Trimerization of Acetylene and Alkene:Rapid Access to Polyenes

Conjugated polyene motifs are ubiquitous in various natural products and functional molecules;however,their synthesis is very challenging because of the required lengthy and time-consuming processes.We herein report an efficient approach for the synthesis of(E,E)-trienes via cationic rhodium catalysis using acetylene and simple alkenes bearing diverse directing groups as the starting materials.The reaction featured high step economy,excellent functional group compatibility,and exclusive stereoselectivity.Various directing groups such as carbonyl,sulfone,phosphate,hydroxyl,and amino were compatible.Furthermore,the triene products allowed versatile elaborations,providing rapid and convenient access to several important bioactive molecules,including vitamin A,(+)-roxaticin,and other complex polyenes.Mechanistic experiments showed that the directing group on the alkene played a crucial role in the reaction.

气相色谱法测定多烯磷脂酰胆碱注射液中的苯甲醇

建立了多烯磷脂酰胆碱注射液中苯甲醇含量的测定方法。采用毛细管气相色谱法，以环己醇作为内标物，使用AT．SE-54毛细管色谱柱，程序升温，N2为载气，不分流进样模式，氢火焰离子化检测器（FID）检测。结果表明苯甲醇在0．01～20．0g／L范围内峰面积与内标峰面积的比值与其质量浓度呈良好的线性关系（r=0．9997），平均加样回收率为99．7％，相对标准偏差（RSD）为1．07％。该方法简便，准确，重现性好，精密度高，适用于多烯磷脂酰胆碱注射液中苯甲醇含量的测定，为同类药物的质量控制提供了实验依据。

Characterization and phylogenetic analysis of novel polyene type antimicrobial metabolite producing actinomycetes from marine sediments:Bay of Bengal India

Objective:To isolate and indentify the promising antimicrobial metabolite producing Streptomyces strains from marine sediment samples from Andraprudesh coast of India.Methods:Antagonistic aetinomycetes were isolated by starch casein agar medium and modified nutrient agar medium with 1%glucose used as a base for primary screening.Significant antimicrobial metabolite producing strains were selected and identified by using biochemical and 16S rDNA level.Minimum inhibitory concentrations of the organic extracts were done by using broth micro dilution method.Results:Among the 210 actinomyeetes,64.3%exhibited activity against Gram positive bacteria,48.5%showed activity towards Cram negative bacteria,38.8%exhibited both Cram positive and negative bacteria and 80.85%isolates revealed significant antifungal activity.However,five isolates AP-5,AP-18,AP-41 and AP-70 showed significant antimicrobial activity.The analysis of cell wall hydrolysates showed the presence of LL-diaminopimelic acid and glycine in all the isolates.Sequencing analysis indicated that the isolates shared 98.5%-99.8%sequence identity to the 16S rDNA gene sequences of the Streptomyces taxons.The antimicrobial substances were extracted using hexane and ethyl acetate from spent medium in which strains were cultivated at 30X for five days.The antimicrobial activity was assessed using broth micro dilution technique.Each of the culture extracts from these five strains showed a typical polyenelike property.The lowest minimum inhibitory concentrations of ethyl acetate extracts against Escherichia coli and Cumularia lunula were 67.5 and 125.0μg/mL,respectively.Conclusions:It can be concluded that hexane and ethyl acetate soluble extracellular products of novel isolates are effective against pathogenic bacteria and fungi.

FIBRED MAGNESIUM HYDROXIDE AND FLAME-RESISTANT POLYENE MATERIAL

The fibred magnesium hydroxide from the bracite was treated with a surface active agent. The modified fibred magnesium hydroxide as flame-retardant, boric acid, barium stearate, polydimethyl siloxane fluid, vinyltriethoxysilane as synergists of the flame-retardant were added to polyene resin. The flame-resistance polyene material prepared meets the requirements of EWCZ-6287-1. (Author abstract) 2 Refs.

