B1 Derivatives Research Articles

Polyphenols and Phenolic Glucosides in Antibacterial Twig Extracts of Naturally Occurring Salix myrsinifolia (Salisb.), S. phylicifolia (L.) and S. starkeana (Willd.) and the Cultivated Hybrid S. x pendulina (Wender.).

(1) Background: Salix species occurring in Finland have not been well studied for their antimicrobial potential, despite their frequent use for lung and stomach problems in traditional medicine. Thus, twig extracts of three species of Salix that are found naturally in Finland and one cultivated species were screened for their antimicrobial properties against human pathogenic bacteria. S. starkeana and S. x pendulina were screened for antibacterial effects for the first time. (2) Methods: An agar diffusion and a microplate method were used for the screenings. Time-kill effects were measured using a plate-count and a microplate method. A DPPH-method using a qualitative TLC-analysis was used to detect antioxidant compounds in antimicrobial extracts. Metabolites from a S. myrsinifolia extract showing good antibacterial effects were identified using UPLC/QTOF-MS. (3) Results: A methanol extract of S. starkeana was particularly active against B. cereus (MIC 625 µg/mL), and a methanol extract of S. myrsinifolia showed good activity against S. aureus and B. cereus (MIC 1250 µg/mL) and showed bactericidal effects during a 24 h incubation of B. cereus. Moreover, a decoction of S. myrsinifolia resulted in good growth inhibition against P. aeruginosa. Our UPLC/QTOF-MS results indicated that proanthocyanidins (PAs), and especially the dimer procyanidin B1 (m/z 577) and other procyanidin derivatives, including highly polymerized proanthocyanidins, were abundant in S. myrsinifolia methanol extracts. Procyanidin B1 and its monomer catechin, as well as taxifolin and p-hydroxycinnamic acid, all present in S. myrsinifolia twigs, effectively inhibited B. cereus (MIC 250 µg/mL). (4) Conclusions: This study indicates that Finnish Salix species contain an abundance of antibacterial condensed tannins, phenolic acids and other polyphenols that deserve further research for the antibacterial mechanisms of action.

Abstract 7311: Lipid soluble vitamin B1 derivatives, benfotiamine and fursultiamine, prevent breast cancer cells growth

Abstract Breast cancer is the leading cause of cancer death in women in the US and the second leading cancer after skin cancer in women worldwide. According to the CDC, women from 45-84 years of age are most at risk, with approximately 30% of deaths in this group being from cancer. Increased free radical formation, and oxidative and inflammatory responses have been shown to be major contributing factors for the progression of breast cancer. Several antioxidants and vitamins have been tested for their efficacy in preventing breast cancer. However, the role of vitamin B1 derivatives in the prevention of breast cancer is not known. Therefore, we hypothesize that with potent anti-oxidative and anti-inflammatory actions, lipid-soluble derivatives of vitamin B1 (thiamine), such as benfotiamine and fursultiamine, could prevent breast cancer growth and spread. We have treated human breast cancer cells such as MCF-7 and T-4D1 and mouse breast cancer cells 4T1 with vitamin B1 derivatives and examined the cancer cells growth. Our results indicate that treatment of various breast cancer cells with benfotiamine and fursultiamine prevents the proliferation of cancer cells in a dose-dependent manner. Further, both benfotiamine and fursultiamine by regulating the activation of caspase-3 and cleavage of PARP protein could prevent breast cancer cells growth. Benfotiamine and fursultiamine also regulates generation of reactive oxygen species in breast cancer cells. Further, vitamin B1 derivatives regulate the expression of various anti-apoptotic, pro-apoptotic, survival and inflammatory factors in both human and mouse breast cancer cells. We next planned to examine the effect of vitamin B1 derivatives on breast cancer growth in vivo using athymic nude mouse models. In conclusion, our in vitro results suggest that vitamin B1 derivatives, benfotiamine and fursultiamine, by promoting the apoptotic pathways prevent breast cancer cells growth and could be further developed as chemopreventive drugs. Citation Format: Caroline Ciaciuch O'Neill, Aveline P. Langmead, Kota V. Ramana. Lipid soluble vitamin B1 derivatives, benfotiamine and fursultiamine, prevent breast cancer cells growth [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7311.

