[An investigation on professional performance of optometric refraction in spectacles stores in Anyang city of Henan Province].

Objective: To investigate the methods of optometric refraction adopted for adolescents in spectacles stores in Anyang city of Henan Province and the professional performance of optometric refraction. Methods: Cross-sectional study. Maps and yellow pages were used to collect the information of 131 spectacles stores in Anyang city. A questionnaire was used to investigate spectacles stores that had optometry equipment and can provide refraction prescription and spectacles in this city. The questionnaire covered (1) the process of optometric refraction, including whether cycloplegic refraction was conducted for adolescents and children if it was their first-time optometry and the type of cycloplegics,and (2) the opticians' knowledge on optometric refraction for adolescents and children, such as necessity of cycloplegic refraction for adolescents and children and age cut-offs. According to whether they used a comprehensive refractometer, the optometry methods were divided into conventional optometry and medical optometry. Results: Of 131 spectacles stores in Anyang city, 127 were enrolled. A total of 127 questionnaires were distributed and returned with an effective rate of 100%. Conventional optometric refraction was performed in 53 stores (41.73%), and medical optometric refraction was performed in 74 stores (58.27%). Cycloplegic refraction was conducted in only 4 spectacles stores (3.15%) for adolescents and children upon their first-time optometry. The fogging method of refraction was adopted in 31 stores (24.41%), while optometric refraction was directly conducted in 92 stores (72.44%) without controlling accommodation. As for the use of cycloplegia at initial optometric refraction of children, cycloplegia was objected to in 4 stores,and thought to be no need in 28 stores including 6 stores in which the fogging method was used to replace cycloplegia. In 68 stores, cycloplegia was performed if wanted, or children could go to a hospital for it. In 12 stores, the use of cycloplegics was determined by children's vision and diopters. In 5 stores, children were suggested to go to a hospital for cycloplegic refraction. Cycloplegic refraction was required in only 4 stores. As to the age cut-offs of cycloplegic refraction, 6 years old, 12 years old, and 18 years old were considered as the boundary in 7 stores, 33 stores, and 9 stores, respectively.In 11 stores, age was only considered for amblyopia and hyperopia, and in 67 stores, it was not realized. Conclusions: Cycloplegic refraction was found to be conducted for adolescents and children in only 3% of the spectacles stores in Anyang city. Moreover, most of the spectacles store opticians did not support to use cycloplegia before optometric refraction for adolescents and children and lacked knowledge on the age cut-offs of cycloplegic refraction.Standardized training of cycloplegic refraction should be further strengthened. (Chin J Ophthalmol, 2019, 55: 576-581).

Fading and showing mechanisms of ancient color relics based on light scattering induced by particles.

Fading and showing mechanisms of ancient color paintings based on light scattering induced by particles were proposed. To confirm the mechanisms, simulated and application experiments were carried out to restore an ancient blurred color painting. Loading TiO2 particles (500-1000 nm) onto a piece of colored paper could result in blurring of the color of the paper, which is attributed to light scattering caused by air voids between the particles. Filling air voids with ionic liquid (a non-volatile solution with a high refractive index) could highlight the color by reducing scattering. These results were experimentally testified by the combination of a fluorescence probe and multi-angle reflectance spectra, in which scattering decreased the incident optical path in the painting layer while the incident optical path was increased by filling the air voids with ionic liquid. As a practical example, the proposed method was applied to highlight an ancient Chinese painting with blurred color. This investigation is very useful to restore faded color paintings.

1H-NMR signal assignments and secondary structure analysis of martentoxin.

Martentoxin is a peptide of 37 amino acid residues purified from the venom of the Chinese scorpion Buthus martensi Karch, which has been demonstrated to be an inhibitor of voltage-dependent sodium channel and voltage-dependent delayed rectifier potassium channel. To elucidate the molecular mechanism of this interaction, the structure of martentoxin was studied by 2D-NMR. The secondary structure of martentoxin consists of a triple-stranded beta-sheet connected to a alpha-helical structure. This helix encompasses 10 residues from Ser11 to Lys20. The three strands of beta-sheet probably comprise residues Gly2-Asp5, Q27-N30 and Glu33-Cys36, Cys30-Asn33 with a type I'beta turn centered on Asn31-Asn32. The results indicate that martentoxin possesses the conserved beta alpha beta beta structure of all the potassium channel toxins.

Recent progress in structure activity relationship and mechanistic studies of taxol analogues.

Structure activity relationship (SAR) and mechanism of paclitaxel and its analogues in recent years are discussed in the following areas: SAR of paclitaxel analogues toward "normal" and multi-drug resistance tumors; paclitaxel prodrugs with improved water solubitily and specificity; mechanism of paclitaxel related to tubulin binding and quest for its pharmacophore.

