Isoflavonoid glycosides from Dalbergia sissoo

Two isoflavone glycosides, biochanin A 7-O-[beta-D-apiofuranosyl-(1-->5)-beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside] and tectorigenin 7-O-[beta-D-apiofuranosyl-(1-->6)-beta-D-glucopyranoside], were isolated from Dalbergia sissoo. Their structures were elucidated on the basis of spectral and chemical evidence.

Virol A, a toxic trans-polyacetylenic alcohol of Cicuta virosa, selectively inhibits the GABA-induced Cl(-) current in acutely dissociated rat hippocampal CA1 neurons

The effects of virol A (VA), a toxic component of Cicuta virosa (water hemlock), on the GABA-induced Cl(-) current (I(GABA)) in acutely dissociated rat hippocampal CA1 neurons were investigated using whole-cell patch-clamp techniques. VA reversibly reduced I(GABA) and the muscimol (Mus)-induced current (I(Mus)) in a concentration-dependent manner. The IC(50) values for VA against I(GABA) and I(Mus) were 9.6x10(-7) and 9.8x10(-7) M, respectively. VA shifted the EC(50) value of I(GABA) from 6.5x10(-6) to 2.1x10(-5) M, whereas it had no effect on the maximum response, thereby suggesting that VA inhibited I(GABA) in a competitive manner. VA had no apparent effect on current-voltage relationships for I(GABA), thus indicating the lack of voltage-dependency. On the other hand, application of VA (10(-6) M) did not additionally reduce the I(GABA) suppressed by >10(-5) M picrotoxin. VA but not bicuculline accelerated the decay phase of I(GABA), as was seen with picrotoxin. Moreover, pre-application of 10(-5) M VA reduced I(GABA). VA did not inhibit that induced by glycine (10(-4) M). These results indicate that VA inhibits I(GABA) by acting both on the GABA agonist site and on the Cl(-) channel of the GABA(A) receptor-channel complex. VA is a structurally novel type of compound that selectively inhibits the GABA(A) receptor-Cl(-) channel complexes in mammalian central nervous system neurons.

Exploring the structural basis of neurotoxicity in C(17)-polyacetylenes isolated from water hemlock

Water hemlock, Cicuta virosa, belonging to the Umbelliferae, is well-known as a toxic plant responsible for lethal poisonings in humans as well as animals, causing tonic and clonic convulsions and respiratory paralysis. Cicutoxin (1), being a major violent toxin of the plant, is a chemical in the class of C(17)-polyacetylenes bearing a long pi-bond conjugation system, a terminal hydroxyl, and an allylic hydroxyl in its structure, and a variety of its analogues have been isolated from the plant. In the present study, various derivatives of these toxins were synthesized through acetylation, methylation, and oxidation of cicutoxin (1) and virol A (3) and B (4). 1-Dehydroxyvirol A (28) was prepared through the coupling of (7S)-dodeca-3,5-dien-1-yn-7-ol and 1-iodopentyne under Sonogashira's conditions. A monoacetylenic compound (29) was also prepared through the coupling of (5S)-1-chlorodeca-1,3-dien-5-ol and 1-iodopentyn-5-ol. The structure-activity relationships involved in the acute toxicity of cicutoxin derivatives in mice were investigated, and the length and geometry of pi-bond conjugation and the O-functional groups were found to be important for activity. The potency in inhibition of the specific binding of the noncompetitive GABA antagonist, [(3)H]EBOB, to GABA-gated Cl(-) channels of GABA receptors in rat brain cortex was found to be correlated with acute toxicity, indicating that the ability to bind to these channels plays an important role in the acute toxicity of these compounds.

