Yellow Needles Research Articles

Crystal structures of the (η2:η2-cyclo-octa-1,5-diene)(η6-toluene)-iridium(I) cation and μ-chlorido-iridium(III) complexes of 2-(phosphinito)- and 2-(phosphinometh-yl)anthra-quinone ligands.

When reacted in dry, degassed toluene, [Ir(COD)Cl]2 (COD = cyclo-octa-1,5-diene) and 2 equivalents of 2-(di-tert-butyl-phosphinito)anthra-quinone (tBuPOAQH) were found to form a unique tri-iridium compound consisting of one monoanionic dinuclear tri-μ-chlorido complex bearing one bidentate tBuPOAQ ligand per iridium, which was charge-balanced by an outer sphere [Ir(toluene)(COD)]+ ion, the structure of which has not previously been reported. This product, which is a toluene solvate, namely, (η2:η2-cyclo-octa-1,5-diene)(η6-toluene)-iridium(I) tri-μ-chlorido-bis-({3-[(di-tert-butyl-phosphan-yl)-oxy]-9,10-dioxoanthracen-2-yl}hydridoiridium(III)) toluene monosolvate, [Ir(C7H8)(C8H12)][Ir2H2(C22H24O3P)2Cl3]·C7H8 or [Ir(toluene)(COD)][Ir(κ-P,C-tBuPOAQ)(H)]2(μ-Cl)3]·toluene, formed as small orange platelets at room temperature, crystallizing in the triclinic space group P. The cation and anion are linked via weak C-H⋯O inter-actions. The stronger inter-molecular attractions are likely the offset parallel π-π inter-actions, which occur between the toluene ligands of pairs of inverted cations and between pairs of inverted anthra-quinone moieties, the latter of which are capped by toluene solvate mol-ecules, making for π-stacks of four mol-ecules each. The related ligand, 2-(di-tert-butyl-phosphinometh-yl)-anthra-quinone (tBuPCAQH), did not form crystals suitable for X-ray diffraction under analogous reaction conditions. However, when the reaction was conducted in chloro-form, yellow needles readily formed following addition of 1 atm of carbon monoxide. Diffraction studies revealed a neutral, dinuclear, di-μ-chlorido complex, di-μ-chlorido-bis-(carbon-yl{3-[(di-tert-butyl-phosphan-yl)-oxy]-9,10-dioxoanthracen-2-yl}hydridoiridium(I)), [Ir2H2(C23H26O2P)2Cl2(CO)2] or [Ir(κ-P,C-tBuPCAQ)(H)(CO)(μ-Cl)]2, Ir2C48H54Cl2O6P2, again crystallizing in space group P. Offset parallel π-π inter-actions between anthra-quinone groups of adjacent mol-ecules link the mol-ecules in one dimension.

Cytotoxic of Usnic Acid Isolated from Ramalina sp.

Ramalina sp. (Ramalinaceae) is a type of lichen known to contain many active secondary metabolite compounds that have the potential to be used as medicine or medicinal raw materials. One of the biological activities possessed by Ramalina sp. lichen is its anticancer activity. This research aims to isolate and identify active secondary metabolite compounds from the methanol extract of the Ramalina sp. lichen and to find out the cytotoxic activity of the isolated compound against MCF7 breast cancer cells. Compound 1 (usnic acid) was successfully isolated from fraction A. The isolation and purification process was carried out starting with a maceration process using acetone solvent, followed by silica gel column chromatography using a gradient solvent system consisting of n-hexane, n-hexane: EtOAc, EtOAc, EtOAc: MeOH, and MeOH with 5% increment of polarity to obtain 17 fractions (F-1 to F-17). From the 17 fractions obtained, fraction 3 (F-3) and fraction 4 (F-4) (eluted with n-hexane: EtOAc 30%), which had the same TLC profile, were combined and named as fraction A. Compound 1 (50 mg) is a yellow needle crystal that was formed in a bottle of fraction A, which was obtained after the process of combining fractions F-3 and F-4 and solvent evaporation process. The crystals were then separated and purified with CHCl3 and MeOH. Compound 1 was then characterized based on spectroscopic data. Various spectroscopic analysis data, including FTIR, 1D- and 2D-NMR, and LC-ESI-MS, show that Compound 1 is a dibenzofuran derivative compound with 18 carbons (3 from carbonyl groups (C=O) and 3 from methyl groups) and 2 hydroxyls (-OH). Cytotoxicity assay showed that at a low concentration of 18.75 ug/mL, Com-pound 1 caused a 67.06% decrease in MCF7 viability.