Design of a three-loop asymmetric coil producing a homogeneous radiofrequency B1 field gradient along the axis of a vertical sample tube

A coil system generating a vertical radio-frequency (rf) field gradient (B1 gradient) has been built for surrounding, in a horizontal magnet, a vertical sample (object) of axial symmetry. The system comprises three coaxial loops with an overall shape either spherical or ellipsoidal. The geometry has been theoretically and experimentally devised for producing a very uniform gradient (cancellation of B1 derivatives from second order up to sixth order) in the central region where a vertical receiver/transmitter coil is installed. The latter is of the saddle-shaped type and is geometrically and electrically decoupled from the gradient coil system. This receiver/transmitter coil not only ensures an optimal signal reception but, in addition, is able to deliver perfectly homogeneous rf hard pulses which are mandatory in most NMR experiments. In its present design, the system delivers a uniform gradient in a limited region but could be extended at will. Its main advantages over static field gradients (B0 gradients) appear clearly in the case of very short transverse relaxation times. This property has been emphasized in the case of experiments leading to the measurement of diffusion coefficients. Also, this system would be suitable for chemical shift imaging (CSI) experiments as confirmed by a preliminary test experiment.

Preparation of 3-O-, 5-O- and N-palmitoyl derivatives of fumonisin B1 toxin and their characterisation with NMR and LC-HRMS methods

We have previously published six esterified O-acyl (EFB1) and three N-acyl fumonisin B1 derivatives extracted from rice cultures inoculated with Fusarium verticillioides, amongst these the identification of N-palmitoyl-FB1 has been clearly established in a spiking experiment. At that time, it was assumed that as in the case of O-acyl-FB1 derivatives, linoleic-, oleic- or palmitic acid esterify through the OH group on the 3C or 5C atom of the carbon chain of the fumonisins. In our most recent experiments, we have synthetically acylated the FB1 toxin and subsequently purified 3-O-palmitoyl- and 5-O-palmitoyl-FB1 toxins in addition to the N-palmitoyl-FB1 toxin. They were identified and characterised using 1H and 13C NMR as well as LC-HRMS. Our aim was the identification of the previously detected O-acyl-FB1 derivatives over the course of a spiking experiment, which were obtained through the solid-phase fermentation of Fusarium verticillioides. By spiking the three synthesized and identified components one-by-one into the fungal culture extract and analysing these cultures using LC-MS, it was clearly demonstrated that the F. verticillioides strain produced both the 5-O-palmitoyl-FB1 and N-palmitoyl-FB1 toxins, but did not produce 3-O-palmitoyl-FB1. Thus, it is highly probable that the components thought to be 3-O-acyl-(linoleoyl-, oleoyl-, palmitoyl-) FB1 derivatives in our previous communication are presumably 10-O-acyl-FB1 derivatives. Since these acylated FB1 derivatives can occur naturally in e.g. maize, the use of these synthesized components as reference materials is of great importance in order to obtain accurate qualitative and quantitative data on the occurrence of acylated fumonisins in different matrices including maize based feed samples. The production of these substances has also made it possible to test their toxicity in cell culture and small animal experiments.

