Pentalenolactone I and hygromycin A, immunosuppressants produced by Streptomyces filipinensis and Streptomyces hygroscopicus.

Immunosuppressants isolated from Streptomyces filipinensis and S. hygroscopicus were identified with pentalenolactone I and hygromycin A, respectively. The compounds as well as cyclosporin A showed immunosuppressant activity in the mixed lymphocyte reaction, and pentalenolactone I and cyclosporin A suppressed IL-2 production, however, hygromycin A did not. Hygromycin A may have immunosuppressant activity by a different mechanism from pentalenolactone I, cyclosporin A and tacrolimus.

Biosynthesis of fattiviracin FV-8, an antiviral agent.

Streptomyces microflavus strain No. 2445 produces many derivatives of fattiviracin antibiotics. The major product of these derivatives is fattiviracin FV-8, which consists of four glucose and two trihydroxy fatty acid residues. We found that this strain has the ability to convert several sugars in the culture medium to glucose, and the glucose added to the medium is directly incorporated into the FV-8 molecule. Two trihydroxy fatty acid residues in the FV-8 molecule are derived from acetic acid, and production of FV-8 is inhibited by the addition of cerulenin, which is an inhibitor of fatty acid biosynthesis.

Iron accumulation in the substantia nigra of autosomal recessive juvenile parkinsonism (ARJP).

Autosomal recessive juvenile parkinsonism (ARJP) is a distinct clinical and genetic entity characterized by highly selective neuronal death in the substantia nigra (SN) and locus coeruleus neurons without Lewy body formation. The mechanism of neuronal death of ARJP is still unknown. Our study demonstrated that iron staining was more intense in ARJP than in both controls and sporadic Parkinson's disease (PD), and there were differences in the pattern of distribution of iron staining between ARJP and PD. In addition neurites of SN in ARJP showed intense iron staining. Thus, we postulate that oxidative stress may play an important role in the neurodegeneration that occurs in ARJP.

Antiviral activity of fattiviracin FV-8 against human immunodeficiency virus type 1 (HIV-1).

A novel antiviral agent, fattiviracin FV-8, purified from the culture broth of Streptomyces microflavus strain No. 2445, showed potent antiviral activities against human immunodeficiency virus type 1 (HIV-1), herpes simplex virus type 1 (HSV-1), varicella-zoster virus (VZV), and influenza A and B viruses. The action mechanism of fattiviracin FV-8 against HIV-1 was examined. As a result, the agent was thought to act on HIV-1 particles directly without lysis of the particles, and it affords the inhibition of viral entry into the host cells.

Anti-herpes virus activity of fabaceous triterpenoidal saponins').

Anti-herpes simplex virus type 1 (HSV-1) activity of oleanane-type triterpenoidal saponins obtained from some fabaceous plants were examined. Among sophoradiol glycosides, the order of potency was kaikasaponins III>I>>sophoradiol monoglucuronide. It was suggested that the trisaccharide group showed greater action than the disaccharide group. Neither the monoglucuronide of sophoradiol nor that of soyasapogenol B showed activity. Among the trisaccharide group of soyasapogenol B, the order of activity was azukisaponin V>soyasaponin II>astragaloside VIII>>soyasaponin I. Therefore, the saponin having a glucosyl unit in the central sugar moiety seemed to show greater action. In comparison with the activities for a group having the same trisaccharide, the potency of the sapogenol moieties was found to be in the order of soyasapogenol E>sophoradiol>>soyasapogenol B. Hence, the carbonyl group at C-22 would be more effective than the hydroxyl group in anti-HSV-1 activity, while the hydroxyl group at C-24 could reduce the activity.

Anti-herpes virus activity of Solanum steroidal glycosides.

Since some Solanum-genus plants have traditionally been used for anti-cancer and anti-herpes agents from olden times, we examined anti-herpes simplex virus type 1 (HSV-1) activity of typical steroidal glycosides with the frameworks of spirostane (including nuatigenin glycoside), furostane, solasodane, tomatidane and ergostane (including dimer) obtained from Solanum plants. Among these steroidal glycosides, the spirostanol glycosides were most effective. An inclination was observed for the potency of activity to decrease in the order of spirostane, tomatidane, ergostane, solasodane, nuatigenin type, dimer of ergostane and furostane. It was also suggested that the activity depends on the kind of oligosacchride moiety.