Comprehensive Proteome and Acetylome Analysis of Needle Senescence in Larix gmelinii.

Leaf senescence is essential for the growth and development of deciduous trees in the next season. Larix gmelinii, a deciduous coniferous tree, exhibits its most distinctive feature by turning yellow in the autumn and eventually shedding its leaves, resulting in significant changes in its appearance during the fall. Lysine acetylation plays an important role in diverse cellular processes; however, limited knowledge is available regarding acetylations in the needle senescence of L. gmelinii. In this study, the proteomics and acetylated modification omics of two phenotypic leaves, yellow and green (senescent and non-senescent) needles, were analyzed before autumn defoliation. In total, 5022 proteins and 4469 unique acetylation sites in 2414 lysine acylated proteins were identified, and this resulted in the discovery of 1335 differentially expressed proteins (DEPs) and 605 differentially expressed acetylated proteins (DAPs) in yellow versus green needles. There are significant differences between the proteome and acetylome; only 269 proteins were found to be DEP and DAP, of which 136 proteins were consistently expressed in both the DEP and DAP, 91 proteins were upregulated, and 45 proteins were down-regulated. The DEPs participate in the metabolism of starch and sucrose, while the DAPs are involved in glycolysis and the tricarboxylic acid cycle. Among them, DEPs underwent significant changes in glycolysis and citric acid cycling. Most of the enzymes involved in glycolysis and the citrate cycle were acetylated. DAPs were down-regulated in glycolysis and up-regulated in the citrate cycle. In all, the results of this study reveal the important role of lysine acetylation in the senescence of L. gmelinii needles and provide a new perspective for understanding the molecular mechanism of leaf senescence and tree seasonal growth.

Особенности накопления минеральных элементов и азота в ассимиляционном аппарате сосны обыкновенной

The research has been carried out in the Arkhangelsk forestry of the Arkhangelsk Region in a drained shrub-sphagnum pine forest. Census trees of medium diameter and height for the stand have been selected, from which samples of needles, both living and dying yellow ones, and shoots of different ages have been taken on model branches. Soil samples have also been taken from the 3 upper horizons. It has been established that most of all nitrogen and mineral elements accumulate in the living needles – 4.4 % on average, in the dying needles and shoots there are 37–40 % less. Among all the elements, nitrogen, potassium and calcium make up the largest proportion; while the rest of the chemical elements are several time less. In descending order of the share, they are arranged in the following sequence: magnesium, sulfur, phosphorus, manganese, silicon, iron and aluminum. The most important mineral elements are derived in significant quantities from the dying yellow needles. The content of sulfur, magnesium, phosphorus, manganese and iron decreases in them by 3.3, 2.1, 8.0, 1.5 and 1.4 times, respectively, compared to the living needles. Data on the presence of nitrogen and mineral elements in the soil horizons A0, T1 and T2 have been obtained. It has been established that some of the essential elements for the life of a tree are concentrated in the living needles in much larger quantities than in the soil: potassium, phosphorus, manganese and calcium – by 12.0, 4.0, 6.0 and 1.9, respectively. The yellow falling needles create a biological cycle of substances. The amount of nitrogen and ash constituents in these needles is proportional to their presence in the soil. In turn, the content of mineral elements in the shoots is close to their amount in the yellow falling needles, on the one hand, and on the other, depends on the age of the shoots. There is a steady trend of decreasing the content of nitrogen, potassium, phosphorus and sulfur with the age of the shoots.

