https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

Phytochemical screening, total phenolics and antioxidant activities of bark and leaf extracts of Goniothalamus velutinus (Airy Shaw) from Brunei Darussalam

Naturally occurring aristolactams, aristolochic acids and dioxoaporphines and their biological activities

Because Lewis structures provide a direct connection between molecular structure and properties, the ability to construct and use them is an integral component of many chemistry courses. Although a great deal of time and effort has been dedicated to development of “foolproof” rules, students still have problems with the skill. What is more, many students fail to connect the skill with the reasons for learning it. In fact, it appears that conventional instructional practices involved in teaching Lewis structures are in direct conflict with much of what we know about how people learn. In support of this assertion, we present the results of a mixed-methods study designed to investigate how students at all levels draw Lewis structures, and how students perceive the utility of Lewis structures. We offer suggestions for alternative methods of developing this skill in order to provide students with an approach to meaningful learning.

Lost in Lewis Structures: An Investigation of Student Difficulties in Developing Representational Competence

Thirty-one bioactive styryl-lactones, with six different basic skeletons, have been isolated from Goniothalamus species. Aspects of their isolation, structural elucidation, biogenesis and biological activity are reviewed. Copyright © 1999 John Wiley & Sons, Ltd.

Styryl-lactones from Goniothalamus species— A review

5-Acetyl goniothalamin, a styryl dihydropyrone from Goniothalamus uvaroides

Phenanthrene lactams from Goniothalamus velutinus

A simple step-by-step approach for deriving Lewis structures for students studying introductory chemistry.

Drawing Lewis structures: A step-by-step approach

Two new cytotoxic tetronic acid derivatives with a rearranged drimane skeleton [1a and 1b], were isolated from the sponge Dactylospongia elegans, along with smenospongic acid [3], illimaquinone [4], dactylospongenones A, B, C, and D [5], and dictyoceratin C [6]. The structures of 1a and 1b were elucidated by spectroscopic and chemical methods. Treatment of 1 with base gave smenospongic acid [3], suggesting that this latter compound is an end-product of D. elegans metabolism. A biogenetic route from furoterpenes to the tetronic acids [1a and b] and smenospongic acid [3] is proposed.

Siraj Omar

Papers

5-Acetyl goniothalamin, a styryl dihydropyrone from Goniothalamus uvaroides

Phenanthrene lactams from Goniothalamus velutinus

Drawing Lewis structures: A step-by-step approach

Dactyltronic acids from the sponge Dactylospongia elegans

Malaysiatin, the first cyclic heptapeptide from a marine sponge