Photo-induced Electron Transfer Between Hypocrellins and BNAH

1 Introduction Much research work has been done on the mechanism of photo-induced reduction of quinone dyes by electron donors with visible light. Two ways to obtain the net two-electron reduction product QH^- bave been proposed. One is the direct two-electron transfer (electron-proton-electron transfer) within the complex and the other is the disproportionatioh of the semiquinone radical QH·formed by one-electron transfer.

Raman spectroscopic study of DNA after photosensitive damage caused by hypocrellins A and B

Laser Raman spectroscopy provided the direct evidence for microcosmic photodamage in space structure of DNA molecule. When photosensitive damage was made to space structure of calf thymus DNA by hypocrellins A and B, the Raman characteristic frequencies and the intensities of the bands assigned to various groups of the components of DNA (phosphate backbone deoxyribose and four bases) changed at various degrees. There were not only the strand breakage, but also the breakage of some H bonds and disruption of vertical base base stacking interactions. The photosensitive damage of hypocrellin B on DNA was stronger than that of hypocrellin A on DNA.

Hypocrellin A通过ROS/JNK通路促进瘢痕疙瘩成纤维细胞凋亡的作用及机制

目的:探索Hypocrellin A(HA)通过活性氧簇(ROS)/c-Jun氨基末端激酶(JNK)通路促进瘢痕疙瘩成纤维细胞凋亡的作用及机制。方法:原代培养KFs并进行传代,第3代KFs分为对照组、不同剂量HA组(0.125、0.25、0.5、1.0μmol/L HA处理)、HA+乙酰半胱氨酸(NAC)组(1.0μmol/L HA+1.0 mmol/L NAC处理)。检测细胞增殖的光密度OD450,凋亡率,胶原代谢指标I型胶原(Col-I)、α-平滑肌肌动蛋白(α-SMA)、纤维连接蛋白(FN)、氧化应激指标丙二醛(MDA)、超氧化物歧化酶(SOD)、总抗氧化力(T-AOC)及ROS的含量,内质网应激标志物GRP78、p-IRE-1及ROS/JNK通路中p-JNK、cleaved caspase-3的表达水平。结果:不同剂量HA组的OD450、Col-I、α-SMA、FN、SOD、T-AOC的含量均低于对照组,凋亡率、MDA、ROS含量及GRP78、p-IRE-1、p-JNK、cleaved caspase-3的表达水平均高于对照组(P<0.05)且HA剂量越高,上述指标的变化越显著;HA+NAC组的OD450、Col-I、α-SMA、FN、SOD、T-AOC的含量均高于1.0μmol/L HA组,凋亡率、MDA、ROS含量及GRP78、p-IRE-1、p-JNK、cleaved caspase-3的表达水平均低于1.0μmol/L HA(P<0.05)。结论:HA通过促进KFs凋亡,这一作用与激活ROS/JNK通路介导的氧化应激和内质网应激有关。

Hypocrellin A与二苄胺和N-甲基苄胺的光化学反应

为了探讨HypocrellinA (HA)与胺基衍生物反应的自由基形成机制 ,我们采用ESR谱分别研究了HA与二苄胺 (DBA)和N 甲基苄胺 (NMBA)的光化学反应 .在含胺类物质和溶解氧的溶剂系统下 ,可见光照射HA激发成HA ,然后将溶解氧转变成1O2 ,1O2 诱导DBA或NMBA的氯仿溶液都能产生半醌自由基和氮氧自由基 .氮氧自由基的信号强度随光照时间的增加而减弱 ,而半醌自由基的信号强度随光照时间的增加而增强 ,氮氧自由基的含量与光照产生的半醌自由基成反比 .在除氧条件下 ,光照含HA和DBA的氯仿溶液体系时 ,半醌自由基是主要的自由基 .结果表明 ,在有氧的氯仿溶液中 。

