Takuya Kawahata

ANTI-HIV-1 AND ANTI-HIV-1-PROTEASE SUBSTANCES FROM GANODERMA LUCIDUM

A new highly oxygenated triterpene named ganoderic acid alpha has been isolated from a methanol extract of the fruiting bodies of Ganoderma lucidum together with twelve known compounds. The structures of the isolated compounds were determined by spectroscopic means including 2D-NMR. Ganoderiol F and ganodermanontriol were found to be active as anti-HIV-1 agents with an inhibitory concentration of 7.8 micrograms ml-1 for both, and ganoderic acid B, ganoderiol B, ganoderic acid C1, 3 beta-5 alpha-dihydroxy-6 beta-methoxyergosta-7,22-diene, ganoderic acid alpha, ganoderic acid H and ganoderiol A were moderately active inhibitors against HIV-1 PR with a 50% inhibitory concentration of 0.17-0.23 mM.

Anti-HIV-1 phorbol esters from the seeds of Croton tiglium

Five phorbol diesters, together with three known ones, were isolated from a MeOH extract of the seeds of Croton tiglium, and their structures were determined by spectroscopic methods and selective hydrolysis of acyl groups. These compounds were assessed for their abilities to inhibit an HIV-induced cytopathic effect (CPE) on MT-4 cells and to activate protein kinase C (PKC) associated with tumor-promoting action. 12-O-Acetylphorbol-13-decanoate and 12-O-decanoylphorbol-13-(2-methylbutyrate) effectively inhibited the cytopathic effect of HIV-1 [complete inhibitory concentration (IC100) values of 7.6 ng/ml and 7.81 microg/ml, and minimum cytotoxic concentration (CC0) value of 62.5 and 31.3 microg/ml, respectively]; however, 12-O-acetylphorbol-13-decanoate showed no activation of PKC at concentrations of 10 and 100 ng/ml. 12-O-Tetradecanoylphorbol-13-acetate (TPA) was found to be not only the most potent inhibitor of HIV-1-induced CPE (IC100 value of 0.48 ng/ml), but also the most potent activator of PKC (100% activation at 10 ng/ml).

Inhibitory effects of Sudanese plant extracts on HIV-1 replication and HIV-1 protease.

Forty‐eight methanol and aqueous extracts from Sudanese plants were screened for their inhibitory activity on viral replication. Nineteen extracts showed inhibitory effects on HIV‐induced cytopathic effects (CPE) on MT‐4 cells. The extracts were further screened against HIV‐1 protease (PR) using an HPLC assay method. Of the tested extracts, the methanol extracts of Acacia nilotica (bark and pods), Euphorbia granulata (leaves), Maytenus senegalensis (stem‐bark) and aqueous extracts of A. nilotica (pods) and M. senegalensis (stem‐bark) showed considerable inhibitory effects against HIV‐1 PR. Inhibitory principles were isolated from M. senegalensis and their activities were also discussed. Copyright

New Ceftriaxone- and Multidrug-Resistant Neisseria gonorrhoeae Strain with a Novel Mosaic penA Gene Isolated in Japan

ABSTRACT We have characterized in detail a new ceftriaxone- and multidrug-resistant Neisseria gonorrhoeae strain (FC428) isolated in Japan in 2015. FC428 differed from previous ceftriaxone-resistant strains and contained a novel mosaic penA allele encoding a new mosaic penicillin-binding protein 2 (PBP 2). However, the resistance-determining 3′-terminal region of penA was almost identical to the regions of two previously reported ceftriaxone-resistant strains from Australia and Japan, indicating that both ceftriaxone-resistant strains and conserved ceftriaxone resistance-determining PBP 2 regions might spread.

Synthesis, anti-HIV and anti-oxidant activities of caffeoyl 5,6-anhydroquinic acid derivatives

In our continued research on chlorogenic acid analogues and derivatives with improved bioactivity, we have synthesized some caffeoyl 5,6-anhydroquinic acid derivatives. The 1,7 acetonides of chlorogenic acid (15), and of the mono-caffeoyl 5,6-anhydroquinic acids (7-8) showed appreciable anti-HIV activity. The 3,4-dicaffeoyl 5,6-anhydroquinic acid (12) exhibited an anti-HIV activity twice as that of 3,5-dicaffeoylquinic acid (22). The caffeoyl 5,6-anhydroquinic acid derivatives displayed potent anti-oxidant activities. The mono-caffeoyl 5,6-anhydroquinic acids (10-11) were more than twice stronger than chlorogenic acid (21) on SOD-like activity.

