Anthracene Derivatives Research Articles

Influence of Seasonality on Phytochemical Composition, Phenolic Content and Antioxidant Activity of Neoglaziovia variegata (Bromeliaceae)

The production of phytochemicals in plants can be influenced by several factors. This work evaluated the influence of seasonality on phytochemical composition, phenolic content, and antioxidant activity of Neoglaziovia variegata. The leaves were harvested for a year. Phytochemical characterization by thin-layer chromatography indicated the presence of anthocyanins, anthraquinones, anthracene derivatives, flavonoids, tannins, monoterpenes, diterpenes, triterpenes, and steroids in the leaves collected in all months, and coumarins in leaves of 4 of the 12 months of collection. The antioxidant activity, evaluated in vitro, ranged from 33.0 to 86.1% inhibition of DPPH• and from 36.2 to 97.8% inhibition of ABTS•+. The total phenolic content, determined using Folin-Ciocalteu reagent, varied between 21.5 and 65.8 mg GAE/g. Phenolic acids and flavonoids were determined by HPLC-DAD, with higher concentrations of kaempferol (0.47-3.57 mg/g), p-coumaric (0.19-3.59 mg/g) and ellagic (0.26-3.31 mg/g) acids. The Principal Component Analysis (PCA) indicated the separation of the leaf samples according to the season. It was demonstrated the influence of seasonality on the antioxidant activity and phytochemical composition of N. variegata leaves and that this species is rich in secondary metabolites of different classes, with potential applications in several areas, such as pharmaceutical and food.

Nondoped, deep-blue, organic light-emitting diodes with low-efficiency roll-off based on a simple anthracene–triazole hybrid fluorescent molecule

Anthracene is a traditional blue-fluorescence group with excellent electron-transporting ability and high fluorescence quantum efficiency. With the increasingly wide application of anthracene derivatives in electroluminescence (EL) fields, how the molecule is constructed becomes particularly critical owing to the natural flat conformation of the anthracene group, which quenches fluorescence in the aggregated state. In this study, we designed and synthesized a simple donor–acceptor-type molecule by hybridizing anthracene with triazole [3-(4-(anthracen-9-yl)phenyl)-4,5-diphenyl-4H-1,2,4-triazole (ANTZ)]. In this molecule, anthracene acts as an electron donor, and the triazole unit with a twisting spatial construction and electron-withdrawing ability can not only inhibit the flat-stacking effect between anthracene and anthracene but also demonstrate carrier-transport ability to mimic anthracene. The optimized nondoped, deep-blue Device I using ANTZ as an emitter exhibits deep-blue-fluorescence emission with smaller Commission Internationale de I'Eclairage (CIEy) coordinates of 0.13, a maximum external quantum efficiency (EQE) of 3.3%, and a low-efficiency roll-off of 3.0%, which was a significant improvement relative to Device II using a traditional 2-methyl-9,10-bis(naphthalen-2-yl)anthracene emitter. The superior EL properties of Device I suggest its effectiveness as a molecular design for deep-blue emitters based on anthracene derivatives.

An Approach to Developing Cyanines with Simultaneous Intersystem Crossing Enhancement and Excited-State Lifetime Elongation for Photodynamic Antitumor Metastasis.

Heavy-atom-based photosensitizers usually exhibit shortened triplet-state lifetimes, which is not ideal for hypoxic tumor photodynamic therapy. Although several heavy-atom-free photosensitizers possess long triplet-state lifetimes, the clinical applicability is limited by their short excitation wavelengths, poor photon capture abilities, and intrinsically hydrophobic structures. Herein we developed a novel NIR heavy-atom-free photosensitizer design strategy by introducing sterically bulky and electron-rich moieties at the meso position of the pentamethine cyanine (Cy5) skeleton, which simultaneously enhanced intersystem crossing (ISC) and prolonged excited-state lifetime. We found that the 1O2 generation ability is directly correlated to the electron-donating ability of the meso substituent in cyanine, and the excited-state lifetime was simultaneously much elongated when the substituents were anthracene derivatives substituted at the 9-position. Our star compound, ANOMe-Cy5, exhibits intense NIR absorption, the highest 1O2 quantum yield (4.48-fold higher than Cy5), the longest triplet-state lifetime (9.80-fold longer than Cy5), and lossless emission intensity (nearly no change compared with Cy5). Such excellent photophysical properties coupled with its inherently cationic and hydrophilic nature enable the photosensitizer to realize photoablation of solid tumor and antitumor lung metastasis. This study highlights the design of a new generation of NIR photosensitizers for imaging-guided photodynamic cancer treatment.