Комплексообразование производных полимиксина В1 с гепарином

Комплексообразование производных полимиксина В1 с гепарином

Multivariate statistical analysis of the polyphenolic constituents in kiwifruit juices to trace fruit varieties and geographical origins

Fifty-one kiwifruit juice samples of seven kiwifruit varieties from five regions in China were analyzed to determine their polyphenols contents and to trace fruit varieties and geographical origins by multivariate statistical analysis. Twenty-one polyphenols belonging to four compound classes were determined by ultra-high-performance liquid chromatography coupled with ultra-high-resolution TOF mass spectrometry. (−)-Epicatechin, (+)-catechin, procyanidin B1 and caffeic acid derivatives were the predominant phenolic compounds in the juices. Principal component analysis (PCA) allowed a clear separation of the juices according to kiwifruit varieties. Stepwise linear discriminant analysis (SLDA) yielded satisfactory categorization of samples, provided 100% success rate according to kiwifruit varieties and 92.2% success rate according to geographical origins. The result showed that polyphenolic profiles of kiwifruit juices contain enough information to trace fruit varieties and geographical origins.

Synthesis of Dipeptide and Carbohydrate Ivermectin B1 Derivatives

Synthesis of Dipeptide and Carbohydrate Ivermectin B1 Derivatives

Investigation of Naturally Occurring Fumonisin B1 and Glycated Fumonisin B1 in Korean Feedstuffs

Mycotoxins are potentially dangerous contaminants of livestock feeds. In this study, we measured the levels of fumonisin B1 and glycated fumonisin B1 in feedstuffs and then investigated the ability of the extrusion heating regimen to convert the most prevalent mycotoxin contaminant, fumonisin B1, to a less toxic glycated form. All feed samples were analyzed with fully validated methods. All measured concentrations of fumonisin B1 were below harmful thresholds, including European Union-recommended levels or US Food and Drug Administration action levels. Because fumonisin B1 was highly contaminated mycotoxin in our present investigation and fumonisin B1 has been shown to be less toxic following Maillard type reaction with reducing sugar, we examined the formation of fumonisin B1 derivatives by Maillard reaction under extrusion process conditions. We employed a variety of tandem mass spectrometric methodologies to selectively detect fumonisin B1 derivatives and to elucidate their structures partially. We found that compounds of m/z 736 were more likely artifacts or side reaction products rather than glycation products. N-(carboxymethyl) fumonisin B1 of m/z 780 and other major glycation products of m/z 794 and 810 were not detected, and only negligible amounts of methylene fumonisin B1 was found in 10 extruded feed samples. Therefore, either the tested extrusion conditions did not induce fumonisin B1 glycation or the glycation products simply could not be detected by the method employed in this study.

In vivo formation of N-acyl-fumonisin B1.

Fumonisins are fungal toxins found in corn and in corn-based foods. Fumonisin B1 (FB1) is the most common and is toxic to animals, causes cancer in rodents, and is a suspected risk factor for cancer and birth defects in humans. The hydrolyzed form of FB1 (HFB1) also occurs in foods and is metabolized by rats to compounds collectively known as N-acyl-HFB1 (also known as N-acyl-AP1). N-acyl-HFB1 is structurally similar to ceramides, metabolites which have important structural and signaling functions in cells. FB1 is N-acylated in vitro to ceramide-like metabolites which, like FB1, are cytotoxic. However, metabolism of FB1 and inhibition of ceramide synthase by its metabolites in vivo has not been demonstrated. Male rats were dosed ip with 0.5, 1, or 2 mg/kg body weight FB1 on five consecutive days and the liver and kidney thereafter processed for chemical analysis. N-acyl derivatives of fumonisin B1 were identified for the first time in these principal target organs of FB1 in rats, at levels up to 0.4 nmol/g tissue using mass spectrometry. The N-acyl chain length of the metabolites varied in a tissue-dependent manner with C16 derivatives predominating in the kidney and C24 derivatives being prevalent in the liver. The toxicological significance of N-acyl-fumonisins is not known and warrants investigation.Electronic supplementary materialThe online version of this article (doi:10.1007/s12550-014-0211-5) contains supplementary material, which is available to authorized users.

Synthesis and evaluation of anticonvulsant activities of some bis Mannich bases and corresponding piperidinols.