Drug-delivery and multifunction possibilities of hypocrellin photosensitizers

Photodynamic therapy(PDT)has been a routine treatment of tumors and some microvascular diseases,but clinically available photosensitizers are still scarce.Among all kinds of photo-sensitizers,hypocellins possess the most characteristics of ideal photosensitizers,such as,high photo-activity but low dark toxicity,fast clearance from tssues.This review is focused on two main topics,drug-delivery problem of hypocrellins and how the environment-sensitive fluorescence of bypecrellins was used for recognition of various biomolecules.Drug-delivery of hypocrellins was mainly achieved in two strategies一preparing the drugdelivery vehicles and finding quantitatively amphiphilic derivatives.Hypocrellin fAuorescence originated from the intramolecular proton transfer is very distinct from other kinds of photosensitizers.Recently,it was proved that quan-titative hypocrellin ftuorescence could not only reoognize various biomolecules,including proteins,polysaocharides and lipids,but also distinguish the specific binding from nonspedifie binding with some kind of biomolecules.Meantime,hypocrellin fluorescence was pH sensitive.It is known that tumor cells or tses have the features of a large amount of lipid,neonatal collagen,over expression of polysaccharides,and lower pH values compared to normal tissues.According to the relative but not absolute specifcity,further studies on quantitative recognition of various biomolecules at a cellular level,may find a new clue to treat tumors by joint usage of photodynamic diagnosis(PDD)and PDT.

Synthesis and Properties of An Aminated hypocrellin B

A new aminated-perylenequinone derivative 2 was synthesized by the reaction of 1 (hypocrellin B) with 6-aminohexanoic-acid. The structure of 2 was identified by UV-Vis, MS, IR and H-1-NMR. Thc amphiphility spectrum and photochemical properties of 2 were reported.

Apoptotic Effects of Hypocrellin A on HeLa Cells

Hypocrellin A（ HA）, a photosensitive perylenequinone compound of Hypocrella bambusae, inhibited the proliferation of several tumor cell lines. Human cervical cancer cells, HeLa ceils, were used as a model to elucidate the molecular mechanisms of HA-induced tumor cell death. The results show that HA can induce the oligonucleosomal fragmentation of DNA in HeLa cells and also can increase the expression of apoptosis inducer Bax mRNA and that it decreases the expression of apoptosis suppressor, Bcl-2 mRNA, in mitochondria. It can be concluded from the data that HA-induced apoptosis is related to the balance between Bcl-2 and Bax gene expressions.

Synthesis of a hypocrellin B-polyamide conjugate as DNA-targeting photosensitizer

A new hypocrellin B （HB） derivative bearing a bispyrrolecarboxamide-containing side chain was synthesized, which presents improved absorptivity in phototherapeufic window than HB and affinity feature towards dsDNA.

Interaction of Hypocrellin B or Mono-cysteine Substituted Hypocrellin B with CT-DNA by Spectral Methods

The interaction of the anticancer drug hypocrellin B (HB) or the mono-cysteine substituted hypocrellin B (MCHB) and calf thymus deoxyribonucleic acid (CT-DNA) has been investigated using spectral methods. The results of UV-visible spectra show that the HB and MCHB could intercalate into the base-stacking domain of the CT-DNA double helix. The studies of fluorescence spectra and circular dichroism(CD) spectra also support the interacalation mechanism.

Study on the Singlet and Triplet StateElectron Transfer between Hypocrellin A and Aromatic Amines in Solvents of Various Polarity

In this paper, the singlet and triplet state electron transfer processes between hypocrellin A(HA) and aromatic amines in solvents of various polarity have been studied by fluorescence and time-resolved transient absorption spectra. The results show,in.polar solvent, the quenching of HA fluorescence by aromatic amines results in Stern-Volmer plot, the investigation of transient absorption indicated that triplet-state electron transfer process from 3HA to the ground-state of amines occured, and the wines of the singlet and triplet state electron transfer rate constant were calculated, however in weak polar solvent, only the triplet-triplet absorption of HA was observed.

High Efficiency Hypocrellin Production by a Novel Mutant Isolated from Shiraia bambusicola

The fungus Shiraia bambusicola GZ19 M1 is biotechnologically important due to its ability to biosynthesis the pigment hypocrellins.Results showed that ethyl methane sulfonate( EMS) was effective mutagenic agent for strain and potentially produced large numbers of random mutations broadly and uniformly over the whole genome to generate unique strains. Wild-type cultures of S. bambusicola GZ19 were subjected to EMS( 80 mM) induction targeted at approximately 20% spores' survival. When surviving spores were selected in sufficient numbers and cultured on PDA medium for 7 d at 26℃,five novel mutagenized S. bambusicola strains were obtained. A mutant GZ19 M1 that exhibited an activity of more than two times over the wild strain was obtained. Also,batch experiments were carried out to achieve the suitable conditions for hypocrellin. Glucose and rice extract were the most favorable carbon and nitrogen sources for hypocrellin production by submerged culture of S. bambusicola GZ19 M1,and initial glucose and rice extract concentrations were at 35 and 250 g/L,respectively. The optimal surfactant were found to be 0. 008 V/V Tween 80,it was added into cultivation medium at 24 h. Hypocrellin concentration reached 498. 89 mg/L under optimal nutritional conditions,an increment of about 8. 70 times of hypocrellins production was observed compared with that of in non-optimized medium by the wild strain.

