Specific antitumor activity and mechanism of protonic bis-phenanthroline / 药学学报

Hepatocellular carcinoma (HCC) is a common malignant tumor worldwise. The incidence rate of HCC is high and is easy to metastasis and recurrence, which seriously affects human health. Traditional chemical drugs have some challenges such as toxicity, side effects, and multidrug resistance, thus it is urgent to find new drugs and effective targets. Here we synthesized a novel chemical, protonic bis-phenanthroline (H-BP), and the antitumor effect was investigated in the study. The results showed that H-BP could selectively inhibit the proliferation of tumor cells and cause HCC apoptosis. And also, in HCC tumor-bearing mice, H-BP could effectively prevent the growth of tumor mass, even completely eliminate the tumor at medium dose (5 mg·kg-1) and high dose (10 mg·kg-1), and meanwhile H-BP has no significant effect on the body weight of mice. The experimental protocol was approved by the Animal Ethics Committee of Southwest University, and the experimental operation was strictly carried out in accordance with the ethical principles of animal use and care. Mechanism studies showed that H-BP induced HCC apoptosis was related to down-regulation the expression of pleomorphic adenoma gene like-2 (PLAGL2), a oncogene transcription factor, resulting in the down-regulation of PLAGL2 downstream proteins hypoxia inducible factor and β-catenin. This study not only introduces the dimerization method to form novel compounds that will provide a new approach for drug design, but also suggests that PLAGL2 may be an effective target in tumor therapy.

High dilutions of a drug of COVID-19 origin show difference in ranks

High dilutions (HDs) of drugs, used in Homeopathy, are prepared in aqueous EtOH (ethanol) through serial dilution accompanying mechanical agitation or succussion, and are called potencies. The potencies from the rank 12 onwards are too dilute to contain any original drug molecules. Do the potency ranks show any difference from each other? Do serial dilution and succussion contribute to the difference in potency ranks? This study aims to address these two questions. The throat swab of a Covid-19 patient was preserved and diluted with aqueous EtOH 90% to prepare the mother tincture (MT) and five different potencies of Covid named Covidinum. These potencies and their solvent media were analysed by electronic and vibrational spectroscopy. Charge transfer (CT) and proton transfer interactions occur during preparation of the potencies. The FT-IR spectra of all the test samples after normalization show difference from each other with respect to O-H stretching and bending (v2) bands. Serial dilution and succussion contribute to the observed difference in ranks and CT interactions.

Complicated intermolecular interactions formed between organofluorine and drug target / 药学学报

Fluorinated compounds, which now make up 20%-25% of all marketed chemical drugs, are playing significant role and showing great potential in medicinal chemistry. Fluorine substitution is always utilized to change the physicochemical properties of the compounds to improve the ADME/T properties. In addition, fluorine substitution leads to improvement of the ligand binding affinity. With respect to molecular level, organofluorine can form various intermolecular interactions with the target proteins, e.g., hydrogen bond, halogen bond, C-F…π interaction, polar interaction and so on. These interactions display unique properties or nature due to the specificity of fluorine atom, which are at the center of attention. This paper reviews the related research background, followed by the research progress of hydrogen bond, halogen bond, C-F…π interaction, polar interaction and some other interactions involved organofluorine.

Raman spectroscopy shows difference in drugs at ultrahigh dilution prepared with stepwise mechanical agitation

OBJECTIVE: The present study aims at deciphering the nature of the water structure of two ultrahigh diluted (UHD) homeopathic drugs by Laser Raman Spectroscopy. METHOD: Two homeopathic drugs Sulphur and Natrum mur in three UHD 30cH, 200cH and 1000cH were selected for the study. Raman spectra of the drugs and their medium (90% ethanol) were obtained in the wave number region of 2600-3800 cm-1. The intensity ratio at vibration frequencies between 3200 and 3420 (R1) and that between 3620 and 3420 (R2) was calculated for each UHD as well as the control. RESULTS: Raman spectra shows differences in intensities in different UHDs and their control in the stretching vibrations of CH and OH groups. The three UHDs of each drug show an inverse relationship with respect to the R1 values. However, for R2 the relationship of UHD for each drug is positive. CONCLUSION: R1 provides information about the relative number of OH groups with strong and weak hydrogen bonds. R2 suggests the relative number of OH groups with broken and weak hydrogen bonds. Judged from R1 values the lower is the rank of UHD, the stronger is the H-bond of the OH groups. In the light of R2 values, the higher is the UHD rank the more abundant is the free OH groups. So, hydrogen bond strength and free OH groups together make an effective UHD rank relating to Sulphur and Natrum mur.