In vivo subcellular elemental dynamics in liver graft: With special reference to effect of non-selective endothelin receptor antagonist, TAK-044, on the graft injury

Background: No data are available concerning the in vivo subcellular dynamics of elements in liver grafts and the effect of endothelin receptor antagonist, TAK-044, against graft injury. Methods: Liver transplantation was performed in porcine under active veno-venous bypass. The grafts stored in chilled preservation solution were recirculated following reflush with lactated Ringer's solution with or without TAK-044 (10 mg/kg). Cold and warm ischemic times of the grafts were comparable between the two groups. Elements (Na, K, Cl, Ca, P and S) were measured in three fractions of cytoplasm, mitochondria and nucleus by electron probe X-ray microanalysis for the graft biopsy specimens obtained at various time from donor laparotomy to 1 week after liver grafting. Liver functions also were compared between the two groups. Results: In both groups, concentration of each element changed in parallel among the three subcellular fractions and their changes were less marked in the nucleus. In the control group, there were significant increases in cytoplasmic Na and Cl after portal reperfusion and in cytoplasmic and mitochondrial Ca after hepatic artery reperfusion. These were accompanied by K and mitochondrial S decreases without a statistical significance. In the TAK group, such postreperfusion elemental alterations were significantly suppressed and early deterioration of the liver functions was alleviated, as compared with the control group. Conclusion: A supplemental use of TAK-044 in a rinse solution before reflush contributed to stability of subcellular elements after reperfusion and better preservation of early graft function.

[A case of Marchiafava-Bignami disease that responded to high-dose intravenous corticosteroid administration]

We report a 63-year-old male who presented acute confusional state with prominent rigidity of all extremities. The patient had a long history of alcoholism and was in poor physical condition and malnourished. The diagnosis of Marchiafava-Bignami disease was indicated by T2-weighted MRI demonstrating high signal intensity in the corpus callosum. Because Wernicke's encephalopathy was suspected as a complication, thiamine therapy was applied, but there was no clinical improvement. Immediately after high-dose intravenous corticosteroid administration was started, his symptoms rapidly resolved except for mild cognitive impairment. It is supposed that edematous change in the early stages of Marchiafava-Bignami disease causes impairment of the blood-brain barrier. Steroid therapy may prevent such a process by means of its the anti-edema effect and by normalizing blood-brain barrier. The present case suggests that corticosteroid therapy has beneficial effects for Marchiafava-Bignami disease.

[Biological activities of natural resources around us are now in the limelight]

There are various kind of natural resources around us, and they must contain a lot of unknown bioactive substances. Some may be structurally very strange for us, and some are very familiar. But their biological activity was not unfortunately investigated in detail. Accordingly, exploring new types of pharmaceutical resources may give lead compounds of the drugs in the future. Among those natural resources, I examined squid ink and scallop soup. From squid ink, an antitumor glycoconjugate was obtained. Its polysaccharide moieties, illexin A, illexin B and illexin C, were isolated, and the spectral data and chemical transformation of their acid hydrolysate revealed to bear a unique branched repeating unit, [-3GlcA beta 1-4(GalNAc alpha 1-3)Fuc alpha 1-]n. Moreover, scallop soup gave antitumor glycogen by the action of protease. The fine structure of glycogen was investigated by the sequential enzyme digestion method using beta-amylase and pullulanase, while the unit chain was analyzed by high performance anion exchange chromatography. The results showed that the antitumor active glycogen was highly branched with shorter chain than glycogens without antitumor activity.

Asymmetric 1,4-addition of phenylboronic acid to 2-cyclohexenone catalyzed by Rh(I)/binap complexes

Reaction of 2-cyclohexenone with phenylboronic acid in the presence of 3 mol% of a rhodium(I)/(S)-binap catalyst in dioxane/H2O (10/1) at 100 degrees C proceeded with high enantioselectivity to give a high yield of (S)-3-phenylcyclohexanone of up to 99% ee. The high enantioselectivity was achieved by use of a catalyst generated in situ from Rh(acac)(C2H4)2 and (S)-binap or Rh(acac)((S)-binap) as an isolated rhodium-phosphine complex.

Novel acyl alpha-pyronoids, dictyopyrone A, B, and C, from Dictyostelium cellular slime molds

For the elucidation of the diversity of secondary metabolites of Dictyostelium cellular slime molds, we investigate the constituent of three species of slime molds. From the methanol extract of their fruit bodies, we obtained three novel compounds, dictyopyrone A (1) and B (2) from D. discoideum and D. rhizoposium and dictyopyrone C (3) from D. longosporum. They possess a unique alpha-pyrone moiety with a side chain at the C-3 position. Their relative structures were elucidated by spectral means, and the absolute configuration was confirmed by asymmetric synthesis of 1. Since these compounds were obtained from different species of Dictyostelium slime molds, they may be a type of compound common to this genus.