Antifungalmycin,an antifungal macrolide from Streptomyces padanus 702

Two polyene macrolide antibiotics:antifungalmycin(1)and fungichromin(2)were isolated from the culture mycelia of Streptomyces padanus 702 via bioactivity-guided fractionation using various chromatographic procedures.Their structures were elucidated on the basis of spectral analysis,and 1 is a new polyene macrolide.Compounds 1 and 2 showed significant inhibition against Gibberella zeae with EC_(50)values of 26.71 and 2.21μg/mL,Fusicoccum sp.(plantain head blight)with EC_(50)values of 23.4 and 3.17μg/mL,Mucor ssp.8894 with EC_(50)values of 28.80 and 2.11μg/mL,Ustilaginoidea virens with EC_(50)values of 26.72 and 0.21μg/mL,respectively.This shows that the microbial secondary metabolites 1 and 2 have the potential to be developed as agricultural fungicides for use against G.zeae,Fusicoccum sp.,Mucor ssp.8894,and U.virens.

A polyene chain of canthaxanthin investigated by temperature-dependent resonance Raman spectra and density functional theory (DFT) calculations

We report on a temperature-dependent resonance Raman spectral characterization of the polyene chain of canthax- anthin. It is observed that all vibrational intensities of the polyene chain are inversely proportional to temperature, which is analyzed by the resonance Raman effect and the coherent weakly damped electron/lattice vibrations. The increase in intensity of the CC overtone/combination relative to the fundamental with temperature decreasing is detected and discussed in terms of electron/phonon coupling and the activation energy Uop. Moreover, the polyene chain studies using the density functional theory B3LYP/6-31 G＊ level reveal a prominent peak at 1525 cm-1 consisting of two closely spaced modes that are both dominated by C=C stretching coordinates of the polyene chain.

Screening and Purification of Natural Products from Actinomycetes that Induce a“Rounded”Morphological Phenotype in Fission Yeast

This study was designed to identify and investigate bioactive natural product compounds that alter the cellular shape of the fission yeast Schizosaccharomyces pombe and induce a“rounded”or“small”cellular morphological phenotype.Bioassays using a range of antifungal agents against a multidrug-sensitive fission yeast strain,SAK950 showed that many induced a“rounded”phenotype.We then investigated whether 46 of the actinomycete strains identified in our previous study as inducing a similar phenotype produced antifungal agents of similar classes.We show that five of the strains produced streptothricin and that 26 strains produced polyenes,including fungichromin,filipin and candicidin,the last of which was produced by 24 strains.A taxonomic study of the strains indicated that the majority of the candicidin only producers were Streptomyces hydrogenans and S.albidoflavus whilst those that additionally produced streptothricin were related to S.enissocaesilis.A follow-up study to investigate the natural products made by related strains indicated that they followed a similar pattern.The identification of several compounds from the actinomycete strains similar to the antifungal agents initially tested confirm the validity of an approach using the S.pombe morphological phenotype and actinomycete taxonomy as a predictive tool for natural product identification.

In Situ Resonance Raman Spectra of Organic Pigments in Momo Coral

In this study, Raman scattering measurements were obtained for momo corals covering their typical range of colors. Three different excitation wavelengths （785, 633, 514 nm） are used for the same samples at the same points. All the samples show the two major Raman features of polyenic compounds assigned to double carbon-carbon （C=C） stretching vibration at approximately 1 500 cm^-1 and single carbon-carbon （C-C） stretching vibration at approximately 1 130 cm^-1 bond stretching mode. These peaks are not detected in the corresponding white parts of momo corals. However, some changes in intensities, shape, and position of C=C stretching vibrations of the same point are observed by using different excitation wavelengths. The exact position of C-C stretching vibration of polyenic molecules depends strongly on the number of double bonds contained in their polyenic chain. In addition, the number of double bonds contained in the polyenic chains shows that different colors of the red momo coral are caused by different mixtures of polyenic compounds.