Some acetophenone derived bis Mannich bases (B1-B5) and piperidinols (C1, C4), which are the structural isomers of B1 and B4, and also quaternary piperidine derivative C6 were synthesized and studied for anticonvulsant activity. Of the compounds, C6 was reported for the first time. Chemical structures of the compounds were confirmed by UV, IR, 1H-NMR, 13C-NMR, mass spectra and elemental analysis. Their anticonvulsant activities were determined by maximal electroshock (MES), subcutaneous metrazol (scMet) tests and rotarod test for neurological deficits. According to the activity studies, B2, B4, C1 and C4 derivatives were found to be protective against MES at 30 mg/kg and above. B1, B2, B3, B4, C4 and C6 derivatives were found to be protective against scMet. at different dose levels ranging from 30 to 300 mg/kg. Since no neurotoxicity was detected for the compounds B4 and C4, they seem to be candidate compounds for further synthesis and in vivo studies for their potential anticonvulsant activity.

Development and validation of a reversed-phase high-performance liquid chromatography assay for polymyxin B in human plasma

The purpose of this study was to develop a specific, sensitive, accurate and reproducible high-performance liquid chromatographic (HPLC) method to measure polymyxin B in human plasma. Derivatization of polymyxin B with fluorescent 9-fluorenylmethyl chloroformate (FMOC-Cl) was performed in the same solid-phase extraction C18 cartridge used for the sample pre-treatment. Reversed-phase HPLC was employed with fluorometric detection. The summed peak areas of polymyxin B1 and B2 derivatives were used for quantification. Stability of polymyxin B FMOC derivatives was examined at room temperature for 6 days. Specificity was investigated against seven potentially co-administered antibiotics. Accuracy and reproducibility of the HPLC assay were determined by inter- and intra-day validation. The derivatives of polymyxin B2 and B1 were well resolved and had retention times of 4.75 and 5.55 min, respectively. Good linearity (r(2) > 0.99) was obtained between 0.125 and 4.00 mg/L polymyxin B in human plasma with good accuracy and reproducibility at the limit of quantification (0.125 mg/L). Intra- and inter-day validation demonstrated good accuracy and reproducibility for quality control samples with nominal concentrations of 0.30 and 3.00 mg/L. FMOC derivatives of polymyxin B were stable for at least 3 days at room temperature. None of the possibly co-administered antibiotics tested interfered with the chromatographic analysis of the polymyxin B FMOC derivatives. A rapid, specific, sensitive, accurate and reproducible HPLC method has been developed and validated to measure polymyxin B in human plasma. The method is suitable for clinical pharmacokinetic studies.

A Novel Plant Protein-disulfide Isomerase Involved in the Oxidative Folding of Cystine Knot Defense Proteins

We have isolated a protein-disulfide isomerase (PDI) from Oldenlandia affinis (OaPDI), a coffee family (Rubiaceae) plant that accumulates knotted circular proteins called cyclotides. The novel plant PDI appears to be involved in the biosynthesis of cyclotides, since it co-expresses and interacts with the cyclotide precursor protein Oak1. OaPDI exhibits similar isomerase activity but greater chaperone activity than human PDI. Since domain c of OaPDI is predicted to have a neutral pI, we conclude that this domain does not have to be acidic in nature for PDI to be a functional chaperone. Its redox potential of -157 +/- 4 mV supports a role as a functional oxidoreductase in the plant. The mechanism of enzyme-assisted folding of plant cyclotides was investigated by comparing the folding of kalata B1 derivatives in the presence and absence of OaPDI. OaPDI dramatically enhanced the correct oxidative folding of kalata B1 at physiological pH. A detailed investigation of folding intermediates suggested that disulfide isomerization is an important role of the new plant PDI and is an essential step in the production of insecticidal cyclotides. The nucleotide sequence(s) reported in this paper have been submitted to the GenBank/EBI Data Bank with accession number(s) 911777.