New type of febrifugine analogues, bearing a quinolizidine moiety, show potent antimalarial activity against Plasmodium malaria parasite

Febrifugine (1) and isofebrifugine (2), isolated from the roots of Dichroa febrifuga Lour. (Chinese name: Cháng Shan), are active principles against malaria. Adducts of 1 and 2 with acetone, Df-1 (3) and Df-2 (4), respectively, were obtained using silica gel and acetone. They showed high activity against P. falciparum malaria in vitro. Compound 3 was found to be equally effective against P. berghei in vivo as the clinically used drug chloroquine, whereas 4 showed only 1/24 of the activity of 3. Metabolism studies of these compounds revealed that compound 4 is readily metabolized in mouse liver. Accordingly, the dose of 4 must be higher than that of 3 to attain blood levels sufficient for a favorable therapeutic effect.

Stimulation of neurotrophic factor secretion from 1321N1 human astrocytoma cells by novel diterpenoids, scabronines A and G

Glial cells release neurotrophic factors that maintain neurons functionally. When rat pheochromocytoma cells (PC-12) were cultivated with the conditioned medium of human astrocytoma cells (1321N1) incubated with the new diterpenoids, scabronines A and G, isolated from Sarcodon scabrosus, they changed their morphology and there was neurite outgrowth. The scabronines increased the expression of mRNA for nerve growth factor (NGF), and the secretion of NGF from 1321N1 cells in a concentration-dependent manner. However, the enhanced neurite outgrowth produced by the conditioned media was slightly inhibited by NGF neutralizing antibody, and the concentration of NGF released in response to the scabronines was insufficient to cause differentiation. These results suggest that scabronines cause the secretion of other factors together with NGF from 1321N1 cells. The diterpenoids are useful drugs to clarify the mechanism of synthesis and secretion of neurotrophic factors.

Serial MR findings of chronic idiopathic ataxic neuropathy

We report the case of a 70-year-old woman with chronic idiopathic ataxic neuropathy. Neurological examination, electrophysiological studies and a sural nerve biopsy suggested involvement of the axon and the dorsal root ganglia. Laboratory examination showed polyclonal elevation of serum IgA. MRI showed high signal intensity in the posterior column of the lumbar spinal cord on T2-weighted images. High signal intensity in the posterior column of the cervical spinal cord on T2-weighted images appeared during the course of the illness. MR abnormalities in this case may reflect the degeneration of the posterior column of the spinal cord subsequent to sensory ganglionic neuropathy.

Anti-tumor activity of squid ink

The anti-tumor activity of a new type of peptidoglycan isolated from squid ink was shown to have a cure rate of 64% for Meth A tumor from BALB/c mice. The ink delipidated in acetone, which contained the peptidoglycan at 0.1% (w/w), was administered to tumor-transplanted mice so as to examine the anti-tumor activity. One-fifth of the tumor-bearing mice was cured with 3 injections (1 mg/head) of the acetone delipidated squid ink or a prolongation of survival was observed in the treated animals. Heat treatment at 100 degrees C for 10 min did not affect the anti-tumor activity of the delipidated ink, its potentiality being preserved. The acetone-extractable fraction of the ink also brought about a similar cure rate for Meth A tumor. The delipidated ink enhanced the phagocytic activity of macrophages but no direct cytotoxicity was observed for the Meth A tumor cells. Hence it may be said that the anti-tumor activity of the delipidated ink was mainly due to the augmented cellular immunity in vivo.