A near-infrared turn-on fluorescent probe for the rapid detection of selenocysteine and its application of imaging in living cells and mice

Selenocysteine (Sec) plays critical roles in many physiological and pathological processes of human beings, thus it is of great significance to develop accurate methods for detecting and visualizing Sec. Herein, a new anthracene derivative (YZ-M5) as a near-infrared (NIR) fluorescent probe for sensing Sec was designed. Based on the target-induced modulation of the intramolecular charge transfer (ICT) process of the probe, YZ-M5 can display a rapid strong NIR fluorescence enhancement at 660 nm for Sec within 5 min. The quantitative detection range for Sec is 0–40 μM with a low detection limit of 18.5 nM. YZ-M5 also showed high selectivity and sensitivity, as well as the capability for identification of Sec in living cells and mice.

Development of Dermatological Ointment based on Aloe arborescens juice

The purpose of this study is to select the optimal ointment base for the creation of a soft dosage form, to develop methods for standardizing dermatological ointment based on Aloe arborescens juice and to study antibacterial activity. The choice of the optimal ointment base, ensuring the maximum therapeutic effect of the ointment, was made. Ointments were prepared in accordance with the physical-chemical properties of the components of the basics. The criterion for evaluating the effectiveness of the used ointment bases was the degree of release of the active substances (anthracene derivatives). During the studies, antimicrobial activity was determined in the in vitro experiment. The comparative determination of the antimicrobial activity of ointment bases and juice of Aloe arborescens was performed by direct diffusion into agar. To develop the method of quantitative determination, the absorption spectra of Aloe arborescens juice and ointment extraction with 60% ethyl alcohol were studied. The optical density of the solution on the spectrophotometer at a wavelength of 396nm was measured. The quantitative content of the total active substances in the ointment, calculated on barbaloin was determined by using UV spectrophotometry.

Anthracene-based emitters for highly efficient deep blue organic light-emitting diodes with narrow emission spectrum

Organic light-emitting diodes (OLEDs) are expected to support the future applications in flat-panel displays and solid-state lightings owing to their advantages of flexibility, light weight, high resolution, energy conservation, etc. Achieving efficient deep blue electroluminescence with excellent color purity (narrow emission) remains a big challenge for OLEDs. Herein, two anthracene derivatives, PIAnTPh and PyIAnTPh, with a hybridized local and charge transfer (HLCT) excited state are obtained by attaching the large periphery groups of phenanthroimidazole/pyrenoimidazole and terphenyl unit to the 9,10-positions of anthracene. The sterically asymmetric strategy can efficiently suppress the unfavorable intermolecular interactions and realize deep blue emission. The introduction of neutral terphenyl unit avoids the potential reduction of fluorescence quantum yield from strong charge transfer (CT) characteristics. More importantly, the relatively weak CT state and the rigid molecular structure can significantly reduce the vibrational motion to obtain relatively narrow emission spectra. The doped devices based on PIAnTPh and PyIAnTPh show strong deep blue electroluminescence with CIE coordinates of (0.15, 0.06) and (0.15, 0.07), high color purity, and narrow full width at half maxima (FWHM) of merely 50 and 52 nm, respectively, meeting well with the EBU standard. The EQEs are as high as 8.09% and 8.44% for PIAnTPh and PyIAnTPh, which are among the state-of-the-art deep blue OLEDs.

Determination of Anthracene Derivatives in Herbal Medicines

The relevance of this study stems from the need for alignment of test methods used for identification and assay of anthracene derivatives in herbal preparations and herbal medicinal products. The aim of the study was to analyse Russian and international quality standards and to identify the most specific and sensitive test methods that could be used for herbal medicines containing anthracene derivatives. The comparative analysis of requirements in the Identification, Determination of major classes of bioactive compounds, and Assay parts of the Russian and foreign pharmacopoeial monographs for herbal preparations and herbal medicinal products containing anthracene derivatives, demonstrated that the main test method used for identification is thin layer chromatography, while assays most often rely on spectrophotometry. The so-called “consistent standardisation” principle is implemented in the Russian quality standards as regards alignment of methods used for anthracene derivative determination in herbal preparations (i.e. active pharmaceutical ingredients, APIs) and herbal medicinal products containing these APIs. The comparative analysis of requirements in the Russian and foreign quality standards for herbal medicines containing anthracene derivatives demonstrated the need for elaboration of two general chapters: Qualitative analysis of anthracene derivatives in herbal medicines and Quantitative analysis of anthracene derivatives in herbal medicines.