Constitutive activation of the shh–ptc1 pathway by a patched1 mutation identified in BCC

Mutations in the transmembrane receptor patched1 (ptc1) are responsible for the majority of basal cell carcinoma (BCC) cases. Many of these mutations, including ptc1-Q688X, result in premature truncation of the ptc1 protein. ptc1-Q688X has been identified in patients with both BCC and nevoid basal cell carcinoma syndrome, an inheritable disorder causing a predisposition to cancer susceptibility. Here we describe a mechanism by which ptc1-Q688X causes constitutive cellular signaling. Cells expressing ptc1-Q688X demonstrate an increase in cell cycle progression and induce cell transformation. The ptc1-Q688X mutant enhances Gli1 activity, a downstream reporter of sonic hedgehog (shh)-ptc1 signaling, independent of shh stimulation. In contrast to wild-type ptc1, ptc1-Q688X fails to associate with endogenous cyclin B1. Expression of nuclear-targeted cyclin B1 derivatives promotes Gli1-dependent transcription, which correlates temporally with cyclin B1-cdk1 kinase activity. Coexpression of wild-type ptc1 with a nuclear-targeted cyclin B1 derivative, mutated to mimic constitutive phosphorylation, dramatically decreases Gli1 activity. In addition, the coexpression of this constitutively nuclear cyclin B1 derivative with ptc1-Q688X substantially enhances foci formation. These studies therefore describe a molecular mechanism for the aberrant activity of ptc1-Q688X that includes the premature activation of the transcription factor Gli1.

Synthesis and insecticidal activity of 5-acyloxyimino-5-deoxyavermectin B1 derivatives.

Four novel 5-acyloxyimino-5-deoxyavermectin B1 compounds have been synthesized from avermectin B1 by selective oxidization of the hydroxy group at C-5, followed by oximation and convenient esterification. Their structures were confirmed by IR, 1H NMR, 13C NMR and MS. Insecticidal activities of the intermediate oxime and the four new acyl derivatives were evaluated against Helicoverpa armigera, Spodoptera exigua and Musca domestica.

Synthesis and Evaluation of Anticonvulsant Activities of Some Bis Mannich Bases and Corresponding Piperidinols.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Comparative Characterization of Immune Reagents Based on Hemiacetals of Aflatoxin B 1 and Sterigmatocystine

Aflatoxin B1 and sterigmatocystine hemiacetal derivatives were synthesized, and their conjugation to albumins and gelatin and also spectral and immunochemical characteristics of reaction products were studied. Data on the specificity and analytical properties of the antibodies produced by immunization with conjugated antigens are given. The possible mechanism of hemiacetal interaction with proteins is discussed. Based on immune reagents to sterigmatocystine hemiacetal, a test system was developed for determination of sterigmatocystine at the sensitivity of 0.1 ng/ml.

Patched1 interacts with cyclin B1 to regulate cell cycle progression.

The initiation of mitosis requires the activation of M-phase promoting factor (MPF). MPF activation and its subcellular localization are dependent on the phosphorylation state of its components, cdc2 and cyclin B1. In a two-hybrid screen using a bait protein to mimic phosphorylated cyclin B1, we identified a novel interaction between cyclin B1 and patched1 (ptc1), a tumor suppressor associated with basal cell carcinoma (BCC). Ptc1 interacted specifically with constitutively phosphorylated cyclin B1 derivatives and was able to alter their normal subcellular localization. Furthermore, addition of the ptc1 ligand, sonic hedgehog (shh), disrupts this interaction and allows cyclin B1 to localize to the nucleus. Expression of ptc1 in 293T cells was inhibitory to cell proliferation; this inhibition could be relieved by coexpression of a cyclin B1 derivative that constitutively localizes to the nucleus and that could not interact with ptc1 due to phosphorylation-site mutations to ALA: In addition, we demonstrate that endogenous ptc1 and endogenous cyclin B1 interact in vivo. The findings reported here demonstrate that ptc1 participates in determining the subcellular localization of cyclin B1 and suggest a link between the tumor suppressor activity of ptc1 and the regulation of cell division. Thus, we propose that ptc1 participates in a G(2)/M checkpoint by regulating the localization of MPF.

