Self-Assembled Corn-Husk-Shaped Fullerene Crystals as Excellent Acid Vapor Sensors

Low-molecular-weight acid vapors cause aging and destruction in material processing. In this paper, facile fabrication of novel corn-husk-shaped fullerene C60 crystals (CHFCs) through the dynamic liquid–liquid interfacial precipitation method is reported. The CHFCs were grown at the liquid–liquid interface between isopropyl alcohol (IPA) and a saturated solution of C60 in mesitylene under ambient temperature and pressure conditions. The average length, outer diameter, and inner diameter of CHFCs were ca. 2.88 μm, 672 nm, and 473 nm, respectively. X-ray diffraction (XRD) analysis showed the CHFCs exhibit a mixed face-centered cubic (fcc) and hexagonal-close pack (hcp) crystal phases with lattice parameters a = 1.425 nm, V = 2.899 nm3 for fcc phase and a = 2.182 nm, c = 0.936 nm, a/c ratio = 2.33, and V = 3.859 nm3 for hcp phase. The CHFCs possess mesoporous structure as confirmed by transmission electron microscopy (TEM) and nitrogen sorption analysis. The specific surface area and the pore volume were ca. 57.3 m2 g−1 and 0.149 cm3 g−1, respectively, are higher than the nonporous pristine fullerene C60. Quartz crystal microbalance (QCM) sensing results show the excellent sensing performance CHFCs sensitive to acetic acid vapors due to the enhanced diffusion via mesoporous architecture and hollow structure of the CHFCs, demonstrating the potential of the material for the development of a new sensor system for aliphatic acid vapors sensing.

SYNTHESIS OF COCRYSTALS OF BETULIN WITH SUBERIC ACID AND STUDY OF THEIR PROPERTIES

Lupane triterpenoids, betulin and its derivatives, are attracting great interest due to their wide range of biological and pharmacological activities. However, the poor solubility of betulin and its derivatives in aqueous media significantly reduces their bioavailability. Obtaining cocrystals, that is, multicomponent crystal systems containing active pharmaceutical ingredients and non-toxic partner molecules in their structure, is used in pharmacy to change the physicochemical properties of drugs, including the rate of dissolution and solubility. In this study, cocrystals of betulin with suberic acid were obtained by liquid-assisted grinding method using organic solvents of different polarity: ethanol, acetone, ethyl acetate, chloroform, toluene, dioxane. The formation of cocrystals was confirmed by X-ray diffraction analysis, IR spectroscopy, and thermal analysis. It has been shown that cocrystals of betulin with suberic acid contain water molecules in their structure; anhydrous cocrystals can be obtained by heating a physical mixture of reagents until the acid melts. The results of experiments on the dissolution of cocrystals of betulin with suberic acid in comparison with the data for cocrystals of betulin with adipic acid showed that an increase in the length of the aliphatic acid chain leads to a decrease in the rate of betulin release into solution.

Secondary Metabolites with Cytotoxic Activities from Streptomyces sp. BM-8 Isolated from the Feces of Equusquagga

A new aliphatic acid, compound 1, together with six known metabolites, including nonactic acid (2), homononactic acid (3), ethyl homononactate (4), homononactylhomononactate (5), valinomycin (6), and cyclo-(Pro-Leu) (7), was isolated from the culture broth of Streptomyces sp. BM-8, an actinobacterial strain isolated from the feces of Equus quagga. The structures of these compounds were established by analyses of spectroscopic data, including 1D and 2D nuclear magnetic resonance spectra (NMR), as well as by HR-ESI-MS spectrometry and chemical derivative analyses. Additionally, a serial analogue of nonactic acid and homononacticacid (8–21) was synthesized. The cytotoxicity of 1–21 wastested against a panel of cancer cell lines, such as HT-29, MCF-7, A375 and K562, with MTT assay. In addition, the cytotoxicity tests revealed that 1 was less cytotoxic toward a panel of cancerous cells, as compared with valinomycin (6).