“Cutting effect” of needles on the raindrop characteristics

Plant leaves (both in the canopy and on the land surface) can substantially alter raindrop characteristics, which link to rainfall evaporation, infiltration, raindrop energy, and land surface erosion. The effect varies depending on the leaf morphology. Because of the magnitude difference between needle diameter (∼1 mm) and raindrops (up to ∼8 mm), there should be a “cutting effect” of the needle on falling raindrops. However, no study has beem performed to address how this effect alters raindrop characteristics. In this study, we investigated the effect using artificial water drops, high-speed photography, and staining method in the laboratory. Masson pine (Pinus massoniana Lamb.) needles were collected from the field including fresh green needles (FGN) withered yellow needles (WYN) partially decomposed needles (PDN). The needle properties (i.e., surface repellency, cross-section morphology, and flexural stiffness) were measured to determine the factor controlling the cutting effect. Results showed that after the cutting effect, one raindrop could be cut into up to 12 small raindrops. Their velocities owned a bimodal distribution. Compared to the diameter before the cutting effect occurred, the raindrop diameter decreased by an average of 59 %, and the raindrop velocity decreased by an average of 19 %. This caused a substantial decrease in the raindrop energy (∼85 %). The cutting effect included three sub-processes: collision, splitting, and interception. Our analysis suggested that the splitting process was the main reason for the cutting effect to reduce raindrop energy. The cutting effect was affected by the needle properties and raindrop falling heights. The cutting effect was enhanced when the needle developed from FGN and WYN to PDN. The cutting effect was positively related to the falling height of raindrops. Changes in the raindrop characteristics due to the cutting effect should enhance rainfall evaporation and infiltration and thus decrease soil erosion, which needs to be evaluated in further studies.

First report of 'Candidatus Phytoplasma asteris' associated with witches'-broom disease of Pinus yunnanensis in China.

Pinus yunnanensis is an evergreen tree belonging to Pinaceae. The species is distributed in the east of Tibet, southwest of Sichuan, southwest of Yunnan, southwest of Guizhou and northwest of Guangxi. It is an indigenous and pioneer tree species for barren mountain afforestation in southwest China. P. yunnanensis has important value to both the building and medicine industries (Liu et al. 2022). In May 2022, P. yunnanensis showing witches'-broom symptom were found in Panzhihua City, Sichuan Province, China. The symptomatic plants had yellow or red needle, and exhibited plexus bud and needle wither. The lateral buds of infected pines developed into twigs. Some lateral buds grew in clusters and a few sprouted needles (Fig.1). The disease was named the P. yunnanensis witches'-broom disease (PYWB) and was found in some areas of Miyi, Renhe, and Dongqu. More than 9% of the pines showed these symptoms in the three areas surveyed, and the disease was spreading. A total of 39 samples were collected from three areas, including 25 symptomatic plants and 14 asymptomatic plants, respectively. The lateral stem tissues of 18 samples were observed under a scanning electron microscope (Hitachi S-3000N). Spherical bodies were found in the phloem sieve cells of symptomatic pines (Fig.1). Total DNA was extracted from 18 plant samples using the CTAB method (Porebski et al. 1997) and subjected to nested-PCR testing. Double-distilled water and DNA extracted from asymptomatic plants were used as negative controls, and DNA extracted from Dodonaea viscosa affected by the D. viscosa witches'-broom disease was used as positive control. Nested PCR was employed to amplify the pathogen's 16S rRNA gene (Lee et al. 1993; Schneider et al. 1993) and 1.2 kb segment were produced (GenBank accessions OP646619; OP646620; OP646621). PCR specific to the ribosomal protein (rp) gene yielded segment of approximately 1.2 kb (Lee et al. 2003)(GenBank accessions OP649589; OP649590; OP649591). The fragment size from 15 samples was consistent with the positive control, confirming the association of phytoplasma with the disease. A BLAST analysis of the 16S rRNA sequences of P. yunnanensis witches'-broom phytoplasma showed that it shared 99.12% ~99.76% identity with that of Trema laevigata witches'-broom phytoplasma (GenBank accession MG755412). The rp sequence shared 99.84%~99.92% identity with that of Cinnamomum camphora witches'-broom phytoplasma (GenBank accession OP649594). An analysis with iPhyClassifier (Zhao et. 2013) showed that the virtual RFLP pattern derived from OP646621 16S rDNA fragment of PYWB phytoplasma is identical (similarity coefficient 1.00) to the reference pattern of 16Sr group I, subgroup B (OY-M, GenBank accession AP006628). The phytoplasma is identified as a 'Candidatus Phytoplasma asteris'-related strain belonging to sub-group 16SrI-B. Interestingly, compared to AP006628, the virtual RFLP pattern derived from OP646619 and OP646620 fragments exhibit differences in three and one cleavage site, with a similarity coefficient of 0.92 and 0.97, respectively (Fig.2). These strains may represent a new subgroup within the 16Sr group I. The phylogenetic tree was reconstructed based on 16S rRNA and rp gene sequences using MEGA versio6.0 (Tamura et al. 2013). The analysis was conducted using the neighbor-joining (NJ) method with 1,000 replicates of bootstrap analysis. The results indicated that the PYWB phytoplasmas grouped into clades including phytoplasmas belonging to 16SrI-B and rpI-B, respectively (Fig.3). In addition, 2-year-old P. yunnanensis were used for grafting assays in nursery, and the twigs from infected pine under natural conditions were used as a scion, and the phytoplasma were detected using nested PCR after grafting for 40 d (Fig.4). In 2008-2014, P. sylvestris and P. mugo in Lituania had excessive branching symptoms that were attributed to 'Ca. Phtyoplasma Pini' (16SrXXI-A) or asteris' (16SrI-A) strains (Valiunas et al. 2015). In 2015, P. pungens with abnormal shoot branching in Maryland were found to be infected by 'Ca. Phytoplasma pini' strain (16SrXXI-B) (Costanzo et al. 2016). To the best of our knowledge, P. yunnanensis is a new host of 'Ca. Phytoplasma asteris'-related strain (16SrI-B) in China. The newly emerged disease is a threat to pines.