Of sick turkeys, kwashiorkor, malaria, perinatal mortality, heroin addicts and food poisoning: research on the influence of aflatoxins on child health in the tropics.

Similarities between the geographical and climatic prevalences of kwashiorkor and of exposure to dietary aflatoxins, and between the biochemical, metabolic and immunological derangements in kwashiorkor and those in animals exposed to aflatoxins, prompted investigation of the associations between kwashiorkor and aflatoxins. Studies in Africa in the 1980s indicated a role for these toxins in the pathogenesis of the disease. Paediatric cases of kwashiorkor are less prone to severe Plasmodium falciparum malaria than normal children. In mice infected with P. berghei, aflatoxin exposure inhibits parasite growth and ameliorates morbidity. Aflatoxins occur in < or = 40% of samples of breast milk from tropical Africa, usually as low concentrations of the relatively non-toxic derivatives of aflatoxin B1 (AFB1) but sometimes as high concentrations of the very toxic AFB1. This could explain kwashiorkor in breast-fed babies. Aflatoxin exposure occurs in > or = 30% of pregnancies in tropical Africa and the toxins are often in cord blood, sometimes at extremely high concentrations. Aflatoxins are now incriminated in neonatal jaundice and there is circumstantial evidence that they cause perinatal death and reduced birthweight. Aflatoxin-induced immunosuppresion may explain the aggressive behaviour of HIV infection in Africa. There are similarities between observations on HIV cases in Africa and those on heroin addicts in Europe, where 'street' heroin is frequently contaminated with aflatoxin. Aflatoxins were found in 20% of random urine samples from heroin addicts in the U.K. and the Netherlands. Aflatoxins have also been incriminated in episodes of food poisoning which have been associated with serious morbidity and mortality, particularly among young children.

In Vitro Kinetic Studies of Formation of Antigenic Advanced Glycation End Products (AGEs): NOVEL INHIBITION OF POST-AMADORI GLYCATION PATHWAYS

Nonenzymatic protein glycation (Maillard reaction) leads to heterogeneous, toxic, and antigenic advanced glycation end products ("AGEs") and reactive precursors that have been implicated in the pathogenesis of diabetes, Alzheimer's disease, and normal aging. In vitro inhibition studies of AGE formation in the presence of high sugar concentrations are difficult to interpret, since AGE-forming intermediates may oxidatively arise from free sugar or from Schiff base condensation products with protein amino groups, rather than from just their classical Amadori rearrangement products. We recently succeeded in isolating an Amadori intermediate in the reaction of ribonuclease A (RNase) with ribose (Khalifah, R. G., Todd, P., Booth, A. A., Yang, S. X., Mott, J. D., and Hudson, B. G. (1996) Biochemistry 35, 4645-4654) for rapid studies of post-Amadori AGE formation in absence of free sugar or reversibly formed Schiff base precursors to Amadori products. This provides a new strategy for a better understanding of the mechanism of AGE inhibition by established inhibitors, such as aminoguanidine, and for searching for novel inhibitors specifically acting on post-Amadori pathways of AGE formation. Aminoguanidine shows little inhibition of post-Amadori AGE formation in RNase and bovine serum albumin, in contrast to its apparently effective inhibition of initial (although not late) stages of glycation in the presence of high concentrations of sugar. Of several derivatives of vitamins B1 and B6 recently studied for possible AGE inhibition in the presence of glucose (Booth, A. A., Khalifah, R. G., and Hudson, B. G. (1996) Biochem. Biophys. Res. Commun. 220, 113-119), pyridoxamine and, to a lesser extent, thiamine pyrophosphate proved to be novel and effective post-Amadori inhibitors that decrease the final levels of AGEs formed. Our mechanism-based approach to the study of AGE inhibition appears promising for the design and discovery of novel post-Amadori AGE inhibitors of therapeutic potential that may complement others, such as aminoguanidine, known to either prevent initial sugar attachment or to scavenge highly reactive dicarbonyl intermediates.