Fattiviracin A1, a novel antiherpetic agent produced by Streptomyces microflavus Strain No. 2445. I. Taxonomy, fermentation, isolation, physico-chemical properties and structure elucidation.

A novel antiherpetic agent, fattiviracin A1, was isolated from the culture broth of strain No. 2445 identified as Streptomyces microflavus. It was purified through 1-butanol extraction, column chromatographies on Diaion HP-10 and silica gel and HPLC using a reverse phase column. The structure of fattiviracin A1 was determined by several spectroscopic experiments and chemical degradations. It is a new macrocyclic diester consisting of four D-glucose units and two (C24 and C33) hydroxy fatty acids. It is closely related to cycloviracins B1 and B2, but differs from these known compounds in both the length of its side chain and the sugar moiety.

Fattiviracin A1, a novel antiviral agent produced by Streptomyces microflavus strain No. 2445. II. Biological properties.

Fattiviracin A1, showed potent antiviral activities against herpes simplex virus type 1 (HSV-1), varicella-zoster virus (VZV), influenza A virus and human immunodeficiency virus type 1 (HIV-1). It showed no cytotoxicity against Vero cells. Fattiviracin A1 exhibited no significant antibacterial or antifungal activities. Treatment of HSV-1 with fattiviracin A1 decreased its infectivity to Vero cells. The mechanism of its antiviral activity may be due to inactivation of the viral particles and inhibition of viral entry into host cells.

A new antiherpetic agent, AH-1763 IIa, produced by Streptomyces cyaneus strain no. 1763.

A new antiherpetic agent, AH-1763 IIa, was isolated from the culture broth of strain No. 1763 identified as Streptomyces cyaneus. It was purified through column chromatographies of Diaion HP-10 and silica gel. The structure was determined to be 11-hydroxy-5-methyl-2-(2-hydroxy-1-methylpropyl)-4H-anthraceno [1,2-b]pyran-4,7,12-trione by several spectroscopic experiments, that is a new antibiotic belonging to pluramycin-group.

A new antiherpetic agent produced by Streptomyces sp. strain no. 758.

A new antiherpetic agent, AH-758, was isolated from the culture broth of Streptomyces sp. strain No. 758. The structure was determined by NMR special analyses to be a new antibiotic belonging to bafilomycin group containing (5-oxo-2-pyrrolin-2-yl) methyl fumarate in its C-21.

Iron accumulation in the substantia nigra of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced hemiparkinsonian monkeys.

The mechanism of abnormal iron accumulation in the substantia nigra (SN) pars compacta of patients with Parkinson's disease (PD) is unknown. To explore this question, we made a hemiparkinsonism model in monkeys by injecting 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) into the caudate or putamen on one side, and compared iron content in the SN and other basal ganglia structures by histochemistry. The injected side, especially the SN pars compacta, showed a marked increase in iron staining. Our study indicates that an injury to the nigrostriatal system by MPTP injection can induce iron accumulation in the SN.

Efficient production of recombinant human factor VIII by co-expression of the heavy and light chains.

We have developed a high-level expression system for human blood coagulation factor VIII (FVIII) consisting of a 90 kDa heavy (H-)chain and an 80 kDa light (L-)chain. Two expression plasmids were prepared, one expressing the H-chain and the other expressing the L-chain. These recombinant plasmids were designed to produce each chain linked to short additional amino acid residues derived from the FVIII precursor sequence. Furthermore, Kozak's translation initiation consensus sequence was introduced into the start codon for the H-chain. These modifications have dramatically increased the levels of expression of these chains. Chinese hamster ovary (CHO) cells co-transfected with these two recombinant plasmids were subjected to gene amplification and cloning. The final cell line, designated CTC-CF8, secretes 15 IU/day/10(6) cells of active FVIII which is indistinguishable from plasma-derived FVIII in its structure and biochemical properties. This system is suitable for large-scale production of pathogen-free recombinant human FVIII which can be used for the treatment of haemophilia A patients.