Hepatoprotective effect of a nonselective endothelin receptor antagonist (TAK-044) in the transplanted liver

This study was designed to investigate whether or not a novel nonselective endothelin A/B (ETA/ETB) receptor antagonist (TAK-044) provides hepatoprotection during porcine liver transplantation. The grafts were stored in chilled Euro-Collins solution and recirculated following reflush with lactated Ringer's with (TAK group) or without (control group) TAK-044 (10 mg/kg). Intracellular (cytoplasma, mitochondria, and nucleus) calcium (Ca) concentrations were measured in the hepatic biopsy materials obtained serially at varying time point from donor laparotomy to recipient closure using an electron probe X-ray microanalyzer. Liver function tests also were determined. The cold and warm ischemia times of the grafts were comparable between the two groups. The peak endothelin-1 T-1) concentration after recirculation was significantly higher in the TAK group than in the control group (129 +/- 30 pg/ml vs 26 +/- 6.5 pg/ml). However, release of liver enzymes, increases in total bile acid, and deterioration of indocyanine green retention rate were significantly suppressed in the TAK group. In the control group, the intracellular Ca concentrations, especially in the mitochondrial fraction, were elevated markedly following recirculation of the hepatic arterial flow. In the TAK group, this effect was suppressed. Thus, the supplementary use of the nonselective ETA/ETB receptor antagonist TAK-044 via a rinse route may alleviate an early postreperfusion microcirculatory disturbance of the liver grafts without adverse effects by the increased ET-1 on the systemic circulation.

[Efficacy of TRH-T for spinocerebellar degeneration--the relation between clinical features and effect of TRH therapy]

Thyrotropin releasing hormone (TRH) therapy has been frequently attempted for the treatment of spinocerebellar degeneration (SCD) and its efficacy has been confirmed. However, effectiveness is considered to differ depending on disease type, severity and the method of evaluating clinical improvement. We investigated the efficacy of thyrotropin releasing hormone-tartrate (TRH-T) in 23 patients with SCD consisting of cerebellar form (cortical cerebellar atrophy (CCA) and hereditary cortical cerebellar atrophy (H-CCA)), and multiple system form (multiple system atrophy (MSA) and hereditary olivopontocerebellar atrophy (H-OPCA)). TRH-T, 2 mg per day, was given intravenously for 20 days. The effect of TRH therapy was evaluated by assessing changes in balance function while lying, sitting, standing and walking, that may reflect the movement functions in active daily life (ADL) for the patients with SCD. The speech function was also evaluated qualitatively using acoustic analysis. The amine metabolites (HVA and 5-HIAA) in cerebrospinal fluid possibly reflecting the noradrenaline and serotonin metabolism in the central nervous system were measured before and after treatment. Although mild or moderate improvement of the balance function during the course of TRH therapy was seen in 16 of the 23 patients, patients with cerebellar forms (CCA and H-CCA) improved significantly as compared to patients with MSA. The effect persisted for a long time (mean; 3.8 months) after TRH therapy in nine of the 16 patients, and eight (88.9%) of the nine had the cerebellar form of SCD. The levels of HVA and 5-HIAA in CSF also increased in patients with CCA as compared to patients with MSA and H-OPCA. The disease severity before the treatment in 14 (87.5%) of 16 patients who showed improvement of balance functions by TRH therapy was mild or moderate; possible of walking without support, or occasionally with support. Considering these results together, TRH therapy may be effective in patients with the cerebellar form of SCD, whose illness severity is mild, and may be recommended for support of ADL in patients with the cerebellar form of SCD.

Serial MRI and SPECT in amyotrophic lateral sclerosis: a case report

We report the case of a 42 year-old woman with amyotrophic lateral sclerosis (ALS). Neurological examination showed spastic paraparesis and muscular atrophy of the upper extremities. Increased signal intensity areas were present in the lateral corticospinal tract of the brain and cervical spinal cord on a T2-weighted image. Decreased signal intensity of the motor cortex on the T2-weighted image appeared during the course of the illness. SPECT showed hypoperfusion confined to the motor cortex. The area of increased signal intensity in the cervical spinal cord on the T2-weighted MR images extended to the anterolateral columns of the spinal cord. The area of hypoperfusion in SPECT extended to the fronto-parietal area with the progression of the disease. These changes in the MRI and SPECT findings may reflect progressive degeneration of the upper motor neurons in ALS.

