Structure and Cytotoxicity of Novel Lignans and Lignan Glycosides from the Aerial Parts of Larrea tridentata

Previously, the authors conducted phytochemical investigations of the aerial parts of Larrea tridentata and reported triterpene glycosides and lignan derivatives. In continuation of the preceding studies, 17 lignans and lignan glycosides (1–17) were isolated, including seven new compounds (1–7). Herein, the structure of the new compounds was determined based on spectroscopic analysis and enzymatic hydrolysis. The cytotoxicity of 1–17 against HL-60 human promyelocytic leukemia cells was examined. Compounds 4–11 and 14–16 were cytotoxic to HL-60 cells, with IC₅₀ values in the range of 2.7–17 μM. Compound 6, which was the most cytotoxic among the unprecedented compounds, was shown to induce apoptotic cell death in HL-60 cells.     

Analogs of pyrimidine nucleosides. 19. Synthesis,antineoplastic activity,and kinetics of the hydrolysis of 1-(3-phthalidyl)-5-fluorouracils

1-(3-Phthalidyl)-5-fluorouracils were synthesized by alkylation of 2,4-bis(trimethylsilyl)-5-fluorouracil with substituted 3-bromophthalides, and the rate constants for hydrolysis at pH 8.0–11.5 were determined. The antineoplastic activity of a number of the compounds was established, and it was assumed that there is a relationship between the biological activity and the rate of hydrolysis.See [1] for communication 18.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1406–1411, October, 1985.     

Hydrolysis of 1,2-disubstituted imidazolines in aqueous media

The kinetics of hydrolysis of 1,2-disubstituted imidazolines in aqueous media was studied (pH 2.0—12.5, T = 25—90 °C) by UV spectroscopy. The hydrolysis products were identified. The introduction of a branched substituent into position 2 of the imidazoline ring increases the hydrolytic stability of the compounds. The effect of the pH on the hydrolysis rate of imidazolines is discussed.     

Bodiniosides S–Y,Seven New Triterpenoid Saponins from Elsholtzia bodinieri and Their Anti-Influenza Activities

Investigation of the n-BuOH extract of the aerial parts of Elsholtzia bodinieri led to the isolation of seven new triterpenoid saponins, Bodiniosides S–Y (1–7, resp.). Their strictures were elucidated on the basis of spectroscopic techniques, including HSQC, HSBC, and HSQC–TOCSY experiments, together with acid hydrolysis and GC analysis. The anti-influenza activities of compounds 1–7 were evaluated against A/WSN/33/2009 (H1N1) virus in MDCK cells. The results showed that compounds 2 and 5 exhibited moderate anti-influenza activities against A/WSN/33/2009 (H1N1), with inhibition rates of 35.33% and 24.08%, respectively.     

Phosphorus-containing Aminocarboxylic Acids: XIV. Synthesis of Analogs of α-Substituted Glutamic Acid

Addition of Schiff bases derived from amino acid esters to appropriate vinylphosphoryl compounds, followed by hydrolysis of the adducts formed gives a series of new α-alkylated phosphorus-containing α-aminocarboxylic acids, viz. phosphonic and phosphinic analogs of glutamic acid.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 7, 2005, pp. 1140–1147.Original Russian Text Copyright © 2005 by Saratovskikh, Ragulin.     

Kinetics of hydrolysis of some new heterocyclic azomethines

Kinetics of base hydrolysis of new heterocyclic azomethines derived from active methyl quaternary salts and aromatic nitroso compounds were investigated in the presence of 70% (wt/wt) water-methanol. The base hydrolysis of these compounds is strictly first-order with respect to OH^– and azomethine. The rate determining step is suggested to be the attack of the hydroxide ion on the free base. Effects of water content and nature of organic hydroxylic solvent have been studied. It is concluded that specific solute-solvent interactions through dispersion forces play a major role in the base hydrolysis rate of the azomethines investigated. The effect of pH (2.98 – 12.24) on hydrolysis rates of compounds having a diethylamino substituent in the presence of 30% methanol has been studied. In acidic media, the rate determining step is probably the water attack on the protonated substrate.     

Reactions of cyclammonium cations

Heterocyclic derivatives of thiazolidones were obtained by the reaction of six-membered nitrogen heterocycles with thiazolidones in the presence of acyl halides. The compounds obtained were converted to heterocyclic thioglycolic acids by alkaline hydrolysis.See [1] for communication XX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1359–1365, October, 1972.     

