The polyphenolic profiles and antioxidant effects of Agastache rugosa Kuntze (Banga) flower,leaf, stem and root

Agastache rugosa Kuntze (Korean mint) is used as a spice and in folk medicine in East Asia. The present study identified a total of 18 polyphenols from the flower, leaf, stem and roots of this plant using high‐performance liquid chromatography–tandem mass spectrometry. Fourteen of these compounds had not previously been identified in these plant tissues. Each polyphenol was validated in comparison with external calibration curves constructed using structurally related compounds, with determination coefficients >0.9993. The limits of detection and quantification were 0.092–0.650 and 0.307–2.167 mg/L, respectively. Recoveries of 61.92–116.44% were observed at two spiking levels, with 0.91–11% precision, expressed as relative standard deviation (except anthraquinone spiked at 10 mg/L). Hydroxycinnamic acid was the most abundant compound in the root, while the flowers showed the highest total flavonoid level. Antioxidant activities, determined in terms of reducing power, Fe²⁺ chelating activity and the radical scavenging activities using α,α‐diphenyl‐β‐picrylhydrazyl and 2‐2?‐azino‐bis‐3‐ethylbenzothiazoline‐6‐sulfonic acid, increased in a concentration‐dependent manner; the highest activity was identified in the stems, followed by leaves > flowers > roots. These findings indicate that A. rugosa is a good source of bioactive compounds and can be used as a functional food. Copyright © 2015 John Wiley & Sons, Ltd.     

Cyclodimers and Cyclotrimers of 2,3 -Bisalkynylated Anthracenes,Phenazines and Diazatetracenes

The synthesis of novel (N−)acene-based cyclooligomers is reported. Glaser-Hay coupling of the bisethynylated monomers results in cyclodimers and cyclotrimers that are separable by column and gel-permeation chromatographies. For the diazatetracene, the use of sec-butyl-silylethynyl groups is necessary to achieve solubility. Diazatetracene-based cyclodimers and cyclotrimers were used as semiconductors in thin-film transistors. Although their optoelectronic properties are quite similar, their electron mobilities in proof-of-concept thin-film transistors differ by an order of magnitude.     

Exploiting Aggregation To Achieve Phase Separation in Macrocyclization

The aggregation properties of poly(ethylene glycol) (PEG) can be exploited in organic synthesis to control dilution effects. Through the use of solvent mixtures containing PEG₄₀₀/MeOH, macrocyclization by Glaser–Hay coupling can be conducted at high concentrations. The origin of the selectivity has been studied by using surface tension measurements, UV spectroscopy, and chemical tagging and demonstrates the dependence of the yield and selectivity on the aggregation of PEG₄₀₀ and its ability to preferentially solubilize organic substrates, resulting in a phase separation from the catalyst system.     

1,3-Diyne chemistry: synthesis and derivations

Conjugated diynes have attracted more and more attention not only for their unique rod like structures and wide existence in nature product, but also the abundant properties and derivations of them. Although oxidative dimerization of alkynes or Cadiot–Chodkiewicz reactions were the main pathway and have achieved great success in the synthesis of diynes, oxidative cross coupling, FBW rearrangement as well as diyne metathesis emerged rapidly recently. Moreover, diynes could be precursors of basic heterocycles, which represented an emerging research area. This Letter will cover the recent progresses in the synthesis and further derivations of diynes.     

Chemical Analyses and Antimicrobial Activity of Nine Kinds of Unifloral Chinese Honeys Compared to Manuka Honey (12+ and 20+)

Honey has good antimicrobial properties and can be used for medical treatment. The antimicrobial properties of unifloral honey varieties are different. In this study, we evaluated the antimicrobial and antioxidant activities of nine kinds of Chinese monofloral honeys. In addition, headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) technology was used to detect their volatile components. The relevant results are as follows: 1. The agar diffusion test showed that the diameter of inhibition zone against Staphylococcus aureus of Fennel honey (21.50 ± 0.41 mm), Agastache honey (20.74 ± 0.37 mm), and Pomegranate honey (18.16 ± 0.11 mm) was larger than that of Manuka 12+ honey (14.27 ± 0.10 mm) and Manuka 20+ honey (16.52 ± 0.12 mm). The antimicrobial activity of Chinese honey depends on hydrogen peroxide. 2. The total antioxidant capacity of Fennel honey, Agastache honey, and Pomegranate honey was higher than that of other Chinese honeys. There was a significant positive correlation between the total antioxidant capacity and the total phenol content of Chinese honey (r = 0.958). The correlation coefficient between the chroma value of Chinese honey and the total antioxidant and the diameter of inhibition zone was 0.940 and 0.746, respectively. The analyzed dark honeys had better antimicrobial and antioxidant activities. 3. There were significant differences in volatile components among Fennel honey, Agastache honey, Pomegranate honey, and Manuka honey. Hexanal-D and Heptanol were the characteristic components of Fennel honey and Pomegranate honey, respectively. Ethyl 2-methylbutyrate and 3-methylpentanoic acids were the unique compounds of Agastache honey. The flavor fingerprints of the honey samples from different plants can be successfully built using HS-GC-IMS and principal component analysis (PCA) based on their volatile compounds. Fennel honey, Agastache honey, and Pomegranate honey are Chinese honey varieties with excellent antimicrobial properties, and have the potential to be developed into medical grade honey.     