Preparation of hypocrellin B nanoparticlesfor photodynamic therapy

OBJECTIVE To prepare hypocrellin B-loaded apoferritin nanoparticles(HB-AFT NPs)for photodynamic therapy on tumor.METHODS HB-AFT NPs were prepared by taking advantage of the reversibleunfolding and refolding character of apoferritin in different pH environments.The photophysical and photobiological properties of hypocrellin B-loaded apoferritin were measured.RESULETS HB molecules were successfully encapsulated within apoferritincavity.HB-AFT-NPs exhibited higher ROS productionthan free HB.Additionally,phototoxicity of HB-AFT NPs to MDA-MB-231 cells was significantly improved as compared to free HB.CONCLUSION Together these results demonstrate that hypocrellin B-loaded apoferritin might be a potential nanoscale photosensitizer.

从天然和传统药物中发展光动力和声动力药物(英文)

Malignant tumors and infectious diseases are two main threats to human beings.Photodynamic therapy(PDT)is an effective approach to treat malignancies and infections through the generation of reactive oxygen species(ROS)of a non-toxic photodynamic drug(photosensitizing agent)upon light irradiation.PDT shows promising in treating areas where light can reach,for example,skin and cavities.To treat the problems on deep tissues,much evidence has accumulated in recent years suggesting that sonodynamic therapy(SDT),which eradicates malignant or infectious cells by ROS produced from the interaction of ultrasound energy and sonodynamic drug(sonosensitizing agent),has potential in treating diseases in deep tissues because ultrasound energy has deeper tissue penetration than light energy.Natural products are a valuable source for developing novel drugs.In recent years,we are focusing on developing novel and naturally occurring photodynamic and sonodynamic agents.We have found some active components from natural products,for example,curcumin and hypocrellin,have not only photodynamic activity and also sonodynamic activity in killing bacterial and tumor cells.This talk will briefly introduce two new technologies including photodynamic and sonodynamic therapy,and highlight the recent development in photodynamic and sonodynamic drugs from natural products or traditional Chinese medicines.Chemical modifications of the active compounds have also been attempted to achieve better results.

Effect of sonodynamic action of hypocrellin B on biofilm-producing Enterococcus faecalis

OBJECTIVE To investigate the effect of sonodynamic action on biofilm-producing Enterococcus faecalis using hypocrellin B from a natural product Hypocrella bambuase as a sensitizer.METHODS The uptake of hypocrellin B in biofilm-producing Enterococcus faecalis was measured using the fluorescent analysis method.After the combined treatment of hypocrellin B and ultrasound,the growth of biofilm-producing Enterococcus faecalis was measured using the colony counting method,the membrane integrity was detected using a flow cytometric analysis with propidium iodide staining.Chromosomal DNA of bacteria was analysed using apulsed-field gel electrophoresis(PFGE).RESULTS The uptake of hypocrellin B in biofilm-producing Enterocuccus faecalis reached a high peak at the 20 min incubation.After the combined treatment of hypocrellin B,the growth of biofilm-producing Enterocuccus faecalis significantly descreased and membrane integrity was remarkably damaged.However,no remarkable change in bacterial DNA was found.CONCLUSION Sonodynamic action of hypocrellin B had significant killing activity on Enterocuccus faecalis.

Killing effect of the combined treatment of ultrasound and hypocrellin B on Candidaalbicans

OBJECTIVE To investigate the killing effect of the combined treatment of ultrasound and hypocrellin B,an active component isolated from a natural product Hypocrella bambuase,on Candida albicans.METHODS At first,Candida albicans are incubated with hypcrellin B and the uptake of hypocrellin B in Candida albicans was determined using fluorescence intensity analysis.And then the sensitized Candida albicans were exposed to low-intensity of ultrasound.After the combined treatment of ultrasound and hypocellin B,the growth of Candida albicans was evaluated using the colony counting method,and membrane integrity of Candida albicans was also analyzed by a flow cytometry with propidium iodide staining.RESULTS Hypocrellin B was fast absorbed by candida albicans.The growth of candida albicans was more significantly inhibited by the combined treatment of ultrasound and hypocrellin B than the controls(P<0.05).The more marked damages to membrane integrity were found in the combined treatment than the controls(P<0.05).CONCLUSION The combined treatment of ultrasound and hypocrellin B had significant killing effect on Candida albicans,indicating sonodynamic therapy with hypocrellin B from natural product might be a potential approach for combating fungal infections.