Investigations in the field of imidazo[1,2-a]benzimidazole

The nitrosation and azo coupling reactions in the imidazo[1,2-a]benzimidazole series have been studied. Position 3 of the system undergoes attack. The nitroso compounds readily undergo hydrolysis in acid and alkaline media at the 1–2 bond with the formation of derivatives of benzimidazolone or 2-iminobenzimidazoline.For Communication II, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii.Vol. 6, No. 7, pp. 977–980, July, 1970.     

Brasesquilignan A–E,Five New Furofurans Lignans from Selaginella braunii Baker

Five new furofurans lignans, Brasesquilignan A–E (1–5), were isolated from the aqueous ethanol extract of Selaginella braunii Baker. Their structures were elucidated by extensive analysis of NMR and HRESIMS data. Their absolute configurations were determined by CD spectra, enzymatic hydrolysis, and GCMS analysis. Furthermore, all compounds were evaluated for anti-proliferative activities against various human cancer cellsin vitro. Compounds 2 and 3 exhibited weak inhibitorypotency against five human cancer cells.     

Mesoionic 2-acylimino-1,3,4-thia- and -oxadiazoles

2-Acylimino-1,3,4-thiadiazoles were obtained from 1-methyl-1-thioacylhydrazines and the appropriate acyl isothiocyanates, while 2-benzoylimino-1,3,4-oxadiazole was obtained from 1-phenyl-1-benzoylhydrazine and benzoyliminocarbonic acid dichloride. The mesoionic structure of the compounds obtained was proved by their IR and mass spectra. Reduction, hydrolysis, and salt-formation reactions of them were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1345–1350, October, 1973.     

Mass spectrometric study of products and intermediate compounds in oscillating chemical reactions of oxidation of macrocyclic copper and nickel complexes by a bromate

Products and intermediate compounds formed in oscillating chemical reactions of oxidation of copper and nickel tetraazamacrocyclic complexes were studied by the method of desorption field mass spectrometry. It was shown that a cascadelike oxidation of the macrocyclic ligand takes place and its hydrolysis with rupture of the macrocyclic ring at the azomethine bonds. Products of bromination of oxygen- and nitrogen-containing compounds, participants in the reactions, were discovered.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 23, No. 2, pp. 221–225, March–April, 1987.     

4-Azaindane-1,3-dione derivatives. III. Reactivities and prototropic transformations of new 4-azaindane-1,3-diones

New 4-azaindane-1,3-dione derivatives were synthesized from 3-ethoxalyl-5-R-cyclopentane-1,2,4-trione and aliphatic -aminovinylcarbonyl compounds. The halogenation, reduction, and hydrolysis of the synthesized compounds were investigated. The prototropic equilibria of 4-azaindane-1,3-diones were studied.See [1] for communication II.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 256–262, February, 1976.     

RNA-inspired intramolecular transesterification accelerates the hydrolysis of polyethylene-like polyphosphoesters

To synthesize new (bio)degradable alternatives to commodity polymers, adapting natural motives can be a promising approach. We present the synthesis and characterization of degradable polyethylene (PE)-like polyphosphoesters, which exhibit increased degradation rates due to an intra-molecular transesterification similar to RNA. An α,ω-diene monomer was synthesized in three steps starting from readily available compounds. By acyclic diene metathesis (ADMET) polymerization, PE-like polymers with molecular weights up to 38 400 g mol⁻¹ were obtained. Post-polymerization functionalization gave fully saturated and semicrystalline polymers with a precise spacing of 20 CH₂ groups between each phosphate group carrying an ethoxy hydroxyl side chain. This side chain was capable of intramolecular transesterification with the main-chain similar to RNA-hydrolysis, mimicking the 2′-OH group of ribose. Thermal properties were characterized by differential scanning calorimetry (DSC (T_mca. 85 °C)) and the crystal structure was investigated by wide-angle X-ray scattering (WAXS). Polymer films immersed in aqueous solutions at different pH values proved an accelerated degradation compared to structurally similar polyphosphoesters without pendant ethoxy hydroxyl groups. Polymer degradation proceeded also in artificial seawater (pH = 8), while the polymer was stable at physiological pH of 7.4. The degradation mechanism followed the intra-molecular “RNA-inspired” transesterification which was detected by NMR spectroscopy as well as by monitoring the hydrolysis of a polymer blend of a polyphosphoester without pendant OH-group and the RNA-inspired polymer, proving selective hydrolysis of the latter. This mechanism has been further supported by the DFT calculations. The “RNA-inspired” degradation of polymers could play an important part in accelerating the hydrolysis of polymers and plastics in natural environments, e.g. seawater.