The importance of Cu × Pb interactions to Lentinula edodes yield, major/trace elements accumulation and antioxidants

Due to the use of various substrates in the production of edible mushrooms which may contain metals, including Cu and Pb, it is important to understand the influence of mutual interactions between them in the process of their accumulation in fruit bodies. For this reason, the effects of Cu, Pb, and Cu × Pb on yield, accumulation of five major elements (Ca, K, Mg, Na and P), trace elements (Cu, Pb and Fe) and some bioactive compounds in Lentinula edodes fruit bodies were studied. Both the metals were added in doses of 0.1 and 0.5 mM (Cu0.1, Cu0.5, Pb0.1, Pb0.5 and their combinations). The addition of the metals resulted in a reduction in size, amount and finally yield of fruit bodies. Depending on the presence of Cu and or Pb and their concentration in the substrate, both antagonism and synergism may occur. The influence on the accumulation of other determining elements was also recorded. Among phenolic compounds, phenolic acids and flavonoids were detected. 2,5-Dihydroxybenzoic acid dominated in fruit bodies in the control variant, Pb0.1, Pb0.5 and all experimental variants enriched with Cu + Pb, while gallic acid was the major phenolic after Cu0.1 and Cu0.5 addition. Only protocatechuic acid content increased in all combinations. A significant decrease of all aliphatic acid contents in comparison to the control variant was observed in the Cu0.1 and Pb0.1 variants. Significant stimulation of aliphatic acid synthesis was recorded in Cu0.5 and Pb0.5 variants and in the mixture of both the metals. The additions pointed to the possible role of the determined molecules in detoxification mechanisms.

Honey: Determination of volatile compounds, antioxidant and antibacterial activities

Honey is an important functional food for human health and nutrition that is collected by honey bees and stored in the honeycombs. In this study, total phenolic content, antioxidant activity and volatile compounds of 13 different honey samples collected from various districts of Malatya province were investigated. As a result of this study, it was determined that the total phenolic content varied between 8.50 mg GAE 100 g^–1 and 73.90 mg GAE 100 g^–1and it was observed that the honey samples were rich in aldehydes, aliphatic acid and esters, alcohols, hydrocarbons, carboxylic acid esters, ketones, terpenes, fatty acids and esters. In addition, the antibacterial effects of honey samples were determined against 18 different pathogenic bacteria using agar well diffusion (AWD) method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). In AWD assay, it was recorded that inhibition zone diameters varied between 9 mm and 14 mm and honey samples were found to have a partial inhibitory effect against selected target pathogens.

Lipase-catalyzed selective esterification of catechin

Catechins show strong antioxidant, antitumoral, antiviral, and anti-inflammatory activities. The uses of catechins in food, cosmetic, and pharmaceutical formulations seem very attractive. Unfortunately, solubility and stability of catechins are poor in apolar media, which limits their efficient uses. In order to improve the solubility of catechins in the oil phase and maintain their oxidation resistance, a regioselective enzymatic acylation was investigated. The effects of reaction medium, water content, carbon chain length of acyl donor and other factors on the acylation reaction were studied, catechins were enzymatically esterified with an aliphatic acid (stearic acid) using an immobilized lipase Novozym 435 in n-butanol. The results show that when the ratio between catechins and stearic acid was 1:5, adding molecular sieves 4A after 11 h of reaction and the temperature of 60 °C led to the maximum conversion yield of 60.36%. Studies have shown that catechin stearate has a higher antioxidant activity than vitamin E and dibutyl hydroxytoluene (BHT).

Novel Series of 1,3,4- Oxadiazole Derivatives: Evaluation of Thermal Properties and Antibacterial Activity

A new series of 1,3,4-oxadiazole derivatives were synthesized 6(a-i) by the reaction between respective aliphatic acid hydrazides with p-alkoxy aldehydes using chloramine-T (CAT). The synthesized compounds were evaluated for their thermal properties using Polarising Optical Microscopy (POM), Differential Scanning Calorimetry (DSC), and variable temperature Powder X-RD (PXRD). The compounds exhibited spherulitic textures associated with the crystal to isotropic phase. No mesophase was detected upon heating or cooling cycles. Also, the synthesized compounds showed moderate to good antibacterial activity.