The present invention relates to methods and compositions for preparing biologically important nucleoside analogues containing 1,3-dioxolane sugar rings. In particular, this invention relates to the stereoselective synthesis of the beta (cis) isomer by glycosylating the base with an intermediate of formula (II) below a temperature of about -10.degree. C. ##STR1## wherein R.sub.1 and L are defined herein.

The present invention relates to a process for producing predominantly pure cis nucleoside analogues of formula (I), wherein X is S, or O; Y is S, CH.sub.2, O or CH(R); wherein R is azido or halogen; and R.sub.2 is a purine or pyrimidine base; via the coupling of a silylated purine or pyrimidine base in the presence of an appropriate Lewis acid with a bicyclic intermediate of formula (III) wherein Z is S or O; followed by conversion of the resulting intermediate of formula (II) to an alkyl ester...

The present invention relates to highly diastereoselective processes for production of cis-nucleosides and nucleoside analogues and derivatives in high optical purity, and intermediates useful in those processes.

This invention relates to a naphthoquinone derivatives, to processes and to intermediates for preparing these derivatives, to pharmaceutical composition and to the use of these derivatives as antitumor agents in mammals.

The present invention relates to highly diastereoselective processes for production of cis-nucleosides and nucleoside analogues and derivatives in high optical purity and intermediates useful in those processes.

There is provided novel 2-substituted-4-substituted-1,3-dioxolanes which are particularly useful as antiviral agents.

Peptides are provided which are suitable for the treatment of pain and gastro-intestinal disorders, such as diarrhea, and are represented by the structure: ##STR1## where values for the substituents and n are disclosed herein. Methods for preparing these peptides by solution and solid phase syntheses are also provided. Pharmaceutical compositions utilizing these peptides in a pharmaceutically effective amount and methods of treatment using them are provided.

There is provided cyclic peptides of the general formulae: ##STR1## wherein x represents an amino acid sequence from position 585 to 604 (gp41-HIV-1) such amino acid sequences being characterized by at least one of a lysine at position 586 or a lysine at both positions 585 and 586; x.sup.2 represents an amino acid sequence from position 585 to 604 (gp41-HIV-1); y represents an amino acid sequence from position 612 to 629 (gp41-HIV-1); e and f represent one or more epitopes; and a and b represent...

Polycyclic alkaloids of formula (I), wherein R.sub.1 is H, C.sub.1-6 alkyl, or C.sub.6-12 aryl optionally substituted with polar groups; R.sub.2 and R.sub.3 are independently H, OH, C.sub.1-6 alkyl, --C(NH)--NH.sub.2, a positively charged group, or C.sub.7-13 aralkyl optionally substituted with NH.sub.2, OH, C.sub.1-6 alkyl, or halogen; or R.sub.2 and R.sub.3 together form a 5 to 6 member ring optionally incorporating a heteroatom; R.sub.4 is H, C.sub.1-6 alkyl, OR.sub.6, SR.sub.6, or N(R.sub.6)...

The present invention relates to peptides having an immunomodulatory activity. The present invention is concerned with the tetrapeptide H-Lys-Asn-Pro-Tyr-OH (SEQ.ID NO:1) and analogues thereof as immunomodulators. The present invention also includes the use of such peptides as vaccine adjuvant.