RNA-inspired degradation of polyethylene-like polyphosphoesters accelerates the backbone hydrolysis dramatically to guarantee seawater-degradable plastics.     

Determination of Activation Energies and the Optimum Temperatures of Hydrolysis of Starch by α-Amylase from Porcine Pancreas

The present paper reports the determination of the activation energies and the optimum temperatures of starch hydrolysis by porcine pancreas α-amylase. The parameters were estimated based on the literature data on the activity curves versus temperature for starch hydrolysis by α-amylase from porcine pancreas. It was assumed that both the hydrolysis reaction process and the deactivation process of α-amylase were first-order reactions by the enzyme concentration. A mathematical model describing the effect of temperature on porcine pancreas α-amylase activity was used. The determine deactivation energies E_a were from 19.82 ± 7.22 kJ/mol to 128.80 ± 9.27 kJ/mol, the obtained optimum temperatures T_opt were in the range from 311.06 ± 1.10 K to 326.52 ± 1.75 K. In turn, the values of deactivation energies E_d has been noted in the range from 123.57 ± 14.17 kJ/mol to 209.37 ± 5.17 kJ/mol. The present study is related to the starch hydrolysis by α-amylase. In the industry, the obtained results the values E_a, E_d, T_opt can be used to design and optimize starch hydrolysis by α-amylase porcine pancreas. The obtained results might also find application in research on the pharmaceutical preparations used to treat pancreatic insufficiency or prognosis of pancreatic cancer.     

Content of Phenolic Compounds in Meadow Vegetation and Soil Depending on the Isolation Method

The aim of this paper was to determine the effect of the hydrolysis method on the amounts of phenolic compounds in the plant material in soil and, as a consequence, on the parameters to determine the degree of lignins transformation in soils. The study included the plant material (hay, sward, and roots) and soil—Albic Brunic Arenosol (horizon A, AE, and Bsv) samples. Phenolic compounds were isolated at two stages by applying acid hydrolysis followed by alkaline re-hydrolysis. The quantitative and qualitative analysis of phenolic compounds was performed with high-performance liquid chromatography with a DAD. The content of phenolic compounds in the extracts depended on the hydrolysis method and it was determined by the type of the research material. The amounts of phenolic compounds contained in the alkaline hydrolysates accounted for 55.7% (soil, horizon Bsv)—454% (roots) of their content in acid hydrolysates. In the extracts from acid hydrolysates, chlorogenic and p-hydroxybenzoic acids were dominant. In the alkaline extracts from the plant material, the highest content was recorded for p-coumaric and ferulic acids, and in the extracts from soil, ferulic and chlorogenic acids. A combination of acid and alkaline hydrolysis ensures the best extraction efficiency of insoluble-bound forms of polyphenols from plant and soil material.     

Hydrolyzed Flavonoids from Cyrtosperma johnstonii with Superior Antioxidant,Antiproliferative, and Anti-Inflammatory Potential for Cancer Prevention

Cyrtosperma johnstonii is one of the most interesting traditional medicines for cancer treatment. This study aimed to compare and combine the biological activities related to cancer prevention of the flavonoid glycosides rutin (RT) and isorhamnetin-3-o-rutinoside (IRR) and their hydrolysis products quercetin (QT) and isorhamnetin (IR) from C. johnstonii extract. ABTS and MTT assays were used to determine antioxidant activity and cytotoxicity against various cancer cells, as well as normal cells. Anti-inflammatory activities were measured by ELISA. The results showed that the antioxidant activities of the compounds decreased in the order of QT > IR > RT > IRR, while most leukemia cell lines were sensitive to QT and IR with low toxicity towards PBMCs. The reduction of IL-6 and IL-10 secretion by QT and IR was higher than that induced by RT and IRR. The combination of hydrolysis products (QT and IR) possessed a strong synergism in antioxidant, antiproliferative and anti-inflammatory effects, whereas the combination of flavonoid glycosides and their hydrolysis products revealed antagonism. These results suggest that the potential of the combination of hydrolyzed flavonoids from C. johnstonii can be considered as natural compounds for the prevention of cancer.     

