introduction lab chemistry

HOW TO WRITE THE INTRODUCTION SECTION

Example from research paper:

Monoterpenoid Essential Oils are Not of Mevalonoid Origin

Wolfgang Eisenreieh j, Silvia Sagner +, Meinhart H. Zenk + and Adelbert Bacher j*

Tetrahedron Letters, Vol. 38, No. 22, pp. 3889-3892, 1997

Monoterpenes are a major class of secondary compounds of considerable economic value

occurring primarily in higher plants but also in some animals and microorganisms. Condensation

of isopentenyl pyrophosphate (IPP) with dimethylallyl pyrophosphate (DMAPP) furnishes

geranyl pyrophosphate which, by action of monoterpene cyclases, leads to various C]o-skeletal

types. 1 It is generally assumed that plant-derived monoterpenoids are of mevalonoid origin,

however, labelled mevalonic acid is only poorly incorporated into the target terpenoids. 2 This

led to considerable doubts as to the relevance of the mevalonoid pathway for the formation of

monoterpenoids in higher plants. 2 Recently, Arigoni, Schwarz and their coworkers 3

demonstrated that feeding of ~3C-labelled glucose to Ginkgo biloba embryos led to a labelling

pattern in the diterpene ginkgolide A, which is incompatible with the mevalonoid origin of this

terpenoid. Feeding of [U-'3C6] - and [l- ~3C]glucose to a cell culture of Taxus chinensis

demonstrated that the diterpene taxuyurmanine C is also not of mevalonoid origin. 4 Recent

studies on chlorophyll and carotenoids using Lemna gibba, Hordeura vulgare, and Daucus

carota showed similar results. In this contribution we extend our feeding experiments to

monoterpenes using [U-]3C6]- and [1)ac]glucose.

The introduction is the first section of a paper, and its purpose is to describe the general topic.

In this paper the authors are describing a discovery related to monoterpenoid, therefore the first

section includes:

o What monoterpenoids are

o Some recent literature about the topic

o Limitations of the current literature on the subject (that explains why the authors

conducted the research in the first place)

o A brief sentence summarizing what the paper will focus on

LET’S SEE IN DETAILS

Monoterpenes are a major class of secondary compounds of considerable economic value

occurring primarily in higher plants but also in some animals and microorganisms. Condensation

of isopentenyl pyrophosphate (IPP) with dimethylallyl pyrophosphate (DMAPP) furnishes

geranyl pyrophosphate which, by action of monoterpene cyclases, leads to various C]o-skeletal

types.

In these first few sentences the author gives a little bit of background about the subject

of the paper: monoterpenes. He describes what they are, and he refers to a literature

paper (the superscript number you see).

It is generally assumed that plant-derived monoterpenoids are of mevalonoid origin, however,

labelled mevalonic acid is only poorly incorporated into the target terpenoids. 2 This led to

considerable doubts as to the relevance of the mevalonoid pathway for the formation of

monoterpenoids in higher plants. 2 Recently, Arigoni, Schwarz and their coworkers 3

demonstrated that feeding of ~3C-labelled glucose to Ginkgo biloba embryos led to a labelling

pattern in the diterpene ginkgolide A, which is incompatible with the mevalonoid origin of this

terpenoid. Feeding of [U-'3C6] - and [l- ~3C]glucose to a cell culture of Taxus chinensis

demonstrated that the diterpene taxuyurmanine C is also not of mevalonoid origin. 4 Recent

studies on chlorophyll and carotenoids using Lemna gibba, Hordeura vulgare, and Daucus

carota showed similar results.

This is the longest section of the introduction. The author is more specific about the role

of the monoterpenes, in particular he cites several literature papers that are related to the

topic he worked on. The purpose is to give a detailed background of the work that has

already been done on the topic, and also highlight the limitations of the current research.

In this contribution we extend our feeding experiments to monoterpenes using [U-]3C6]- and

[1)ac]glucose.

Brief sentence explaining the novelty of their work and what is the main topic of the

paper.