Purification and characterization of a new peptide with analgesic effect from the scorpion Buthus martensi Karch.

Anew peptide, designated as Buthus martensi Karch (BmK) AngM1, with an isoelectric point (pI) of 5.8 was purified and characterized from the venom of Buthus martensi Karch. The molecular mass was calculated as 7040.5 Da from multiple-charged ions by elelctrospray ionization mass spectroscopy (ESI/MS). The complete amino acid sequence of BmK AngM1 of 64 amino acid residues was determined by automatic sequencing of N-terminal part of the native peptide and the fragments of reduced and S-carboxymethylated (RCM)-peptide degraded by Staphylococcus aureaus V(8) protease and TPCK(N-p-Tosyl-L-phenylalanine chloromethyl ketone)-treated trypsin. Bioactivity tested using mouse-twisting model showed an evident analgesic effect with 63.0% (P < 0.001) inhibition efficiency at the dose of 0.8 mg/kg, but the LD(50) was larger than 50 mg/kg. Electrophysiological studies showed that BmK AngM1 at the concentration of 1 microm obviously inhibit voltage-dependent Na(+) current (I(Na)) and voltage-dependent delayed rectifier K(+) current (I(K)) but had no effects on transient K(+) current.

Purification, characterization of two peptides from Buthus martensi Karch.

A new peptide named Martentoxin I and an analogue Martentoxin were purified and characterized from the venom of Buthus martensi Karch. Martentoxin I consisted of 36 amino acid residues with molecular mass as 3908.0 Da determined by matrix-assisted laser desorption ionization time-of-flight-MS. The amino acid sequence was determined as GLIDVKCFASSECWTACKKVTGSGQGKCQNNQCRCY by Edman degradation. Martentoxin consisted of 37 amino acid residues with a molecular mass as 4055.3 Da and it showed highly sequence identity to Martentoxin I as FGLIDVKCFASSECWTACKKVTGSGQGKCQNNQCRCY. Estimation from circular dichroism spectra indicated Martentoxin I owned 18.0% alpha-helix, 53.0% beta-sheet structure and 3.9% turn while Martentoxin contained 13.3% alpha-helix, 64.3% beta-sheet structure and 1.1% turn. The toxicity assay showed both peptides had no toxic effects on mice up to the dose of 10 mg/kg. Electrophysiological studies showed that Martentoxin I and Martentoxin at the concentration of 1 microm significantly inhibited voltage-dependent Na+ current (INa) and voltage-dependent delayed rectifier K+ current (IK) but had no effects on transient K+ current (IA). Both interactions with Na+ and K+ channels were irreversible.

Stereoselective total synthesis of chrysanthemol.

Chrysanthemol (1), a trans-eudesmane type sesquiterpene from Chrysanthemum indicum L., possesses certain anti-inflammatory activity. Its total synthesis was approached from two alternative routes and finally accomplished in ten steps from R-(+)-carvone via alpha-eudesmol (10) as the key intermediate. The overall yield is 2.4% and the spectral data of the synthetic target compound were identical with that of natural chrysanthemol (1). Seven intermediary compounds were tested for inhibitory effects on the carragenan-induced swelling of mouse paw but demonstrated no obvious activities.

[Synthesis and vasodilative activities of alpha-phenylcinnamide].

AIM: To search for compounds having strong vasodilating effect. METHODS AND RESULTS: The mixed anhydride and alpha-phenylcinnamyl halide were used. Twenty-two alpha-phenylcinnamide derivatives were synthesized. The strutures were elucidated on the basis of MS and 1HNMR. Compounds 1-22 are new compounds. CONCLUSION: Vasodilative activity assays were conducted for the target compounds and the results indicated that several compounds (3, 9 and 11) demonstrated superior pharmacological profiles to the lead compound, among which compound 11 was further evaluated and found to be indicative of potential KCO activity. Preliminary SAR of alpha-phenylcinnamides was discussed herein.

[Synthesis of triphenylethylene with aliphatic cyclic moiety and its antagonism on estrogen receptor].

AIM: In order to improve the biological activity and reduce the side effects and toxicity, a series of novel estrogen receptor antagonists were designed. METHODS: The key triphenylethylene intermediates were obtained by the McMurry reaction. The target compounds were prepared by etherification. The binding affinities of the target compounds for the estrogen receptor in rat uterine cytosol were measured by a competitive binding assay and their estrogen agonistic/antagonistic properties were investigated in the 3-day uterine weight assay in the immature rats. RESULTS: Thirty-five new compounds have been synthesized and their geometric configuration were determined by X-ray crystallography and 1HNMR spectral data. CONCLUSION: All of the test compounds showed affinity for the estrogen receptor (IC50 < 10(-6) mol.L-1), especially compound 35 with IC50 1.07 x 10(-8) mol.L-1. Some compounds are antagonists, inhibiting uterus growth; others are agonists, promoting uterus growth. Compounds 14 and 27 are superior antagonists to tamoxifen.

