Cycloartanes from the red alga Galaxaura sp.
Six cycloartane triterpenes have been isolated from the red alga Galaxaura sp. The new structures (galaxaurols A–E) were determined to be methyl 3β-hydroxy-23-oxocycloart-24-en-29-oate (2), methyl 23(E)-3β-hydroxy-25-methoxycycloart-23-en-29-oate (3), methyl 23(E)-3β-hydroxycycloarta-23,25-dien-29-oate (4), 23(E)-25-methoxycycloart-23-en-3β,29-diol (5), and cycloart-24-en-3β,23α,29-triol (6), respectively.
Cycloartane derivatives from Tillandsia usneoides
Investigation of the extract of Tillandsia usneoides afforded 26 cycloartane derivatives, including the following novel ones:  (22E)-25,26,27-trisnor-3-oxocycloart-22-en-24-al, (24E)-3-oxocycloart-24-en-26-al, 24-hydroxycycloart-25-en-3-one, (23E)-25-methoxycycloart-23-en-3-one, (23E)-25-hydroperoxycycloart-23-en-3-one, 25,26,27-trisnor-24-hydroxycycloartan-3-one, methyl (24E)-26-carboxy-3,4-seco-cycloart-4(29),24-dien-3-oate, methyl (23E)-25-hydroxy-3,4-seco-cycloart-23-en-3-oate, methyl (23E)-25-methoxy-3,4-seco-cycloart-23-en-3-oate, and methyl 24-hydroxy-3,4-seco-cycloart-25-en-3-oate. The structures were assigned on the basis of spectral data.
A Vector Space Model for Syntactic Distances Between Dialects
Syntactic comparison across languages is essential in the research field of linguistics, e.g. when investigating the relationship among closely related languages. In IR and NLP, the syntactic information is used to understand the meaning of word occurrences according to the context in which their appear. In this paper, we discuss a mathematical framework to compute the distance between languages based on the data available in current state-of-the-art linguistic databases. This framework is inspired by approaches presented in IR and NLP.