Изменчивость биохимических признаков Pinus sylvestris (Pinaceae) при адаптации форм в условиях избыточного увлажнения

Conifers are characterized by a certain degree of individual variability in the content of stress metabolites, which can be caused by genotypic variations or divergence in the growth conditions of individual trees. The purpose of the study is to evaluate the variation of biochemical traits of Scots pine, which are different in the color of male strobilus, during adaptation to the conditions of constant excessive moisture in the soil of the northern taiga. The dynamics of metabolic parameters of Pinus sylvestris L. were investigated in shrubsphagnum pine stands on marshy upland soils at the mouth of the Northern Dvina River (northern taiga subzone). From July to November 2018, needle samples from shoots were collected from 10 pine trees of each of the male strobilus types, differentiated by color. The contents of photosynthetic pigments, anthocyanins, ascorbic acid, proline, water-soluble proteins, and pH were measured under laboratory conditions. The synthesis of chlorophyll in the needles in the current year of formation decreased in trees of both forms during the dry summer period. A favorable temperature in the autumn period could promote an extension of photosynthetic pigment accumulation, which might negatively affect tree preparation for overwintering. There were no significant differences between f. erythranthera Sanio and f. sulfuranthera Kozubow in the needle content of chlorophyll and carotenoids, anthocyanins, ascorbic acid, free proline, water-soluble proteins, or pH. The similarities in the adaptation of the trees to the constant excessive soil moisture in northern taiga conditions were revealed. The seasonal factor had a considerable impact on the dynamics of biochemical parameters. Ascorbic acid, proline, and anthocyanin were more actively accumulated in the needles throughout the summer due to the high air temperature, resulting in an increase in antioxidant activity and the development of protective mechanisms aimed at reducing oxidative stress. The increase in water-soluble protein content in needles from October to November is one of the cryoprotective mechanisms of the trees for the winter period. Individual differences in ascorbic acid and proline contents in yellow microspore-bearing pine needles at the establishment of minus temperatures in November were considerably higher than in red microspore-bearing pine needles. This is regarded as the norm of the reaction for different types of trees to the influence of negative temperatures. For citation: Tarkhanov S.N., Pinaevskaya E.A., Aganina Y.E., Pakhov A.S. Variability of Biochemical Properties During Adaptation of Pinus sylvestris (Pinaceae) Forms to Excessive Moisture Conditions. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 4, pp. 58–75. (In Russ.). https://doi.org/10.37482/0536-1036-2023-4-58-75

Xanthoangelol, geranilated chalcone compound, isolation from pudau leaves (Artocarpus kemando Miq.) as antibacterial and anticancer