Development and Optimization of Djulis Sourdough Bread Fermented by Lactic Acid Bacteria for Antioxidant Capacity

This study developed a nutritionally valuable product with bioactive activity that improves the quality of bread. Djulis (Chenopodium formosanum), a native plant of Taiwan, was fermented using 23 different lactic acid bacteria strains. Lactobacillus casei BCRC10697 was identified as the ideal strain for fermentation, as it lowered the pH value of samples to 4.6 and demonstrated proteolysis ability 1.88 times higher than controls after 24 h of fermentation. Response surface methodology was adopted to optimize the djulis fermentation conditions for trolox equivalent antioxidant capacity (TEAC). The optimal conditions were a temperature of 33.5 °C, fructose content of 7.7%, and dough yield of 332.8, which yielded a TEAC at 6.82 mmol/kg. A 63% increase in TEAC and 20% increase in DPPH were observed when compared with unfermented djulis. Subsequently, the fermented djulis was used in different proportions as a substitute for wheat flour to make bread. The total phenolic and flavonoid compounds were 4.23 mg GAE/g and 3.46 mg QE/g, marking respective increases of 18% and 40% when the djulis was added. Texture analysis revealed that adding djulis increased the hardness and chewiness of sourdough breads. It also extended their shelf life by approximately 2 days. Thus, adding djulis to sourdough can enhance the functionality of breads and may provide a potential basis for developing djulis-based functional food.     

Specific features of the chemical behavior of acetylenic derivatives of benzocrown ethers

4"-Ethynylbenzo-12-crown-4 (8), 4"-ethynylbenzo-15-crown-5 (9), and 4"-ethynylbenzo-18-crown-6 (10) were synthesized by cross-coupling of the corresponding aryl iodides 1—3 with 2-methylbut-3-yn-2-ol (4a) followed by the retro-Favorsky cleavage of the resulting carbinols. Unlike the corresponding benzo-12-crown-4 derivative (5a), the cleavage of tertiary acetylenic alcohols of benzo-15-crown-5 (6a) and benzo-18-crown-6 (7a) requires more than one molar equivalent of KOH. Aminoalkylation of crown ether 8 gives Mannich bases, independently of the reaction conditions and the nature of amine. The aminomethylation of acetylenic crown ethers 9 and 10 with paraform—piperidine (morpholine) in the presence of CuCl yields 1,4-disubstituted buta-1,3-diynes (19, 20) rather than Mannich bases.     

Certified reference materials—Hay Powder (CRM 129) and Rye Grass (CRM 281)—for the quality control of analysis of animal feed

Analyses of nutritive elements are routinely performed in grass or hay for animal feed in order to improve the state of health and growth of domestic animals. To control the quality of such determinations, the Community Bureau of Reference (BCR) so far has produced two certified reference materials: Hay Powder (CRM 129) and Rye Grass (CRM 281). After a careful preparation procedure of the materials, a homogeneity study and a long-term stability study, the contents of the elements Ca, K, Mg, P, S, Zn, I, N and Kjeldahl-N were certified in CRM 129, whereas CRM 281 was certified for As, B, Cd, Cu, Hg, Mn, Mo, Ni, Pb, Sb, Se and Zn. This paper presents the certification exercise and especially concentrates on the elements I, B and Mo as examples of analytical work. Indicative values for Co, Cr, Fe, Cl and Na were also obtained.     

Protective Effect of Djulis (Chenopodium formosanum) Extract against UV- and AGEs-Induced Skin Aging via Alleviating Oxidative Stress and Collagen Degradation

Skin aging is a complex process involving photoaging and glycation stress, which share some fundamental pathways and have common mediators. They can cause skin damage and collagen degradation by inducing oxidative stress and the accumulation of reactive oxygen species (ROS). Chenopodium formosanum (CF), also known as Djulis, is a traditional cereal in Taiwan. This study investigated the protection mechanisms of CF extract against ultraviolet (UV) radiation and advanced glycation end products (AGEs)-induced stress. The results indicated that CF extract had strong antioxidant and free radical scavenging effects. It could reduce UV-induced intracellular ROS generation and initiate the antioxidant defense system by activating the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway in human skin fibroblasts. CF extract modulated mitogen-activated protein kinase (MAPK) and transformed growth factor-beta (TGF-β) signaling pathways to alleviate oxidative stress-induced skin aging. Moreover, the results revealed that CF extract not only promoted collagen synthesis but also improved aging-induced collagen degradation. CF extract attenuated AGEs-induced ROS production and the upregulation of receptor for AGEs (RAGE). The overall results suggest that CF extract provides an effective anti-aging strategy by preventing skin damage from oxidative stress and collagen loss with potent antioxidant, anti-photoaging, and antiglycation activities.     

Improving livestock feed safety and infection prevention: Removal of bacterial contaminants from hay using cold water,bubbles and ultrasound

The ingestion of contaminated hay is detrimental to livestock wellbeing. In this study, the feasibility of using an ultrasonically activated stream (UAS) to clean bacterial contamination from hay was investigated. Hay samples were stained with SYTO-9 nucleic acid stain for the in-situ visualization of microbes on the surface using an episcopic differential interference contrast microscope coupled with epi-fluorescence. The total microbial load per sample was calculated by measuring the mean percentage area of SYTO-9 positive staining. The cleaning efficacy was evaluated by comparing the total microbial coverage before and after cleaning. The cleaning performance between an UAS and a non UAS were compared and results have shown that an exposure of 60 s to an UAS demonstrated an 87.94 ± 2.22% removal of the bacterial contaminants, exceeding that of non UAS (21.85 ± 13.63% removal). UAS is capable of removing bacterial contaminants without the use of antimicrobial agents, therefore its cleaning mechanism can potentially prevent infection and reduce antimicrobial resistance. The cleaning mechanism of UAS can be adapted for the development of a new hay cleaning strategy for effective removal of bacterial contaminant to improve feed safety.