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Int J Biol Macromol. 1997 Apr;20(2):97-105.
Antiherpetic and anticoagulant properties of carrageenans from the red seaweed Gigartina skottsbergii and their cyclized derivatives: correlation between structure and biological activity.

Carlucci MJ, Pujol CA, Ciancia M, Noseda MD, Matulewicz MC, Damonte EB, Cerezo AS.

Departamento de Quimica Biologica, CIHIDECAR-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina.

The antiviral activity against herpes simplex virus types 1 and 2 of kappa/l-, partially cyclized mu/v-, and lambda-carrageenans isolated from the red seaweed Gigartina skottsbergii and their cyclized derivatives was analyzed. lambda-Carrageenans and the partially cyclized mu/v-carrageenan were the most potent inhibitors of herpes viruses (including acyclovir-resistant variants and clinical isolates), with IC50 values lower than 1 microgram ml-1 against both serotypes and selectivity indices higher than 10(3). kappa/l-Carrageenans were slightly less effective than the other two types with IC50 values in the range 1.6-4.1 micrograms ml-1. Antiherpetic activity was directly correlated to the amount of alpha-D-galactose 2,6-disulfate residues in the natural carrageenans. The cyclization of the alpha-D-galactose 6-sulfate and 2,6-disulfate units into 3,6-anhydro-alpha-D-galactose and 3,6-anhydro-alpha-D-galactose 2-sulfate residues in these polysaccharides, in general, lowers the antiherpetic activity of the derivatives with respect to the natural carrageenans. Some carrageenans showed a very reduced anticoagulant activity only at concentrations that were considerably higher than the IC50, whereas others were totally devoid of anticoagulant properties. Among natural carrageenans, the mu/v-type IC3 shows the best relationship between antiviral efficacy and lack of anticoagulant action, resulting a very promising compound.

online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9184941&dopt=Abstract

charite.de

Cytomegalovirus (CMV) hepatitis is described as the most frequent manifestation of CMV tissue invasive disease after liver transplantation. Its correlation with HLA-matching, hepatic artery thrombosis, and chronic rejection is still controversial. Risk factors, incidence, clinical course, and complications of CMV hepatitis were retrospectively analyzed in a 12-year series of 1,146 consecutive liver transplantations in 1,054 patients. All patients received only low-dose acyclovir but no gancyclovir prophylaxis. CMV infection was diagnosed by viral culture, pp65 antigenemia, or by polymerase chain reaction (PCR). CMV hepatitis was proven by liver biopsy. Treatment of CMV disease consisted of intravenous ganciclovir for a minimum of 14 days. Long-term follow-up of patients included monthly routine laboratory values and routine liver biopsies 1, 3 and 5 years after transplantation. CMV hepatitis was a rare event after liver transplantation, with a total incidence of 2.1% (24 cases). It was significantly more frequent in CMV seronegative (5.2%) than in seropositive recipients (0.7%). The leading indication in patients with CMV hepatitis was HCV cirrhosis (n = 8). The maximum number of pp65 positive white blood cells was 82 +/- 23 per 10,000 cells. Most courses manifested as isolated hepatitis; only 2 patients had disseminated disease. Nine of 24 patients had received OKT3 monoclonal antibodies because of steroid-resistant rejection before CMV hepatitis. In seronegative patients with CMV hepatitis, 71% revealed 1 or 2 HLA DR matches, in contrast to 32% in patients without CMV hepatitis. One-, 3-, and 5-year graft survival was 78%, 65%, and 59% in patients with CMV hepatitis compared with 88%, 81%, and 79% in patients without. Chronic rejection was observed in one patient, but already before onset of CMV hepatitis. Beneath D+R-constellation and OKT3 treatment as risk factors, HLA DR-matched grafts and HCV seem to favor manifestation of CMV hepatitis after liver transplantation. Long-term complications of CMV hepatitis were not observed, and especially no correlation with chronic rejection was found.

online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12474153&dopt=Abstract

yahoo.com

A simple and reliable spectrophotometric method has been developed for the determination of acyclovir in pharmaceutical formulations. The method is based on its oxidative coupling reaction with 3-methylbenzothiazolin-2-one hydrazone (MBTH) in the presence of FeCl3 as an oxidant to produce deep-green colored species measurable at 616 nm. The absorbance-concentration plot is linear over the range 20-200 microg ml(-1) with minimum detectability of 1.06 microg ml(-1) (4.71 x 10(-6) M). The molar absorptivity was 9.41 x 10(2) l mol(-1) cm(-1) with correlation coefficient (n = 7) of 0.9998. The different experimental parameters affecting the development and stability of the color were studied carefully and optimized. The proposed method was applied successfully to the determination of acyclovir in its dosage forms. The percentage recoveries +/-SD (n = 9) were 98.63 +/- 0.34, 99.61 +/- 0.58, 99.35 +/- 0.58 and 99.72 +/- 0.86 for tablets, ophthalmic ointment and cream, respectively. A proposal of the reaction pathway was presented.

online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12484534&dopt=Abstract












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