Effect of polyene phosphatidylcholine/ursodeoxycholic acid/ademetionine on pregnancy outcomes in intrahepatic cholestasis

BACKGROUND Intrahepatic cholestasis of pregnancy(ICP)is a liver disorder that occurs in pregnant women and can lead to a range of adverse pregnancy outcomes.The condition is typically marked by pruritus(itching)and elevated levels of liver enzymes and bile acids.The standard treatment for ICP has generally been ursodeoxycholic acid and ademetionine 1,4-butanedisulfonate,but the efficacy of this approach remains less than optimal.Recently,polyene phosphatidylcholine has emerged as a promising new therapeutic agent for ICP due to its potential hepatoprotective effects.AIM To evaluate the effect of polyene phosphatidylcholine/ursodeoxycholic acid/ademetionine 1,4-butanedisulfonate on bile acid levels,liver enzyme indices,and pregnancy outcomes in patients with ICP.METHODS From June 2020 to June 2021,600 patients with ICP who were diagnosed and treated at our hospital were recruited and assigned at a ratio of 1:1 via randomnumber table method to receive either ursodeoxycholic acid/ademetionine 1,4-butanedisulfonate(control group,n=300)or polyene phosphatidylcholine/ursodeoxycholic acid/ademetionine 1,4-butanedisulfonate(combined group,n=300).Outcome measures included bile acids levels,liver enzyme indices,and pregnancy outcomes.RESULTS Prior to treatment,no significant differences were observed between the two groups(P>0.05).Post-treatment,patients in both groups had significantly lower pruritus scores,but the triple-drug combination group had lower scores than the dual-drug combination group(P<0.05).The bile acid levels decreased significantly in both groups,but the decrease was more significant in the triple-drug group(P<0.05).The triple-drug group also exhibited a greater reduction in the levels of certain liver enzymes and a lower incidence of adverse pregnancy outcomes compared to the dual-drug group(P<0.05).CONCLUSION Polyene phosphatidylcholine/ursodeoxycholic acid/ademetionine 1,4-butanedisulfonate effectively relieves pruritus and reduces bile acid levels and liver enzyme indices in patients with ICP,providing a positive impact on pregnancy outcome and a high safety profile.Further clinical trials are required prior to clinical application.

Clinical efficacy of Qingre Quzhuo capsule in the treatment of non-alcoholic fatty liver disease

Background:To observe the clinical effect of Qingre Quzhuo capsule in the treatment of non-alcoholic fatty liver disease.Methods:90 patients with non-alcoholic fatty liver disease in our hospital from January 2021 to January 2022 were randomly divided into observation group and control group,45 cases in each group.All patients received routine lifestyle intervention and the control group received oral polyene phosphatidylcholine capsules 2 capsules/time(456 mg),three times daily;45 cases in the observation group were given Qingre Quzhuo capsule(Jiyao Z2017040,0.5 g/grain)2.5 g/time,3 times/day,for 12 weeks.The clinical efficacy,liver function,liver transient elastography controlled attenuation index value,lipid metabolism,oxidation and antioxidant indexes were compared between the two groups after treatment.Results:The observation indexes of the two groups after treatment were better than those before treatment(P<0.05).After treatment,the total effective rate of the observation group was higher than that of the control group.Lipid metabolism indexes and oxidation indexes were lower than those in the control group.All antioxidant indexes were higher than control group.The decrease of liver transient elastography controlled attenuation index value was better than that of the control group and the difference was statistically significant(P<0.05).There was no significant difference in the decrease of alanine aminotransferase between the observation group and the control group after treatment.The decrease of r-glutamyltransferase was statistically significant(P<0.05).Conclusion:Qingre Quzhuo capsule in the treatment of non-alcoholic fatty liver disease can improve liver function,regulate lipid metabolism indexes of patients,improve the antioxidant capacity of liver cells and improve the controlled attenuation index value of liver transient elastography.In addition,it is superior to polyene phosphatidylcholine in regulating lipid metabolism,antioxidant capacity and controlled attenuation index value of patients with non-alcoholic fatty liver disease which is safe and worthy of promotion.