On the product property of the pluricomplex Green function

We prove that the pluricomplex Green function has the product property 9D1 x D2 = max{g9D1 9D2 } for any domains D1 C C? and D2 C Cm. Let E denote the unit disc in C. For any domain G C C' define 9D(a,z) inf D{ 7 JAIord\(t -a)}, a,zCD, pEO(E, D) A1 (a) ~o(O)=z A~1a aGEo(E) where (?(E, D) denotes the set of all holomorphic mappings E -> D and ordA ((p a) denotes multiplicity of (o a at A. The function 9D is proposed by Poletsky (cf. [Pol]) and is called the pluricomplex Green function for D. We have that (see [Jar-Pfll], Chapter IV) (a) gD (a, z)z inf { J7J AIordx\(~p a)} a,zcD. a C ( E, D) A E ,(a) aGE9(E) Note that in the formula (a) we take only A c (p1 (a) such that A c E. (b) For any domains D1, D2 and any holomorphic mapping f: D1 D2 we have the following contractible property: 9D2 (f (z), f (w)) follows from the property (b). So, we have to prove NlKJv and J6j ... ( > NjIl>K . For, if I(, ... Qvl A), and it contradicts the minimality of v. If (v ?. < 161 .. (Lj, then we replace (P1 with the mapping ;1(A) = (p1(tA), where t : Then |j <1] 1). .. v (use (2)), and (t .. (t)=l-.(. Hence, we may assume that I(,.. (vlI = |(l ...(p C < N. Moreover, replacing (Pj (A) with Pi (e-61 A) and 02(2) with (P2 (e-i2 A), where 01, 02 are chosen such that e i2 8I ... e281 ?_ C and e iO2 ... eiO2 = C, we may assume that (I... (v= 1.H= C. We consider Blaschke products B1(A) = < j=1 J and B1(Av) = _ B1(A)O-B1(O) A A-wa A cE. I Note that mappings P1j and 02 are holorriorphic in some neighborhood of E, and the sets ypj 1(al) and o1 may contain points outside of E. 2For example, it is enough to change very little the mappings y01 and p2 by the formula (3) given below. This content downloaded from 157.55.39.170 on Tue, 26 Jul 2016 06:23:20 UTC All use subject to http://about.jstor.org/terms TI'HE PRODUCTI' PROPERTI'Y OF TI'HE PLURICOMvPLEX GREEN FUNCTI'ION 2857 We choose different wj, 1 < j < v, as close to wj as we want such that O C {w1,. .. ,w'}. Define Aw' Note that B7i1(-C) {?i,...,Q} We can find w',...,w' such that G71(-C) consists of v different points I, 1 ? j < V, as close to points ?j as we want. Let us replace the mapping pi with the mapping (3) (j) := (p(A)-a, ) += Clearly, when j, 1 < j < V, are sufficiently close to (j, ;i maps E into D1 (recall that ,oj maps some neighborhood of E into D1, hence 9p1(E) @ DI), and (71 (?) = (01 (?), I4 (?j K) = (01 (?j) Repeating this process for P2, we may assume that for Blaschke products B1 and B2 derivatives are not equal to 0 either on preimages of C or at points ?j or j respectively. Let A be the union of images of singular points under mappings B1 and B2. Note that neither 0 nor C is in A. Let ir be a holomorphic universal covering of E A by E with ir(0) = C. There are liftings Vl' and V)2 mapping E into E such that 7r = B, o 01 = B2 f({2 andj1(?) = 02(0) = O. If7r-1(0) = {711,j2,.... .}, then mappings (Pj o? 1 and (P2 o 02 map 0 into a2 and b2, and all points 71 into a, and b1 respectively. Note that ir has all radial limits either in aE or in A. Since A is finite, Xr is an inner function. By Theorem 2 of Ch. III in [Nos], every inner function which has no zero radial limits is a Blaschke product. Thus