatoxin-a is extracted from biomass by a routine acid base extraction. The extract is analysed by GC–MS, without the need of derivatization, with a detection limit of 0.5 ng. A method was developed for the accurate quantification...
Article
Two new benzophenones were isolated from the leaves of Hypericum carinatum. Their structures were established on the basis of 2D NMR spectroscopic analyses and mass spectrometry as cariphenone A (6-benzoyl-5,7-dihydroxy-2,2,8-trimethyl-2H-chromene) (1) and cariphenone B (8-benzoyl-5,7-dihydroxy-2,2,6-trimethyl-2H-chromene) (2). Five known compounds...
Article
Ground and first excited singlet state tautomerization of phenyl-lapimidazole (PLI) was studied by absorption, fluorescence, time-resolved fluorescence, NMR spectroscopy and molecular orbital calculations. In the non-protic solvents cyclohexane and DMSO, PLI is observed by NMR, static and time-resolved fluorescence spectroscopy to exist in two diff...
Data
Baccharis illinita DC, commonly known as ''chá ventura'' or ''erva milagrosa'' (family Asteraceae) is an annual sub-shrub with yellowish flowers that grows in natural grasslands. Flowers of Baccharis illinita DC were collected in Serra do Falcão, Minas Gerais, and identified by the botanist José Badini. A voucher speci-men (OUPR No. 3450) has been...
Article
The culture of plant cells on a large scale in bioreactors has been shown to be feasible. The price of a plant cell biotechnological product is mainly governed by the slow growth of plant cell cultures, making the depreciation costs of the bioreactor the major cost-determining factor. A review of the production of the economically important alkaloi...
Article
Major problems associated with plant cell suspension cultures are the variability and instability of the cultures. Therefore, characterization of a suspension culture in every experiment is necessary to allow a comparison between different experiments. For this purpose, some new techniques were developed. A technique for growth characterization has...
Article
The air dried and powdered plant material, aerial parts, was extracted in a Soxhlet apparatus with petroleum ether for 12 h and then the extract was evaporated to dryness under reduced pressure. The petroleum ether extract was analyzed by TLC on silica gel. The main products were isolated by column chromatography on silica gel using a n-hexane/EtOA...
Article
An HPLC method with UV detection has been developed and validated in order to quantify quadranguloside, the main saponin of the leaves of Passiflora alata. The analysis was achieved by simple isocratic elution (with acetonitrile:aqueous phosphoric acid) using a Nova-Pak phenyl column. The amount of quadranguloside present in aqueous extracts from l...
Article
Full-text available
From leaves of Psychotria leiocarpa, an indole alkaloid was isolated to which the structure N,beta-D-glucopyranosyl vincosamide (1) was assigned. This represents the first report of an N-glycosylated monoterpenoid indole alkaloid. In field-grown plants highest amounts of 1 were found in the leaves (2.5% of dry wt) and fruit pulp (1.5% dry wt). Lowe...