A Photosensitive Polymeric Carrier with a Renewable Singlet Oxygen Reservoir Regulated by Two NIR Beams for Enhanced Antitumor Phototherapy.

Photodynamic therapy (PDT), which utilizes photosensitizer to convert molecular oxygen into singlet oxygen (1 O2 ) upon laser irradiation to ablate tumors, will exacerbate the already oxygen shortage of most solid tumors and is thus self-limiting. Herein, a sophisticated photosensitive polymeric material (An-NP) that allows sustained 1 O2 generation and sufficient oxygen supply during the entire phototherapy is engineered by alternatively applying PDT and photothermal therapy (PTT) controlled by two NIR laser beams. In addition to a photosensitizer that generates 1 O2 , An-NP consists of two other key components: a molecularly designed anthracene derivative capable of trapping/releasing 1 O2 with superior reversibility and a dye J-aggregate with superb photothermal performance. Thus, in 655nm laser-triggered PDT process, An-NP generates abundant 1 O2 with extra 1 O2 being trapped via the conversion into EPO-NP; while in the subsequent 785nm laser-driven PTT process, the converted EPO-NP undergoes thermolysis to liberate the captured 1 O2 and regenerates An-NP. The intratumoral oxygen level can be replenished during the PTT cycle for the next round of PDT to generate 1 O2 . The working principle and phototherapy efficacy are preliminarily demonstrated in living cells and tumor-bearing mice, respectively.

Trisubstituted Triptycenes: Toward the Preparation of Three-Dimensional Dendrimers

A synthesis of benzyl trisubstituted triptycenes is described. These triptycenes are precursors for producing a first generation (G1) poly(triptycylether) dendrimer, a derivative of known poly(arylether) dendrimers. The molecule necessary for the further elaboration into the eventual dendrimer is a carboxylic acid ester triptycene terminated with two ether substituents on another ring; the zero generation (G0). The synthesis begins with formation of the Diels-Alder adduct of benzoquinone and methyl 2-anthroate. This adduct is aromatized under basic conditions and the resulting anion trapped with a benzyl halide as an electrophile to form the trisubstituted triptycene. Access to the trisubstituted system is obtained through a highly improved, efficient and chromatography free preparation of anthracene derivatives, mainly methyl 2-anthroate.

Comparison of charge transport and opto-electronic properties of pyrene and anthracene derivatives for OLED applications

In this paper, three organic semiconductors such as 9-[(5-nitropyridin-2-aminoethyl)iminiomethyl]-anthracene (a), N'-((pyren-4-yl)methylene)isonicotinohydrazide (b), and novel organic semiconductor N-(2-((pyren-4-yl)methyleneamino)ethyl)-5-nitropyridin-2-amine (c) were prepared. Their structures were assessed using NMR and elemental analysis techniques. While compound (a) and compound (c) have the same wing unit ([(5-nitropyridin-2-aminoethyl) iminiomethyl]), compounds (b) and (c) have the same core unit (5-nitropyridin-2-amine). Based on TD-DFT and Marcus theories, we have explored the effects of molecular structure on the opto-electronic properties for OLED applications. Our results show that wing units of molecules impact more on the opto-electronics properties than on core units. The compounds (a) and (c) with the same wing unit have exhibited quite similar behaviors in terms of both structural and opto-electronic parameters. However, a similar situation has not been observed for compounds (b) and (c) with the same core unit. In conclusion, our results indicate that compounds (a) and (c) exhibit obvious advantages for OLEDs in terms of calculated opto-electronic and charge transport properties such as better absorption and emission parameters, lower energy gaps and reorganisation energies and higher charge mobility.