Recent diversity of human immunodeficiency virus type 1 in individuals who visited sexually transmitted infection-related clinics in Osaka, Japan

By human immunodeficiency virus type 1 (HIV-1) antibody screening of people who visited sexually transmitted infection (STI)-related clinics (venereology, urology, and gynecology) and were considered to conduct high-risk sexual activities for HIV-1 infection in Osaka, Japan, during 1992 to 2004, a total of 54 HIV-1 infected individuals (51 Japanese males and 3 non-Japanese females) were identified. Based on the sequencing at env-C2V3 and pol regions, Japanese males were mostly of subtype B (50/51 cases), with the one remaining case being a recombinant circulating form, CRF01_AE, while 3/3 viruses in non-Japanese females were of CRF01_AE. Analysis of subtype B cases since 2001 showed that these viruses became wider in their genetic variation, including amino acid insertions and also deletions, than that of the cases before 2000. Thus, it was suggested that HIV-1 spreading in Osaka has been increasing in genetic variability. Although all these infected individuals were first recognized to be infected with HIV-1 by our screening, some of them were carriers of HIV-1 with drug-resistant pol sequences, indicating that they could be infected with drug-resistant HIV-1 mutants.

Inhibition of Octapeptide N-Myristoylation by Acyl Amino Acids and Acyl Alkanolamines

Several acyl amino acids and acyl alkanolamines were prepared and screened for their inhibition of octapeptide N-myristoylation and HIV-1 replication in MT-4 cells. Of the 62 acyl derivatives tested, N-myristoyl-O-caproyl-L-serine, N-myristoyl-O-caproyl-D-serine and N-decanoyl-O-myristoyl-L-serine were found to be uncompetitive inhibitors of N-myristoylation, but did not prevent HIV-induced cytopathicity in MT-4 cells. However, other acyl derivatives such as N-3-hydroxymyristoyl ethanolamine, N-3-hydroxymyristoyl-D-serine and N-myristoyl-L-cysteine, which did not inhibit N-myristoylation, suppressed the cytopathicity in the infected cells. The acyl derivatives described here may serve as lead compounds for antiviral agents.

A cluster of rapid disease progressors upon primary HIV-1 infection shared a novel variant with mutations in the p6gag/pol and pol/vif genes.

Few studies have described the etiologic factors associated with rapid AIDS onset during primary HIV-1 infection. Our molecular epidemiological study identified a cluster of individuals infected with HIV-1 variants characterized by novel mutations in the p6gag/pol and pol/vif genes during 2011 and 2013 in Osaka, Japan. Individuals positive for the novel HIV-1 variant showed rapid disease progression, suggesting a role of viral mutations in the fostering of the clinical course of HIV-1 infection.

Cases of HIV type 1 acute infection at STI-related clinics in Osaka.

Since 1992 we have investigated HIV antibodies in persons with a venereal disease who worked for a sex business or engaged in sexual behavior with a high risk of HIV infection at five clinics of venereology, urology, and gynecology in Osaka Prefecture. Starting at the end of 2000, we performed a nucleic acid-amplification test (NAT) on antibody-negative samples with the aim of detecting cases in the window period covering the early phase of infection. Three cases that were thought to be in this phase were found in 2006. All were confirmed to be positive in an NAT, although they were negative in initial screening for HIV performed using the IC method. Gene analysis of the env-C2V3 region of HIV-1 showed that the three samples had different origins.

Comparative evaluation of the GeeniusTM HIV 1/2 Confirmatory Assay and the HIV-1 and HIV-2 Western blots in the Japanese population

Accurate diagnosis of earlier HIV infection is essential for treatment and prevention. Currently, confirmation tests of HIV infection in Japan are performed using Western blot (WB), but WB has several limitations including low sensitivity and cross-reactivity between HIV-1 and HIV-2 antibodies. To address these problems, a new HIV testing algorithm and a more reliable confirmation and HIV-1/2 differentiation assay are required. The Bio-Rad Geenius™ HIV-1/2 Confirmatory Assay (Geenius) has recently been approved and recommended for use in the revised guidelines for diagnosis of HIV infection by the Center for Disease Control and Prevention (USA). We made comprehensive comparison of the performance of Geenius and the Bio-Rad NEW LAV BLOT 1 and 2 (NLB 1 and 2) which are WB kits for HIV-1 and HIV-2, respectively, to examine if Geenius is a suitable alternative to these WB assays which are now being used in HIV testing in Japan. A total of 166 HIV-1 positive samples (146 from patients with established HIV-1 infection and 20 from patients with acute infection), five HIV-1 seroconversion panels containing 21 samples and 30 HIV-2 positive samples were used. In addition, a total of 140 HIV negative samples containing 10 false-positives on screening tests were examined. The sensitivity of Geenius and NLB 1 for HIV-1 positive samples was 99.3% and 98.6%, respectively. Geenius provided more positive results in the samples from acute infections and detected positivity 0 to 32 days earlier in seroconversion panels than NLB 1. NLB 2 gave positive results in 12.3% of HIV-1 positive samples. The sensitivity of both Geenius and NLB 2 for HIV-2 positive samples was 100%. The specificity of Geenius, NLB 1 and NLB 2 was 98.5%, 81.5% and 90.0%, respectively. Geenius is an attractive alternative to WB for confirmation and differentiation of HIV-1 and HIV-2 infections. The adaptation of Geenius to the HIV testing algorithm may be advantageous for rapid diagnosis and the reduction of testing costs.