由组合系数推导共轭体系的能级

通常由久期行列式求能量,本文则由组合系数来推导能级通式。由公式E_p=α+2βsum from(r-s)C_(pr)C_(ps)出发,代入链多烯和环多烯时LCAO-MO中原子轨道的组合系数C_(pi),导出了分子轨道ψ_p相应的能级通式,与其他方法得出的结果相同。

An unexpected generation of magnetically separable Se/Fe3O4 for catalytic degradation of polyene contaminants with molecular oxygen

Selenization of Fe2O3 with NaHSe led to Se/Fe3O4.The unexpected generation of Fe3O4 attributed to the reduction conditions of the reaction,and the resulted magnetic features of the material facilitated its separation in practical applications.Owning to the synergistic effect of Se with Fe,the material was especially active to catalyze the oxidative C=C scission using O2 as mild oxidant.The technique has been successfully applied in polyene degradation project,which is of profound practical values for the treatment of the polyene pigment pollution and may be applied in the food and pha rmaceutical industry.

HeI photoelectron spectroscopic (PES) studies of the electronic structure in ω-heterocycle a-cyano polyenic ethyl ester compounds

HeI photoelectron spectra of w-heterocycle a-cyano polyenic ethyl ester compounds (1-6) have been given in this paper. Assignment of the spectra is also done with the aid of HeI photoelectron spectroscopic (PES) results of smaller molecules which have similar atomic group to the molecules studied, and the aid of MNDO molecules orbital calculations. The lowest PES experimental ionization potentials (IPs in eV) of different molecules reduce gradually with the increasing number of ethylenic group. The -CO2C2H5 group can be only considered as a substituent.

HeI Photoelectron Spectroscopic Studies of Phenyl Polyenic Phenyl Ketone Compounds

The phenyl polyenic phenyl ketones (shown as below) belong to the forkedconjugative compounds.It is united, through an atom or a group, by three conjugated groups or three conju-gated bonds. Many compounds consisting of the carbonyl group and aromatic ringare typical forked conjugative compounds.

Fuzzy ta/2 symmetries of straight chain conjugate polyene molecules

On the basis of our recent studies on the molecular fuzzy point group symmetry,we further probe into the more complicated planar one-dimensional fuzzy periodic molecules-straight chain conjugate polyene.Except for the fuzzy translation transformation,the space transformation of the fuzzy screw rotation and the glide plane will be referred to.In addition,other fuzzy point symmetry transformation lain in the space transformation is discussed.Usually there is a correlation between the fuzzy symmetry characterization caused by the transition of the point symmetry elements and by certain space symmetry transformation.For the molecular orbital,the irreducible representation component is analyzed besides the membership function of the fuzzy symmetry transformation.Also,we inquire into the relativity between some molecular property and the fuzzy symmetry characterization.

HeⅠ Photoelectron Spectroscopic Study of α-Cyano co-Heterocyclic Polyenic Nitriles

Gas phase HeI photoelectron spectroscopy(UPS) yields a lot of information on the electronic structures, the conformations and the bonding characters of the studied molecules. Photoelectron spectra of some forked conjugative systems have been reported. And their experimental and theoretical basis on the rule of homologous linearity as well as molecular orbital characters of carbonyl group as a separative group have also been pointed out. In this note the UPS studies on some α-cyano ω-heterocyclic polyenic nitriles

STRUCTURAL EFFECT IN FORKED CONJUGATIVE SYSTEMS——BIFURCATION-TYPE OF FORKED POLYENIC NITRILES,CARBOXYLIC ACIDS AND ESTERS