The current issues of standardization of <i>Aloe arborescens</i> Mill. leaves

BACKGROUND: Aloe arborescens Mill. leaves contain a whole complex of biologically active compounds (derivatives of anthraquinone, anthrone, pyrone, biopolymers, etc.) and are widely used in medical practice as raw materials for the production of anti-inflammatory, wound healing agents. The presence of anthracene derivatives in the leaves determines the laxative activity of raw plant materials and preparations. It emphasizes the importance of Aloe arborescens preparations for internal use in inflammatory diseases accompanied by constipation and decrease in secretory activity. Another biologically active compound with which the anti-inflammatory activity of aloe leaves may be associated with a pyrone derivative aloenin. At the same time, despite the widespread use in medicine and a well-studied chemical composition, the problems in the field of standardization of raw materials and preparations of Aloe arborescens are still urgent. The methods for determining the quantitative content of anthracene derivatives described in the literature are multistage, they provide for preliminary acid hydrolysis in combination with oxidation, liquid-liquid extraction of the formed aglycones and complexation with magnesium acetate. The approved regulatory documents for aloe raw materials and preparations does not provide for the assay of aloenin
 AIM: The aim is to develop the methods for determining the quantitative content of biologically active compounds in the raw materials and preparations of fresh leaves of Aloe arborescens by using the spectrophotometric method and the high-performance liquid chromatography method.
 MATERIALS AND METHODS: The objects of research were fresh leaves of Aloe arborescens Mill., and juice obtained ex tempore from fresh leaves of aloe. Samples of raw materials were collected in the summer and autumn of 2020 in the Winter Garden of the Department of Pharmacognosy with Botany and Bases of Phytotherapy at Samara State Medical University. Individual substances were isolated by column chromatography. In the study, the Bruker DRX 500 instrument (126.76 MHz) was used to determine 13C NMR spectra, and the Bruker AM 300 instrument (300 MHz) was used to determine 1H NMR spectra. Mass spectra were recorded on mass spectrometer Kratos MS-30, UV spectra were recorded by means of the spectrophotometer Specord 40 (Analytik Jena). High-performance liquid chromatography analysis was carried out with the use of the chromatograph Milichrom-6 (Nauchpribor, Russia).
 RESULTS: As a result of the study, aloenin and a mixture of aloins A and B (barbaloin) were isolated from the leaves of Aloe arborescens by with the use of column chromatography. The method for the determination of the quantitative content of aloenin by microcolumn reversed-phase high-performance liquid chromatography with UV detection (306 nm) was developed, the mobile phase was acetonitrile: 1% acetic acid solution in water in the ratio of 25:75, the elution rate is 100 L / min. The method for the quantitative determination of the total amount of anthracene derivatives in Aloe arborescens fresh leaves (differential spectrophotometry with an alkaline-ammonia solution at 412 nm) was developed. The optimal conditions for the extraction were selected. They are extractant of 40% ethyl alcohol, extraction within 60 minutes at the ratio of raw material extractant is 1:50. Validation analysis has shown that the developed methods are characterized by satisfactory metrological indicators.
 CONCLUSIONS: The obtained results can be used to update the pharmacopoeial monograph Aloe arborescens leaves fresh.

The effect of solvation on electron capture revealed using anion two-dimensional photoelectron spectroscopy.

The reaction of low-energy electrons with neutral molecules to form anions plays an important role in chemistry, being involved in, for example, various biological and astrochemical processes. However, key aspects of electron-molecule interactions, such as the effect of incremental solvation on the initially excited electronic resonances, remain poorly understood. Here two-dimensional photoelectron spectroscopy of anionic anthracene and nitrogen-substituted derivatives-solvated by up to five water molecules-reveals that for an incoming electron, resonances red-shift with increasing hydration; but for the anion, the excitation energies of the resonances remain essentially the same. These complementary points of view show that the observed onset of enhanced anion formation for a specific cluster size is mediated by a bound excited state of the anion. Our findings suggest that polycyclic aromatic hydrocarbons may be more efficient at electron capture than previously predicted with important consequences for the ionization fraction in dense molecular clouds.

Visible Light Induced Solubility Modulation of Polynorbornene Bearing Bridged 1,2‐Diketones

AbstractWe herein report the synthesis and photoinduced solubility modulation of a poly(norbornene) bearing bridged 1,2‐diketone units in the repeating unit. Selective irradiation of the n to π* absorption band of the monomer using a blue LED light source emitting at 455 nm lead to a rapid and quantitative decarbonylation at the diketone bridge, yielding the corresponding anthracene derivative. Identical photoinduced decarbonylation was observed in the polymer obtained from the ring‐opening metathesis polymerization (ROMP) of the photoreactive monomer. The polymer displayed photoinduced solubility change wherein irradiation of the polymer solution in various solvent systems with a blue LED light source led to the precipitation of the polymer, producing polymer nanoparticles. The solubility change is attributed to the change in the free volume of the polymer and constitutes a method of photoinduced solubility modulation in which only gaseous byproducts are generated from the photocleavage reaction.