MRI of adrenoleukodystrophy involving predominantly the cerebellum and brain stem

A case of adult-onset adrenoleukodystrophy involving predominantly the cerebellum and brain stem is described. The patient was a 30-year-old man with no family history of adrenoleukodystrophy. His neurological symptoms were progressive cerebellar ataxia and spastic paraparesis. CT showed atrophy of the cerebellum and brain stem. MRI disclosed lesions, enhancing partially with gadolinium, in the dentate nuclei and the pyramidal tracts from the internal capsule to the brain stem. The biochemical findings were compatible with typical adrenoleukodystrophy, but the distribution of the lesions on MRI was distinctly different. After steroid administration, the patient's symptoms improved slightly and contrast enhancement of the lesions was markedly reduced.

Illexins A, B, and C from squid ink should have a branched structure

Illexin A, illexin B, and illexin C, isolated from ink of the squid Illex argentinus, have been reported to have a structure consisting of linear repeating units of (-6GalNAc alpha 1-3GlcA beta 1-3Fuc alpha 1-)n [Biochem. Biophys. Res. Commun. 198, 560 (1994)]. This structure was further investigated using NOESY and atmospheric pressure MS/MS measurement of PA-trisaccharide obtained by acid hydrolysis of illexin C. The results indicated that the structure is, in fact, branched. Observation of both [GalNAc-Fuc-PA]- and [GlcA-Fuc-PA]+ obtained as product ions from the molecular ion of PA-trisaccharide on the MS/ MS spectra suggested a branched repeating unit. NOEs between H-1 of GalNAc and H-3 of Fuc, and between H-1 of GlcA and H-4 of Fuc, revealed the positions of glycosidic linkages, and from the results of sodium periodate oxidation of illexin C and PA-trisaccharide, the structure was determined to be (-3GlcA beta 1-4(GalNAc alpha 1-3)Fuc alpha 1-)n.

[Dissociated adduction nystagmus in a patient with hereditary spinocerebellar degeneration]

A 66-year-old woman with a 10 years' history of autosomal dominant hereditary spinocerebellar degeneration developed an atypical nystagmus. Neurological examination revealed cerebellar ataxia, absent tendon reflex, supranuclear upward gaze palsy, saccadic pursuit and nystagmus. Nystagmus was a dissociated type and appeared only in lateral gaze and the amplitude was prominent in adducting eyes. Brain MRI showed cerebellar hemispheric and vermal atrophy, and pontine atrophy. Neuro-otological examination revealed normal caloric test, but impaired optokinetic nystagmus and visual suppression test. The dissociated adduction nystagmus of this case may correspond to gaze evoked nystagmus and latent hypofunction of the abducens motor neurons.

[Complex visual hallucinations in the hemianopic field following an ischemic lesion of the occipitotemporal base--confirmation of the lesion by MRI and speculations on the pathophysiology]

We report a patient who presented with complex visual hallucinations in the right hemianopic field following an infarction in the left occipitotemporal base. A 73-year-old right-handed woman developed right homonymous hemianopia. A week after its onset, she noticed a strange man with glasses, or a man wearing a gray hat and a black coat standing in the defective visual field. Such visual images later included a nurse, a large hand extending from the right side to the center, and many pieces of cloth descending from the roof. Most of these objects were unfamiliar to her, but may have been related to previous experiences. Her hallucinations were usually black and white singular and motionless, and sometimes consisted of multiple identical replications of objects. All of the hallucinations vanished when the patient tried looking directly at them. An EEG failed to showed any epileptic discharges. T1-weighted MRI with gadolinium-DTPA performed nine days after the onset revealed a localized high-signal-intensity region suggesting an infarction around the left collateral sulcus that included part of the lingual gyrus and the fusiform gyrus. 123I-IMP SPECT showed hypoperfusion of the left occipitotemporal base. The hallucinations gradually resolved a month after the onset, but the right homonymous hemianopia persisted. The enhanced lesion on T1-weighted images was no longer visible on MRI performed a month after the onset but, remained high-intensity on the T2-weighted images. There have been reports of complex visual hallucinations in hemianopic fields, but there have been only a few reports in which the responsible lesion was discussed on the basis of the CT and MRI findings. The findings in our patient suggest that lesions of the occipitotemporal base are one of the possible causes of this symptom. Taken together with earlier reports, not only pure release phenomena but irritative phenomena in the association visual cortex may be involved in the complex visual hallucinations in the hemianopic field, as Lance and Kölmel suspected.

