Abstract: Nucleoside analogues having a ring-open structure, of general formula: ##STR1## where R and R' may be hydrogen, silyl groups, substituted alkyl groups, benzyl groups and the like, and X is an optionally substituted pyrimidine or triazine base, exhibit anti-viral activities e.g. against herpes simplex virus and cytomegalo-virus at non-toxic levels.

Abstract: Combinations of 9-[[2-hydroxy-1-(hydroxymethyl)-ethoxy]methyl]guanine or a pharmaceutically acceptable salt thereof, and interferon show synergy in their activity against herpes virus infections.

Abstract: 2-(N,N-dialkylaminomethylene)-9-[[2-hydroxy-1-(hydroxymethyl)-ethoxy]methyl ]guanine either alone or in admixture with interferon is active in treatment of herpes simplex type 1 viral infections.

Abstract: The novel nucleoside analogue 9-[1-(1,3-diacetoxy-2-propoxy)-2-acetoxy]ethylguanine has the effect of stimulating the rate of growth of certain viruses, particularly influenza viruses, so that culturing virally infected cells in the presence of this compound substantially decreases the time required for diagnosis and typing of the virus, ready for administration of appropriate anti viral measures.

Abstract: An apparatus for the stepwise synthesis of polynucleotides in which the polynucleotide chains are extended in stepwise fashion from a modified form of polymer support to which the first unit is linked comprises a reaction column containing the polymer supported product and acting as the reaction vessel, and a series of reaction bottles all connected to the reaction column by means of a fluid flow conduit to which the vessels make connection via two-way valves arranged in series. The farthest upstream vessel of the series contains reaction solvent, used for washing purposes and the like. The most downstream of the reaction vessels contain nucleotide reagents.

Abstract: Nucleoside analogues having a ring-open structure, of general formula: ##STR1## where R and R' may be hydrogen, silyl groups, substituted alkyl groups and the like, and B is a base such as adenine, have been shown to exhibit anti-viral and other biological activities at non-toxic levels. Also provided are phosphate-linked dinucleotide compounds of similar structures.

Abstract: Silylated arabino-base compounds of the general formula: ##STR1## in which B represents an optionally substituted purine or pyrimidine base (cytosine, guanine, uracil, thymine or adenine) and one at least of R, R' and R" is alkylsilyl, the others being hydrogen, show activity as antiviral agents, especially in combatting herpes simplex virus. The preferred alkylsilyl group is tert. butyldimethylsilyl.