Use of Partition Coefficients in a Hexane-Acetonitrile System in the GC-MS Analysis of Polyaromatic Hydrocarbons in the Example of Delayed Coking Gas Oils.

The partition coefficients’ application in the hexane–acetonitrile system as an additional identification feature of polyaromatic hydrocarbons in the review gas chromatography–mass spectrometry analysis of delayed coking gas oils has been considered. The UNIFAC model was used to calculate the partition coefficients of polycyclic aromatic hydrocarbons. It is shown that methyl derivatives of naphthalene, fluorene, anthracene, and pyrene can be identified with an accuracy up to several methyl groups by the position of the figurative point on the partition coefficient–retention index plane. The experimental values of partition coefficients for naphthalene, anthracene, and pyrene are 0.82, 0.78, and 0.77, respectively. The appearance of one methyl group increases the partition coefficient by 0.15–0.2 on average. A total of 53 polyaromatic hydrocarbons were identified in this way.

Unsubstituted and Methylated PAHs in Surface Sediment of Urban Rivers in the Red River Delta (Hanoi, Vietnam): Concentrations, Profiles, Sources, and Ecological Risk Assessment.

Unsubstituted and methylated polycyclic aromatic hydrocarbons (22 PAHs and 17 Me-PAHs) were examined in surface sediments collected from the Red River and four inner-city rivers of Hanoi City, Vietnam. Concentrations of total PAHs and Me-PAHs ranged from 52 to 920 (median 710) and from 70 to 2600 (median 1000) ng/g dry weight in samples of dry and wet seasons, respectively. Significant correlation was observed between total PAHs and organic carbon contents (Spearman's ρ = 0.782; p < 0.05). PAHs were more abundant than Me-PAHs in all samples and dominated by 4-6 ring compounds. The most predominant PAHs were benzo[ghi]perylene, benzo[b/j]fluoranthene, chrysene, pyrene, fluoranthene, and phenanthrene. Methylated derivatives of naphthalene, phenanthrene, anthracene, and benz[a]anthracene were frequently detected. The patterns of PAHs indicated principal pyrogenic sources (notably gasoline exhaust) in this highly urbanized area. The occurrence of several PAHs were occasionally associated with adverse effects on benthic organisms of the inner-city rivers.

Two novel thiophene derivatives based on chalcone skeleton:a systematic study of ultrafast nonlinear absorption and excited-state dynamics

Two thiophene derivatives(TH-17 and TH-19) were synthesized and the ultra-fast nonlinear optical (NLO) performance was investigated using z-scan technique. Both compounds exhibit NLO response of reverse saturated absorption(RSA) in wide wavelength range (560 nm–800 nm). Intrinsic multi-photon absorption is considered to cause performance. The mechanism of two-photon absorption(TPA) and TPA induced excited-state absorption (TPA-ESA) was introduced to explain the progress. Several primary nonlinear coefficients, including the two-photon absorption(TPA) coefficients and TPA cross section, were calculated. TH-19 displays superior NLO response than TH-17 at all wavelengths due to better electron delocalization and the TPA coefficient in 10−12(m/w) order of magnitude at 560 nm is obtained. The NLO performance is also better than several anthracene derivatives and chalcone derivatives with similar molecular structure reported recently. The substituted terminal thiophene is proved to improve the NLO properties due to the enhancement of π-electron delocalization. Moreover, the excited-state absorption was investigated via femtosecond transient absorption experiment. Intense excited-state absorption at the region of 550 nm–750 nm is observed according to the transient absorption(TA) spectrum. The kinetic processes are analyzed and four relaxation processes(TH-19) of 0.25 ps, 4.5 ps, 188ps and 2.43ns are obtained. The enhanced NLO response and changing region of excited-state absorption indicates the fine-tuned performance of NLO response via the change of terminal substituents.

Fabrication of stimulus-responsive molecular layer comprising anthracene molecules

For efficient control of surface properties of materials, the immobilization of functional molecules as a molecular layer is one effective method. Furthermore, stimulus-responsive molecules can provide a strong pathway to develop switchable surface properties. The reversible chemical bond change based on the cycloaddition reaction of anthracene is a useful method to change the outermost surface composition in the laminated molecular layer. Moreover, it exhibits a high degree of freedom in selecting the desired surface properties. Here, we have designed a stimulus-responsive molecular layer with an anthracene derivative for repeated control of surface properties. The switching of covalent bonding of anthracene induced by photodimerization and thermal/photocleavage reactions was introduced to control the composition of the molecular layer. The reversible reaction caused by photoirradiation or heating of the anthracene layer was demonstrated though absorption and fluorescence spectroscopy. In addition, the influence on the surface conditions such as contact angle and surface morphology was revealed. The stimulus-responsive surface functions of this material can potentially be applied to the fields of adhesion and friction.