Volatiles of Shiraia fruiting body-associated Pseudomonas putida No.24 stimulate fungal hypocrellin production

Hypocrellins are major bioactive perylenequinones from Shiraia fruiting bodies and have been developed as efficient photosensitizers for photodynamic therapy.Pseudomonas is the second dominant genus inside Shiraia fruiting bodies,but with less known actions on the host fungus.In this work,the effects of bacterial volatiles from the Shiraia-associated Pseudomonas on fungal hypocrellin production were investigated.Pseudomonas putida No.24 was the most active to promote significantly accumulation of Shiraia perylenequinones including hypocrellin A(HA),HC,elsinochrome A(EA)and EC.Headspace analysis of the emitted volatiles revealed dimethyl disulfide as one of active compounds to promote fungal hypocrellin production.The bacterial volatiles induced an apoptosis in Shiraia hyphal cell,which was associated with the generation of reactive oxygen species(ROS).ROS generation was proved to mediate the volatile-induced membrane permeability and up-regulation of gene expressions for hypocrellin biosynthesis.In the submerged volatile co-culture,the bacterial volatiles stimulated not only HA content in mycelia,but also HA secretion into the medium,leading to the enhanced HA production to 249.85 mg/L,about 2.07-fold over the control.This is the first report on the regulation of Pseudomonas volatiles on fungal perylenequinone production.These findings could be helpful to understand the roles of bacterial volatiles in fruiting bodies and also provide new elicitation method using bacterial volatiles to stimulate fungal secondary metabolite production.

High-Throughput Drug Screening on Borrelia garinii and Borrelia afzelii Identified Hypocrellin A as an Active Drug Candidate Against Borrelia Species

Lyme disease(LD)is a tick-transmitted infection caused by Borrelia burgdorferi sensu lato species,which include B.burgdorferi,Borrelia afzelii and Borrelia garinii.The majority of patients with early LD can be cured by the standard treatment,yet some still suffer from posttreatment LD syndrome.The presence of Borrelia persisters has been proposed as a contributing factor,because they cannot be completely eradicated by the currently used antibiotics for LD.Finding new pharmaceuticals targeting Borrelia persisters is crucial for developing more effective treatments.Here,we first confirmed the existence of persisters in B.garinii and B.afzelii cultures and then conducted a high-throughput screening of a customdrug library against persister-rich stationary-phase B.garinii and B.afzelii cultures.Among 2427 compounds screened,hypocrellin A(HA),anthracycline class of drugs and topical antibiotics along with some other natural compounds were identified to have strong potential for killing persisters of B.garinii and B.afzelii.HA was the most active anti-Borrelia compound,capable of eradicating stationary-phase Borrelia persisters,in particular when combined with doxycycline and/or ceftriaxone.Liposoluble antioxidant vitamin E was found to antagonize the activity of HA,indicating HA’s target is the cell membrane where HA triggers the generation of reactive oxygen species in the presence of light.HA was found to have distinct bactericidal activity against Borrelia species but had poor or no activity against gram-positive and gram-negative bacteria.Identification of the abovementioned drug candidates may help develop more effective therapies for LD.

Photophysics,photochemistry and photobiology of hypocrel-lin photosensitizers

Hypocrellins are novel photosensitizers from China, which are demonstrated to have significant anti-tumor and anti-virus activity and to be potential photo-dynamic therapy (PDT) agents. As compared with hemato-porphyrin, the only approved photosensitizer, hypocrellins have several advantages, such as easy preparation and easy purification, high triplet quantum yield, high singlet-oxygen quantum yield, high phototoxicity but low dark toxicity, and rapid clearance from normal issues. This article reviews briefly the photophysics, photochemistry and photobiology of hypocrellins on the basis of the domestic and international research results.

ESR STUDIES ON THE SEMIQUINONE RADICAL ANIONS OF HYPOCRELLIN B AND ITS DERIVATIVES AND THE PRODUCTION OF ^(1)O_(2),O_(2)^(█*)

Ⅰ. INTRODUCTIONHypocrellins are 3, 10-dihydroxyl-4, 9-perylenequinone derivatives. They are potent inhibitors of cancer cells. Besides 1O2 and O2, other radicals could also be involved in the effects of Hypocrellins on the photosensitization of erythrocyte membranes. The ESR signal with hyperfine structures could be obtained after illumination of Hypocrellin A, B (HA,