Abstract From the leaves of Artocarpus kemando Miq, locally known as pudau plant, a flavonoid has been isolated and identified. The compound was then tested as antibacterial agent against Bacillus subtillis and Escherichia coli. The first step of isolation was extraction by maceration using methanol as solvent, and then followed by fractionation using partition treatment and vacuum liquid chromatography. Finally, the compound was purified using column chromatography method. The purity of the compound was evaluated using thin layer chromatography and melting point measurement, and the compound was subsequently characterized using UV–Vis, IR, and NMR spectroscopy. A total of 66.2 mg of the compound was obtained, in the form of yellow needle crystals with a melting point of 142.8–144 °C, which is a compound of geranylated chalcone, xanthoangelol. Xanthoangelol was the first chalcone compound isolated from A. kemando. Antibacterial tests were carried out at varied doses of 0.5; 0.4; and 0.3 mg/disk, and revealed that the compound exhibits high inhibitory power against B. subtillis, but has no activity against E. coli. The anticancer activity of xanthoangelol on MCF-7 cells indicated that the compound has an IC50 value of 7.79 μg/mL, suggesting that the compound possesses an active cytotoxic activity.

Potential of Usnic Acid Compound from Lichen Genus Usnea sp. as Antidiabetic Agents.

Lichen Usnea sp. is potential as a new natural medicine. This study report isolation of secondary metabolites from lichen Usnea sp. and α-glucosidase inhibitory, which is potential as an antidiabetic agent. Lichen powder was macerated using methanol, separated using column chromatography gravity and thin-layer chromatography. The crystalline was isolated and purified by the recrystallization process for obtaining pure compound. The isolated compound was determined using FTIR and NMR spectroscopy (1H and 13C). The results showed that the isolated compound was yellow needle crystals. Based on the spectra data interpretation, it was obtained usnic acid compound with the molecular formula of C18H16O7. The α-glucosidase inhibitory activity test showed that the usnic acid had activity in inhibiting the α-glucosidase enzyme with an IC50 value of 106.78 µg/mL. The usnic acid from Usnea sp. has a very good impact on the source of natural compounds as an antidiabetic drug in the future.

Isolation of isoeleutherol from microwave assisted methanol extract of Eleutherine bulbosa bulbs, its crystal structure elucidation and cytotoxicity evaluation

Different extraction methods (Soxhlet, Serial soxhlet, Cold, and microwave-assisted extraction) were executed for the extraction of phytochemicals from the bulbs of Eleutherine bulbosa Miller (Urban), an important medicinal plant in the family Iridaceae. Among the different methods, most efficient (especially in terms of extraction time) was the microwave-assisted extraction (MAE) using methanol as the extraction solvent. The microwave assisted methanolic extract was subjected to column chromatography and a naphthalene compound, isoeleutherol was isolated. Starting from, about two grams of the crude methanol extract, 21 mg of pure compound (isoeleutherol) was obtained as yellow needle like crystals with an Rf value of 0.53 in TLC. The structural characterization was done by Single crystal X-ray diffraction analysis. The study also tested the cytotoxic activity of the compound against two cancer cell lines (HeLa and MCF-7) and one normal cell (Chang liver cells) line by MTT assay. Results of the cytotoxicity evaluation showed that isoeleutherol has potent activity on both the cancer cell lines with LC 50 values of 35.4 and 23.8 μg/ml against HeLa and MCF-7 cells, respectively. Isoeleutherol exhibitted less cytotoxicity towards normal cells (Chang liver cells). At the highest concentration used (100 μg/ml), 60.99 ± 1.92% normal cells were viable. This is the first report of isolation of a compound from E. bulbosa through microwave-assisted extraction, a faster and environment friendly technique for the phytochemical extraction. The present study also reports detailed structural elucidation of isoeleutherol by X-ray crystallography for the first time.

