Nigel B. Perry

Alkaloids from the antarctic sponge Kirkpatrickia varialosa. : Part 1: Variolin b, a new antitumour and antiviral compound

Abstract Variolin B (1), a new type of pyridopyrrolopyrimidine alkaloid with antitumour and antiviral properties, has been isolated from the Antarctic sponge Kirkpatrickia varialosa, and its structure determined by X-ray crystallography. A degradation product, variolin D (2), has been identified from its spectroscopic data.

Alkaloids from the antarctic sponge Kirkpatrickia varialosa. Part 2: Variolin A and N(3′)-methyl tetrahydrovariolin B

Abstract Two pyridopyrrolopyrimidine alkaloids, variolin A (2) and N(3′)-methyl tetrahydrovariolin B (3), have been isolated from the Antarctic sponge Kirkpatrickia varialosa, and their structures determined by X-ray crystallography and interpretation of spectral data respectively. N(3′)-Methyl tetrahydrovariolin B (3) is moderately cytotoxic and showed antifungal activity, while variolin A (2) is weakly cytotoxic.

Biological activity in New Zealand marine organisms

The incidence and significance of antiviral and cytotoxic activity in a New Zealand collection of marine organisms has been investigated. Several compounds with potent biological activities have been isolated and characterised.

Occurrence of variabilin in New Zealand sponges of the order dictyoceratida

Abstract Sixty-three collections of New Zealand sponges of the order Dictyoceratida were analysed for the presence of the sesterterpene tetronic acid variabilin. This compound was found only in the morphologically similar genera Ircinia, Psammocinia and Sarcotragus.

Biologically active compounds from Ozothamnus leptophyllus

Abstract A crude extract from a New Zealand native plant, Ozothamnus leptophyllus, was shown to possess antifungal activity. Flavonoids, mainly chalcones in the leaf exudate, were isolated, some of which possessed antiviral as well as antifungal activity. These flavanoids are excreted by glandular trichomes and form quasi‐crystalline deposits on the abaxial side of the leaves. 2’,4’,6‐Trihydroxy‐chalcone was found to be active against both Polio virus (Pfizer vaccine strain) and Herpes simplex type 1 (ATCC VR 733); it was also responsible for anti‐dermatophytic activity against Trichophyton mentagrophytes. 2’,4‐Dihydroxy‐4‐methoxy‐dihydrochalcone was also active against both viruses.

Implementing functional languages on object-oriented virtual machines

Hosting functional languages in object-oriented environments, such as the Java Virtual Machine and Microsofts Common Language Infrastructure, so that they inter-operate well with other languages presents a number of problems. In the paper the authors introduce Mondrian, a functional language specifically designed for such environments, and describe the decisions and trade-offs in its design. The paper concentrates on the high-level design decisions made for Mondrian. The authors cover the design of a type system which is part-way between the traditional parametric polymorphism and sum type models of functional languages and the sub-type models used by the virtual machines. Next they discuss how function values and nonstrict evaluation can be provided while supporting easy inter-working with strict object-oriented languages. They briefly comment on the low-level implementation of Mondrian and conclude with a multi-language example using Mondrian and C#. The work shows that, with appropriate design, it is possible to combine functional and object-oriented programming without losing the unique benefits of each.