Hydrolysis of the reaction products of hexaethyltriamidophosphite and 2-diethylaminomethyl-6-methylphenol

Conclusions The authors study the hydrolysis of some pentavalent compounds of phosphorus containing phosphaindan heterocyclic groups and a P-N bond. Hydrolysis leads to rupture or retention of the phosphaindan heterocyclic group, depending on the structure.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 154–156, January, 1969.     

Indolizines. 6. Relative reactivities of isomeric 6-, 7-, and 8-ethoxycarbonylindolizine derivatives

The kinetics of the alkaline hydrolysis of 2-phenyl-6-, -7-, and -8-ethoxycarbonylindolizines were studied. The rate constants for the hydrolysis of these compounds and the indexes of the dissociation constants of 2-phenylindolizine-6-,-7-, and -8-carboxylic acids were determined by spectrophotometry. The indexes of the electronic structures and reactivities of 2-methyl-6-, -7-, and -8-ethoxycarbonylindolizines were calculated from theory.See [1] for Communication [5].Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 627–633, May, 1979.     

Personal Glucose Meter for α-Glucosidase Inhibitor Screening Based on the Hydrolysis of Maltose

As a key enzyme regulating postprandial blood glucose, α-Glucosidase is considered to be an effective target for the treatment of diabetes mellitus. In this study, a simple, rapid, and effective method for enzyme inhibitors screening assay was established based on α-glucosidase catalyzes reactions in a personal glucose meter (PGM). α-glucosidase catalyzes the hydrolysis of maltose to produce glucose, which triggers the reduction of ferricyanide (K₃[Fe(CN)₆]) to ferrocyanide (K₄[Fe(CN)₆]) and generates the PGM detectable signals. When the α-glucosidase inhibitor (such as acarbose) is added, the yield of glucose and the readout of PGM decreased accordingly. This method can achieve the direct determination of α-glucosidase activity by the PGM as simple as the blood glucose tests. Under the optimal experimental conditions, the developed method was applied to evaluate the inhibitory activity of thirty-four small-molecule compounds and eighteen medicinal plants extracts on α-glucosidase. The results exhibit that lithospermic acid (52.5 ± 3.0%) and protocatechualdehyde (36.8 ± 2.8%) have higher inhibitory activity than that of positive control acarbose (31.5 ± 2.5%) at the same final concentration of 5.0 mM. Besides, the lemon extract has a good inhibitory effect on α-glucosidase with a percentage of inhibition of 43.3 ± 3.5%. Finally, the binding sites and modes of four active small-molecule compounds to α-glucosidase were investigated by molecular docking analysis. These results indicate that the PGM method is feasible to screening inhibitors from natural products with simple and rapid operations.     

Hydrolysis of hydro(pyrrolyl-1)borates

The hydrolysis of hydro(pyrrolyl-l)borates ([BH_n(NC₄H₄)_4-n]⁻, n = 1,2,3) can be treated as a kinetically one-step reaction outside of the mildly acidic region. In strongly acidic medium the hydrolysis takes place in a stepwise manner; the intermediates (boranes and the cationic boron compounds) being hydrolyzed more slowly than the borate anion. In the first step of the hydrolysis of [BH₃(NC₄H₄)]⁻ the B---H bond, while in case of [BH₂(NC₄H₄)₂]⁻ and [BH(NC₄H₄)₃]⁻ the B---N bond is breaking.In neutral and mildly alkaline medium, the hydrolysis is a general acid catalyzed reaction (A---S_E2 mechanism). It becomes to a special H⁺-ion catalyzed reaction (A-1 mechanism) in strongly alkaline region since the protonated intermediate can be reversed to the original borate upon reaction with the OH⁻ ion. The hydrolysis presumably takes place through an intermediate which is protonated on the pyrrolyl nitrogen. Concomitant to the hydrolysis an isotopic exchange reaction was observed on the C_α and C_β atoms of the pyrrolyl group in heavy water. In the hydrolysis of the [BH₃(NC₄H₄)]⁻-anion the N-protonated intermediate is assumed to be able to reverse to the original borate even in acidic or neutral region, at least in part.