Structural chemistry and biological activities of natural products from Chinese herbal medicines.

This is a brief account of recent developments (1978-1994) in natural product chemistry and bioactivity related to Chinese herbal medicine. In the period covered, more than thousand chemically new constituents were isolated and their structures elucidated. We have presented most of the structural formulae for the sake of clarity, along with passing mentions of pertinent biological activities. The isolates were grouped under different headings according to structure types.

[Synthesis and biological activity of tyrosine protein kinase inhibitors].

Four classes of 25 tyrosine protein kinase (TPK) inhibitors were designed and synthesized. Compounds 1-10 were tested to inhibit TPK of HL-60 leukemia cell using 32P-ATP method, and some of them exhibit evident inhibitory activities. Their structure-activity relationship is similar to that of TPK inhibitors reported in literatures. Compounds 11-25 were tested to inhibit TPK of normal rat spleen cell using ELISA method and their SAR is different from that using 32P-ATP method.

[Chemical investigation of genus Hedyotis. II. Isolation and identification of iridoids from Hedyotis chrysotricha].

Many species of genus Hedyotis (Rubiaceae) were used as folk medicine for treatment of cold, inflammation, cancer and etc. in China. The alcoholic extract of the whole plant of H. chrysotricha showed good hepatoprotective effects. From the alcoholic extract ten iridoids were isolated and their structures were elucidated as: asperuloside (1), scandoside methyl ester (2), asperulosidic acid (3), deacetyl asperulosidic acid (4), loganin (5), deacetyl asperuloside (6), acetyl scandoside methyl ester (7), 6 beta-hydroxy-genipin (8) and two new compounds named hedyoside (9) and 6'-acetylasperuloside (10), by means of chemical and spectral methods.

[The structure correction of villosolside].

The crystal structure of villosolside was determined by X-ray diffraction, which led to some stereochemical amendment of the structure proposed in the article by Xu CJ et al. in Acta Pharm Sin 1985, 20:652.

Bicyclic taxoids from needles of Taxus chinensis.

A new bicyclic taxoid, 5-deacetyltaxachitriene B (2) together with a known bicyclic taxoid (1) were isolated from needles of Taxus chinensis. Spectral characteristics for these bicyclic taxoids were discussed.

[New diterpenoids, isodoternifolins A and B, from Isodon ternifolius].

Two new diterpenoids, named isodoternifolin A and B, together with seven known compounds were isolated from the ethanol extract of dried stems and leaves of Isodon ternifolius (D. Don) Kudo. Their structures were determined as 7 beta-hydroxy-6 beta, 11 alpha, 15 beta-triacetoxy-7 alpha, 20-epoxyentkaur-16-ene (1) and 6 beta, 7 beta, 15 beta-trihydroxy-11 alpha-acetoxy-7 alpha, 20-epoxy-entkaur-16-ene (2) by chemical and spectral evidence.

Rearranged taxoids from Taxus yunnanensis.

Two rearranged 2(3-->20)abeotaxanes were isolated from the leaves and stems of Taxus yunnanensis, and designated as taxin B and 2-deacetyltaxin B. The structure of taxin B with a unique 6/10/6 skeleton was deduced on the basis of 1H-NMR, 13C-NMR, 1H-1H COSY, DEPT, NOE, and mass spectra and confirmed by X-ray crystallographic analysis. The structure of 2-deacetyltaxin B is elucidated by analog.

Triterpenoid saponins from the bark of Nothopanax davidii.

Three new triterpenoid saponins were isolated from the alcoholic extract of the bark of Nothopanax davidii. Their structures have been determined on the basis of spectral and chemical data as 3-O-alpha-(4'-O-acetyl)-L-arabinopyranosyl-3 beta-hydroxyolean-12-ene- 28,29-dioic acid-28-O-[alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl (1-->6)-beta-D-glucopyranosyl]ester, named yiyeliangwanoside IX; 3-O-alpha-(2'-O-acetyl)-L-arabinopyranosyl-3 beta-hydroxyolean-12-ene-28,29- dioic acid-28-O-[alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)- beta-D-glucopyranosyl] ester, named yiyeliangwanoside X; and 3-O-beta-d-xylopyranosyl-3 beta-hydroxyolean-12-ene-28,29-dioic acid-28-O-[alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)-b eta-D - glucopyranosyl] ester, named yiyeliangwanoside XI.