Углеводороды и сложные эфиры экстрактивных веществ хвои лиственницы сибирской

Siberian larch (Larix sibirica L.) is the main commercial species in Russia. Currently, larch woody greens are underutilized. They are considered a waste product from logging. This is due to the lack of knowledge on the composition of compounds and the variability of the raw material source itself as a result of the fall of the needles. The research purpose is to study the composition of hydrocarbons and esters from Siberian larch needles in summer and autumn collection from the Tomsk region. The shredded needles were extracted with propan-2-ol; then, after distillation of the solvent, substances soluble in petroleum ether (PE, 40–70 °С) were isolated. The latter were divided into free acids (31.5 % for green needles and 28.0 % for yellow needles) and neutral substances (59.8 and 48.1 %, respectively). Then, eutral substances were chromatographed on silica gel: hydrocarbons (2.43 and 3.02 %, hereinafter from neutral substances of green and yellow needles, respectively), esters (31.30 and 33.80 %) and triglycerides (11.70 % and 6.44 %). The ester and triglyceride fractions were exposed to alkaline hydrolysis and the acidic components of esters (9.12 and 24.80 %) and triacylglycerols (17.43 and 26.15 %) were produced. Fractions of unsaponifiable compounds, in addition to alcohols, contained unsaponifiables with unchanged Rf values on thin-layer chromatography (TLC). Fractions of unsaponifiables were chromatographed on silica gel, and then the isolated fractions were additionally chromatographed on silica gel with silver nitrate. The isolated compounds were identified by nuclear magnetic resonance (NMR) spectroscopy. In the acidic component of esters, the main components are linoleic and linolenic acids. Hydrocarbons are represented by sesquiterpenes in both collections of needles. A new aromatic hydrocarbon for coniferous plants, geranyl-p-cymene, has been identified. For the first time, polyprenols were isolated from Siberian larch greens, the structure of which differs from spruce and pine polyprenols by chain length according to NMR spectroscopy and mass spectrometry data. They contain from 14 to 20 isoprene links in the chain of molecules with predominance of prenol-17. The yield of polyprenols was 12.8–14.9 % of neutral substances of yellow and green needles, respectively. Tetracyclic triterpene alcohols and sterols were isolated from green needles. Triterpene alcohols were not found in yellow needles. For citation: Mikson D.S., Roshchin V.I. Hydrocarbons and Ethers of Extractive Substances of Siberian Larch Needles. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 3, pp. 170–185. DOI: 10.37482/0536-1036-2021-3-170-185

Identification and antibacterial activity of flavonoid compounds from wood branches of the pudau plant (Artocarpus kemando Miq.)

In this research, isolation, identification, and antibacterial assay of flavonoid compounds have been carried out. These compounds were obtained from the wood branches of the pudau endemic plant from Karang Anyar village, Penengahan, South Lampung Regency, Lampung Province. Flavonoid compound extraction was carried out by maceration method using methanol, while fractionation and purification were conducted using chromatography technique. The purity of the compounds was determined by the melting point test and thin layer chromatography, the identification of compounds was assigned by UV-Vis and IR spectroscopy. The results of the isolation obtained two compounds, artocarpin (1) and cycloartocarpin (2). Compound (1), 92 mg, in the form of a yellow needle crystal with a melting point of 184.9 -187.5 °C; compound (2), 20 mg, in the form of yellowish white needle crystals with melting point 280 - 283 °C. In the antibacterial assay against Bacillus subtilis and Escherichia coli, compounds (1) showed very strong antibacterial activity at a concentration of 0.4 mg/disk and 0.5 mg/disk, respectively, whereas compound (2) had strong antibacterial activity against B. subtilis and E. coli at the same concentration of 0.5 mg/disk.

Identification of Phenyl Propanoid Compound Isolated from Root Bark Datuan(Ficus vasculosa Wall. Ex Miq) and Antibacterial Activity Test on Escherichia coli

The purpose of this research was to identify phenyl propanoid compounds found in the root bark of Datuan (Ficus vasculosa Wall. Ex Miq) and to test the activity of Escherichia coli. Isolation was carried out by maceration method using methanol as a solvent. Then the extract was fractionated by Vacuum Liquid Chromatography and Gravity Column Chromatography methods using n-hexane, ethyl acetate, and methanol eluents. The result was obtained a yellow crystal needle orange weighing 20 mg with a melting point of 137°C - 140°C. Separation by TLC method showed that this compound had an Rf value of 0.56 with n-hexane: acetone eluent (6: 4). UV-Vis spectra showed three peaks on 310 nm, 228 nm and 200 nm. IR spectra showed that the isolated compound has unsaturated ester carbonyl groups conjugated with double bonds, aromatic substituted aromatic rings, and hydroxy groups. GC-MS analysis obtained molecular ions M+ = 178. The data of UV-Vis, IR and GC-MS analysis can be concluded that the isolated phenyl propanoid compound is a cinnamic derivative that is methyl p-hydroxycinamic. The results of bioactivity tests on E. Coli showed that the isolated compounds did not have antibacterial activity which was marked by the absence of a clear zone around the paper disk.

