Synthesis of Three Asymmetric N-Confused Tetraarylporphyrins

Two monosubstituted and one tetrasubstituted N-confused porphyrins (1–3) were prepared in ca. 3–5% yields using a [2 + 2] synthesis. The monosubstituted porphyrins have carbomethoxy (1) or nitro (2) substituents on one of the meso-phenyl groups, while the meso-phenyl groups of the third NCP (3) are substituted with nitro, bromo, and methyl groups in an AB2C pattern. The specific regiochemistry of the aryl rings around the macrocycle in each porphyrin was definitively determined using a combination of 1D (1H and 13C) and 2D (gHMBC, gHSQC and ROESY) NMR spectroscopy. The absorption spectra of 1–3 in CH2Cl2 are similar to those of N-confused tetraphenylporphyrin (NCTPP) but have Soret and Q bands that are shifted to lower energies with smaller extinction coefficients in comparison to those for NCTPP

Sugar-Functional Vinyl Addition Poly(norbornene)–Photopatternable Poly(norbornenyl gluconamide) Compositions Developed with Water

The norbornenyl gluconamide (NBGA) monomer can be polymerized by a number of palladium catalysts to give water-soluble, vinyl addition poly­(NBGA). Depending on the catalyst used, the reaction conditions, and the chain-transfer additives employed, high-molecular-weight polymers can be obtained. These polymers can be thermally cross-linked at ca. 190 °C or at ca. 150 °C when the difunctional glutaraldehyde is added. A photopatternable composition is formed by the addition of a water-soluble diazide when the poly­(NBGA) molecular weight is sufficiently high. After image-wise exposure, negative-tone patterns are revealed by water development. A detailed analysis of NBGA monomer structures by high-resolution nuclear magnetic resonance techniques including pure shift is reported showing that two diastereomers of each endo- and exo-isomer are formed from the reaction of norbornene methylamine and δ-gluconolactone

Modeling Relationships among Active Components in Black Raspberry (Rubus occidentalis L.) Fruit Extracts Using High-Resolution ¹H Nuclear Magnetic Resonance (NMR) Spectroscopy and Multivariate Statistical Analysis

A process was developed to ascertain the bioactive components of black raspberry (Rubus occidentalis L.) fruit extracts by relating chemical constituents determined by high-field nuclear magnetic resonance (NMR) spectroscopy to biological responses using partial least-squares regression analysis. To validate our approach, we outlined relationships between phenolic signals in NMR spectra and chemical data for total monomeric anthocyanin (TMA) content and antioxidant capacity by the ferric-reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. Anthocyanins, cyanidin 3-O-rutinoside (Cy 3-rut), cyanidin 3-O-(2(G))-xylosylrutinoside (Cy 3-xylrut), and cyanidin 3-O-glucoside (Cy 3-glc), were significant contributors to the variability in assay results, with the two most important NMR bins corresponding to the methyl peaks in Cy 3-rut (6′′′) and/or Cy 3-xylrut (6IV). Many statistically important bins were common among assay models, but differences in structure−activity relationships resulted in changes in bin ranking. The specificity of these results supported the application of the process to investigate relationships among health-beneficial natural products and potential biological activity

Nonanthocyanin Secondary Metabolites of Black Raspberry (<i>Rubus occidentalis</i> L.) Fruits: Identification by HPLC-DAD, NMR, HPLC-ESI-MS, and ESI-MS/MS Analyses

Nonanthocyanin secondary metabolites potentially contributing to the antiproliferative bioactivity of black raspberry (Rubus occidentalis L.) fruits were extracted in ethyl acetate and isolated by semipreparative and analytical HPLC and analyzed by NMR, HPLC-ESI-MS, and ESI-MS/MS techniques. Here we present complete and partial structures of a variety of the chemical entities such as quercetin 3-glucoside, quercetin 3-rutinoside, myricetin glucoside, dihydrokaempferol glucoside, benzoic acid β-d-glucopyranosyl ester, 3,4-dihydroxybenzoic acid, epicatechin, caffeic acid, <i>p-</i>coumaric acid, <i>p-</i>coumaryl glucoside, <i>p-</i>coumaryl sugar ester, ellagic acid, methyl ellagic acid acetylpentose, methyl ellagic acid valerylpentose, <i>trans</i>-piceid, phloretin glucoside (phloridzin), dihydrosinapic acid, salicylic acid β-d-glucopyranosyl ester, a salicylic acid derivative without attached sugar, <i>p-</i>alkylphenyl glucoside, and a citric acid derivative. To our knowledge, 15 of these compounds were not previously reported in black raspberry fruits

NMR-Based Metabolomic Investigation of Bioactivity of Chemical Constituents in Black Raspberry (Rubus occidentalis L.) Fruit Extracts

Black raspberry (Rubus occidentalis L.) (BR) fruit extracts with differing compound profiles have shown variable antiproliferative activities against HT-29 colon cancer cell lines. This study used partial least-squares (PLS) regression analysis to develop a high-resolution ¹H NMR-based multivariate statistical model for discerning the biological activity of BR constituents. This model identified specific bioactive compounds and ascertained their relative contribution against cancer cell proliferation. Cyanidin 3-rutinoside and cyanidin 3-xylosylrutinoside were the predominant contributors to the extract bioactivity, but salicylic acid derivatives (e.g., salicylic acid glucosyl ester), quercetin 3-glucoside, quercetin 3-rutinoside, <i>p</i>-coumaric acid, epicatechin, methyl ellagic acid derivatives (e.g., methyl ellagic acetyl pentose), and citric acid derivatives also contributed significantly to the antiproliferative activity of the berry extracts. This approach enabled the identification of new bioactive components in BR fruits and demonstrates the utility of the method for assessing chemopreventive compounds in foods and food products