Raman spectroscopy reveals variation in free OH groups and hydrogen bond strength in ultrahigh dilutions

OBJECTIVE: To decipher the nature of water structure in two ultrahigh diluted (UHD) homeopathic drugs by Laser Raman Spectroscopy. METHOD: Two homeopathic drugs Calcarea carbonica (Calc.) and Sepia officinalis (Sep.) in 8cH, 202cH, and 1002cH and their diluent medium 90% ethanol in 8cH and 202cH were used in the present study. Laser Raman spectra of all the samples were obtained in the wave number region of 2400 – 4200 cm-1. The intensity ratio at vibration frequencies between 3200 and 3420 (R1) and that between 3620 and 3420 (R2) were calculated for each UHD of the samples. RESULTS: The spectra show a marked difference in intensities in the stretching vibrations of CH and OH groups of all the samples. R1 values for three UHDs of Calc. and Sep. show negative and positive relationships, respectively. In the case of R2 values, the relationship in three UHDs is 81002 for Calc., and 8> 202 < 1002 for Sep. In the case of control (ethanol UHDs) both R1 and R2 show a negative relationship. CONCLUSION: R1 denotes a relative number of OH groups with strong and weak hydrogen bonds. R2 indicates the relative number of OH groups with broken and weak H-bonds. Therefore, the UHDs of the two drugs and the control are different from each other with respect to hydrogen bond strength of OH groups and the number of free OH groups or non-hydrogen bonded water molecules.

Effect of hydrogen bond formation/replacement on solubility characteristics, gastric permeation and pharmacokinetics of curcumin by application of powder solution technology

The present research aimed to improve the dissolution rate and bioavailability of curcumin using the potential of liquisolid technology. Twelve drug-loaded liquisolid systems (LS-1 to LS-12) were prepared using different vehicles (PEG 200, PEG 400 and Tween 80) and curcumin concentrations in vehicle (40%, 50%, 60% and 70%,/). The carrier [microcrystalline cellulose (MCC) PH102] to coat (Aerosil) ratio was 20 in all formulations. The systems were screened for pre-compression properties before being compressed to liquisolid tablets (LT-1 to LT-12). Post compression tests anddissolution of LTs were conducted and the results compared with those obtained for a directly compressed tablet (DCT) made of curcumin, MCC PH102 and Aerosil. LTs exhibited higher cumulative drug release (CDR) than the DCT and the optimum formulation, LT-9 (made using Tween 80), was studied by powder XRD, DSC, SEM and FTIR.permeation of curcumin from LT-9 through goat gastrointestinal mucosa was significantly (<0.05) enhanced and its oral bioavailability was increased 18.6-fold in New Zealand rabbits.cytotoxicity (IC) of LT-9 towards NCL 87 cancer cells was 40.2 µmol/L substantiating its anticancer efficacy. Accelerated stability studies revealed insignificant effects of temperature and humidity on LT-9. In summary, solubility enhancement of curcumin in LTs produced significant improvements in its permeation and bioavailability.

Conformational study of N-methylated alanine peptides and design of Aẞ inhibitor.

N-Methylation increases the proteolytic stability of peptides and leads to improved pharmacological and increased nematicidal property against plant pathogens. In this study, the quantum mechanical and molecular dynamic simulation approaches were used to investigate conformational behavior of peptides containing only N-methylated alanine (NMeAla) residues and N-methylated alanine and alanine residues at alternate positions. The amide bond geometry was found to be trans and the poly NMeAla peptides were shown to populate in the helical structure without hydrogen bond with , values of ~ 0, 90˚ stabilized by carbonyl-carbonyl interactions. Molecular dynamic simulations in water/methanol revealed the formation of β-strand structure, irrespective of the starting geometry due to the interaction of solvent molecules with the carbonyl groups of peptide backbone. Analysis of simulation results as a function of time suggested that the opening of helical structure without hydrogen bond started from C-terminal. Conformational behavior of peptides containing N-MeAla and Ala was used to design Ab peptide inhibitor and the model tetrapeptide Ac-Ala-NMeAla-Ala-NHMe in the β-strand structure was shown to interact with the hydrophobic stretch of Aβ15-42 peptide.