Role of Anions and Mixtures of Anions on the Thermochromism, Vapochromism, and Polymorph Formation of Luminescent Crystals of a Single Cation, [(C6H11NC)2Au

Noncoordinating anions, which generally play a subordinate role in coordination chemistry, alter the structure, the luminescence, as well as the thermochromic and vapochromic behaviors of salts of the two-coordinate cation, [(C6H11NC)2Au]+. Thus whereas the yellow polymorphs of [(C6H11NC)2Au](PF6) and [(C6H11NC)2Au](AsF6) contain single chains of cations and are vapochromic, yellow [(C6H11NC)2Au](SbF6) does not form the same polymorph and is not vapochromic but contains two distinct chains of cations connected through aurophilic interactions. Mixed crystals such as [(C6H11NC)2Au](PF6)0.50(AsF6)0.50 have been prepared by adding diethyl ether to a dichloromethane solution containing equimolar amounts of [(C6H11NC)2Au](PF6) and [(C6H11NC)2Au](AsF6). The initial (kinetic) product for the three combinations of anions ((PF6)-/(AsF6)-, (PF6)-/(SbF6)-, and (AsF6)-/(SbF6)-) was a precipitate of fine yellow needles with a green emission, which were gradually transformed at rates that depended on the anions present into colorless crystals with a blue emission. Whereas neither polymorph of [(C6H11NC)2Au](PF6) nor [(C6H11NC)2Au](SbF6) is thermochromic, the colorless mixed crystal [(C6H11NC)2Au](PF6)0.50(SbF6)0.50 is thermochromic and converts from blue-emitting to green-emitting at 87-95 °C. The temperature required to transform a crystal of the type [(C6H11NC)2Au](PF6)n(AsF6)1-n from colorless (blue-emitting) to yellow (green-emitting) increases as the fraction of hexafluorophosphate ion in the crystal increases. The yellow crystals of [(C6H11NC)2Au](PF6)0.75(AsF6)0.25, [(C6H11NC)2Au](PF6)0.50(AsF6)0.50, and [(C6H11NC)2Au](PF6)0.25(AsF6)0.75 are vapochromic, whereas the yellow crystals of [(C6H11NC)2Au](PF6)0.50(SbF6)0.50 and [(C6H11NC)2Au](AsF6)0.50(SbF6)0.50 are not.

THE SIBERIAN LARCH GROUP COMPOSITION AND ACID NEEDLES AT DIFFERENT VEGETATION PERIODS

The research results of the Siberian larch needle extractives are presented in paper. The content of extractive substances from green and yellow needles extracted by organic solvents with different polarities is determined. It is found out that the double increase of the yellow needle extractive substances content soluble in hydrocarbon extractant is observed, whereas it is decreased by 30 per cent when extracted with propan-2-ol. The group composition of needle extracts derived from isopropanol extract by petroleum ether is determined. The neutral substances content in both needle collections is practically the same, although the yellow needles contain less acid “bound” in the form of esters. There is a high content of waxes in the needles, which mainly consist of secondary nonacosanol-10 alcohol.
 The composition of free and “bound” acids in Siberian larch needles of different vegetation periods is established. The needles are dominated by groups of higher unsaturated C-18 fatty acids. Resin acids are represented by isopimaric acid (isopimaric and sandaracopimaric) and abietic acids: abietic, dehydroabietic and levopiric acids. In yellow needles, the content of dehydroabietic acid is increased quadrupled and the hydroxy acids are identified: 15-hydroxyabietic acid and 15-hydroxyhydroabietic acid. The tri- and tetraenic C-20 acids are identified among higher fatty acids.