[HTLV-I associated myelopathy (HAM) with cerebellar atrophy presenting a down-beat nystagmus]

A 67-year-old woman began to have difficulty in walking due to spastic paraparesis, sensory impairment in the lower limbs and instability on standing at the age of 59 years. Eight years later, she developed complete spastic paraplegia and urinary incontinence. On examination, she was found to have down-beat nystagmus and ocular hypermetria. Brain CT scan and MRI revealed cerebellar atrophy, predominantly in the vermis. HTLV-I antibody titer was increased in both serum and cerebrospinal fluid (CSF). She was diagnosed as having HAM and placed on prednisolone, salazosulfapyridine and high-dose vitamin C. Her symptoms including gait disturbance, nystagmus and ocular hypermetria improved but did not completely disappear. In parallel with clinical improvement, the antibody titer to HTLV and the ratio of CD4/CD8 lymphocyte subsets in blood decreased. The above observations suggest that the cerebellar signs and cerebellar atrophy share the same etiology with HAM. The presence of nystagmus and prominent cerebellar signs plus the CT and MRI findings strongly suggest that the lesions in HAM are not limited to the spinal cord but extend to the brainstem and cerebellum.

[A case of toxoplasmic chorioretinitis and meningoencephalitis in an immunocompetent adult]

A 71-year-old man who presented with toxoplasmic chorioretinitis and meningoencephalitis is reported. He had been healthy and immunologically normal. Initially, he complained of blurring of vision without headache, nor fever. Neurological examinations revealed papilledema, nuchal rigidity, and disorientation. Fluorescent angiography of the ocular fundi disclosed hyperfluorescent leaks suggesting chrioretinitis. His EEG had dysrhythmic slow alpha wave with some theta slowing. CSF studies showed pleocytosis up to 80/mm3; the cells were predominantly lymphocytes. The titers of toxoplasma antibody in the serum and CSF were prominently increased. Toxoplasmosis was highly suspected and he was treated with predinsolone, acetylspiramycin, and pyrimethamine. After the treatment, ophthalmologic and neurological symptoms improved, and the laboratory findings including the titers of toxoplasma antibody in the serum and CSF were also improved. Recently, toxoplasmosis associated with neurological complications as an opportunistic infection is a serious problem in the immunocompromised hosts, especially in AIDS, but this infection is rare in immunologically normal adults. Our case and some other reports may suggest a chance of developing toxoplasmic meningoencephalitis even in healthy individuals. We have to think of the possibility of toxoplasmosis in the immunocompetent hosts when they are presenting with chorioretinitis and meningoencephalitis.

[Studies on analysis of gastric mucosal blood flow by electronic endoscopic image. Especially on atrophic gastritis]

The electronic endoscopic image of gastric mucosa was converted by image processing unit SP-1000 (A/D changed) into the one, which was treated with the color conversion method to measure the gastric mucosal hemoglobin index (Hb-index: HI). At the same time, biopsy specimens of gastric mucosa were removed from such 4 different sites as antrum lesser curvature, lower body lesser curvature, lower body anterior wall and upper body posterior wall. On pathohistological examination, the author observed the inflammatory cell infiltration, mucin production, the number and diameter of blood vessels, the degree of atrophic changes in gastric mucosa. HI values were compared with histological findings and with the degree of endoscopic appearance of blood vessel in the lower body lesser curvature. The following results were obtained. HI values were lower in the group with higher inflammatory cell infiltration and less mucin production, while the values were higher in the group with more numerous vessels and larger size ones in diameter. In the group with higher degrees of the pathohistological atrophic change and the endoscopic appearance of blood vessel, HI showed lower values.