Five homologous series of bifurcate systems of aliphatic and aromatic polyenic cyano and carboxylic compounds have been prepared and studied. The electronic absorption spectra forthe series and the NMR chemical shifts for the methyl-, methylene- and beta-protons havebeen found to conform very well to the rule of homologous linearity. The mass spectra forthe α-cyano polyenic ester series show strong peaks for the fragments of M-COOEt but noneof M-CN, indicating that the CN group seems to be in stronger conjugation with the poly-enic chain than the COOEt group does. In all the forked series studided, a red shift in electronic spectra is brought about upon the introduction of an electron-attractive branching group, just like the case of introducing an electron-repelling substituent. This has been taken as an indication of the predominance of themolecular integrality over the group characteristics. By means of the method of similar triangles between a homologous line for a linearseries and that for the corresponding forked compounds, the equivalent △Ns for a branching group may be calculated with accuracy. Based on the value of this equivalent, the substituentnature of the structural effect of the branching group has been inferred. The electronic absorption maxima for four series of the forked compounds have been cal-culated by means of the extended homologous equation for the corresponding linear compounds.With an appropriate correction for the positional effect of the substituent equivalent, the cal-culated wavelengths agree generally with experimental data within ± 7nm.

Genome mining reveals the biosynthetic potential of the marinederived strain Streptomyces marokkonensis M10

Marine streptomycetes are rich sources of natural products with novel structures and interesting biological activities,and genome mining of marine streptomycetes facilitates rapid discovery of their useful products.In this study,a marine-derived Streptomyces sp.M10 was revealed to share a 99.02%16S rDNA sequence identity with that of Streptomyces marokkonensis Ap1T,and was thus named S.marokkonensis M10.To further evaluate its biosynthetic potential,the 7,207,169 bps of S.marokkonensis M10 genome was sequenced.Genomic sequence analysis for potential secondary metaboliteassociated gene clusters led to the identification of at least three polyketide synthases(PKSs),six non-ribosomal peptide synthases(NRPSs),one hybrid NRPS-PKS,two lantibiotic and five terpene biosynthetic gene clusters.One type I PKS gene cluster was revealed to share high nucleotide similarity with the candicidin/FR008 gene cluster,indicating the capacity of this microorganism to produce polyene macrolides.This assumption was further verified by isolation of two polyene family compounds PF1 and PF2,which have the characteristic UV adsorption at 269,278,290 nm(PF1)and 363,386 and 408 nm(PF2),respectively.S.marokkonensis M10 is therefore a new source of polyene metabolites.Further studies on S.marokkonensis M10 will provide more insights into natural product biosynthesis potential of related streptomycetes.This is also the first report to describe the genome sequence of S.marokkonensis-related strain.

THE MASS SPECTRA OF AROMATIC CONJUGATED POLYENIC ACID,METHYL BENZOATE,METHYL PHENYL KETONE,BENZONITRILE AND ANILINE AND THEIR QUANTUM CHEMICAL CALCULATIONS

A quantitative interpretation of mass spectra of complex organic compounds so far is notvery perfect and needs some further investigation. In this paper a mechanism of cleft-rate-determining-steps of aromatic conjugated polyenic acid, methyl benzoate, methyl phenyl ketone,benzonitrile and aniline is proposed, and various quantum parameters of molecular ions ofaromatic conjugated polyenic compounds, together with their framents are calculated bymeans of CNDO/2 method. Through the process of calculation, the peak-height of mass spectracan be quantitatively interpreted, which means that the main factors which influence the cleftforms of simple cleavage of mass spectra of conjugated compounds given by the authorsmight be true to some extent.

Ynamide Protonation-Initiated Cis-Selective Polyene Cyclization and Reaction Mechanism

The diastereoselectivity of conventional polyene cyclization reactions is highly dependent on the configuration of the internal alkenes,where E-poly enes provide trans-decalins,while Z-polyenes offer cis-decalins.Although polyene cyclization has evolved into a reliable and widely used strategy for the construction of trans-decalin frameworks of terpene and steroid natural products,its application for cis-decalin framework is extremely challenging.