Polymorph Selection of ROY by Flow-Driven Crystallization

The selection of polymorphs of the organic compound 5-methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrile, ROY, is studied experimentally in the confined space between two horizontal glass plates when an acetone solution of ROY of variable concentration is injected at a variable flow rate into water. Depending on the local concentration within the radial flow, a polymorph selection is observed such that red prisms are favored close to the injection center while yellow needles are the preferred polymorph close to the edge of the injected ROY domain. At larger flow rates, a buoyancy-driven instability induces stripes at the outer edge of the displacement pattern, in which specific polymorphs are seen to crystallize. Our results evidence the possibility of a selection of ROY polymorph structures in out-of-equilibrium flow conditions.

5,5′-Thiobis(3-methoxy-4H-1,2,6-thiadiazin-4-one)

The reaction of 3-chloro-5-methoxy-4H-1,2,6-thiadiazin-4-one (9) with Na2S·9H2O (0.5 equiv) in tetrahydrofuran (THF) at ca. 20 °C for 20 h gives 5,5′-thiobis(3-methoxy-4H-1,2,6-thiadiazin-4-one) (10) in a 44% yield as yellow needles. The compound was fully characterized.

Synthesis of 2-methyl-5-methoxy-1,4-benzoquinone and In-silico Activity Profiling Toward Cytochrome P450-3A4

The synthesis of 2-methyl-5-methoxy-1,4-benzoquinone (2) was carried out by reflux of 2-methyl-1,4-benzoquinone (1) with MeOH and ZnCl2 for 12 hours at ambient. The reaction resulted a yellow needle crystal in 6.92 % yield (m.p 173-175°C). The FT-IR analysis showed the presence of -OCH3 group at 1210 cm−1. The analysis using 1H-NMR showed chemical shift a δ = 3.81 ppm and the 13C-NMR gave 56.38 ppm for hydrogen and carbon from -OCH3 group. The bioavailability tests were determined by using in silico approach included lipophilicity (log P) and half maximum inhibitory concentration (IC50). It showed that the lipophilicity of 2 (log P = 0.92) is lower than 1 (log P = 1.79) which is calculated using Hyperchem software. The molecular docking of 2 towards cytochrome P450-3A4 showed a good result with IC50 13.68 ppm better than 1 (IC50 65.617 ppm). Further experimental is proposed for bromoalkylation of 2 using bromooctanoic acid to give 3-(7-bromoheptyl)-2-methyl-5-methoxy-1,4-benzoquinone (3). The in-silico calculation of 3 showed better lipophilicity (log P = 3.64) and IC50 (9.725 ppm) compared to 2. This result indicated that the addition of methoxyl and bromoalkyl group can improve the activity of the compound as a drug candidate.

Synthesis of N-methyl-4-piperidone Curcumin Analogues and Their Cytotoxicity Activity against T47D Cell Lines

Three piperidone curcumin analogues (N-methyl-(3E,5E)-3,5-bis-(2-chlorobenzylidene)-4-piperidone (1), N-methyl-(3E,5E)-3,5-bis-(3-bromobenzylidene)-4-piperidone (2) and N-methyl-(3E,5E)-3,5-bis-(4-chlorobenzylidene)-4-piperidone (3)) were synthesized from N-methyl-4-piperidone with halogenbenzaldehyde, 2-chlorobenzaldehyde, 3-bromobenzaldehyde and 4-chlorobenzaldehyde. The Claisen-Schmidt condensation reaction was used in alkali condition with combinatorial. All the compounds showed light yellow needle, light yellow powder, and yellow crystal form with percentage of yield 39, 66, and 40%, respectively. All the structure compounds were confirmed by using UV, IR, 13C-NMR, 1H-NMR and MS. Apart from that, the cytotoxicity results against breast cancer cell (T47D) showed strong to moderate activity with the IC50 value 8, 4, and 45 µg/mL, respectively.

A Flavanoid Compound Isolated From The Dichloromethane Extract Of The Silver Fern (Pityrogramma Calomelanos)

A flavanoid compound, namely 2’,6’-dihydroxy-4’-methoxydihydrochalcone had been separated from the dichloromethane extract of the silver fern (Pityrogramma calomelanos). It was obtained as pale yellow needles crystal with m.p. of 167 – 168 °C. Its structure was identified based on the spectroscopic evidence and by comparison with reported literature data.