Regulating Circularly Polarized Luminescence of Axially Chiral Anthracene Derivatives through Solvatochromism and Supramolecular Self‐assembly

AbstractTwo axially chiral fluorophores derived from anthracene were designed and synthesized, and the chiroptical behaviour were thoroughly investigated including solvent‐dependent emission and circularly polarized luminescence (CPL). Interestingly, unexpected supramolecular self‐assembly of the chiral molecules driven by strong π−π interaction can enable significant hypsochromic shift and fluorescence intensity enhancement. Meanwhile, the luminescence dissymmetry factor of CPL activity exhibited significant enhancement through self‐assembly process. This work provides a novel approach to achieve the supramolecular CPL materials possessing both high luminescence quantum efficiency and high circular polarization.

Drawing a parallel between phytochemistry and other features of Vismieae species

The present study provides an overview, focusing on the botanical aspects, phytochemistry, ethnopharmacology and biological activities reported for species from the tribe Vismieae (Hypericaceae). These species, traditionally distributed in three genera (Vismia, Psorospermum and Harungana), occur predominantly in tropical areas of South America, mainland Africa and Madagascar, where several of them are used in the traditional medicine mainly as febrifugal, antimalarial and for treating wounds of diverse origin. The phytochemical investigations indicated that the plants produce anthraquinones, anthrones, xanthones, benzophenones, flavonoids and some terpenoids. A number of 221 different compounds were obtained from 32 species of the tribe. Several compounds were investigated for the pharmacological activities, being cytotoxic and antimicrobial the most cited. Nevertheless, a number of pharmacological researches were carried out with extracts and some findings experimentally evidenced the ethnopharmacological usefulness of several species. The distribution of the anthracenic derivatives, xanthones and benzophenone precursors is not uniform in the genera. Thus, the substitution pattern of these compounds was analyzed and the systematic relationship among the taxa is discussed in the light of these features. Of note, more species need chemical investigation in order to make a judgment about the taxonomic significance of the compounds, but it seems that, although the tribe has a certain homogeneity, each genus has particularities. Considering this statement, it is possible to say that in the chemical point of view, Psorospermum is diferent from Harungana and both are diferent from Vismia, which is clearly separate into two distinct groups, the African and the American species.

Allelopathic potential and phytochemical screening of Piper divaricatum extracts on germination and growth of indicator plant (Lactuca sativa)

Weeds are one of the most damaging crop pests with estimated annual global damage of around U$ 40 billion. About four million tonnes of pesticide are applied to crops worldwide each year. Currently, there is a growing demand for the use of natural products in agriculture in order to ensure the health of plants and environment. This trend has stimulated research on biodefensives from plant origin. Here, the phytotoxicity of organic extracts and fractions from Piper divaricatum leaves was evaluated on inhibition of emergence and initial growth in lettuce (Lactuca sativa) seedlings. Bioassays were carried out in chamber growth and the detection of compounds classes was performed by Thin Layer Chromatography. Hexane extract completely inhibited emergence and seedling growth at 7.5 and 10.0 mg/mL. Ethanol/methanol extract was highly toxic to seedlings in all concentrations, displaying 100% of inhibition on emergence. Aqueous and alcoholic extracts were submitted to partition and fractions assayed at 2.5 mg/mL. Chloroform fraction of aqueous extract displayed a higher inhibition rate on emergence (100%), however, the fractions obtained from Ethanol/Methanol extract displayed a range of inhibition rate from 33 to 71%, which drastically affected the root and seedling growth. Phytochemical screening using thin layer chromatography combined with chemical revelators was applied. Alkaloids and coumarins were found in chloroform fraction of aqueous extract, both reported as potent inhibitors of emergence, causing changes in cell division, tissue damage, and interfering in cellular transport. Other compounds such as fatty acids and anthracene derivatives were also found in Methanol/Ethanol extract fractions and are reporting for the first time as potential allelochemicals in P. divaricatum.