Related Experiment Video
Updated: May 27, 2026
07:59
A Customizable Approach for the Enzymatic Production and Purification of Diterpenoid Natural Products
Published on: October 4, 2019
Sesquiterpene synthases: passive catalysts or active players?
David J Miller1, Rudolf K Allemann
1School of Chemistry, Cardiff University, United Kingdom.
Natural Product Reports
|November 10, 2011
Summary
Sesquiterpene synthases (SPS) are enzymes that create diverse natural products. Recent studies suggest these enzymes play active, multifaceted roles in complex biosynthetic reactions, challenging previous passive template theories.
Area of Science:
- Biochemistry
- Organic Chemistry
- Natural Product Synthesis
Background:
- Sesquiterpene synthases (SPS) catalyze the conversion of farnesyl diphosphate into a wide array of structurally diverse sesquiterpenes.
- These enzymes are crucial for generating natural products with varied biological functions and applications.
- Historically, SPS were thought to act as passive stereochemical templates for these reactions.
Purpose of the Study:
- To review recent research on the structure, function, and reaction mechanisms of sesquiterpene synthases.
- To challenge the passive template model by highlighting the active roles of these enzymes.
Main Methods:
- Literature review of recent studies on sesquiterpene synthases.
- Analysis of enzyme structure, function, and reaction mechanisms.
- Synthesis of evidence to support active enzyme roles.
Main Results:
- Sesquiterpene synthases exhibit significant diversity in structure and catalytic outcomes.
- Evidence suggests these enzymes actively influence reaction pathways and stereochemical outcomes.
- The complexity of sesquiterpene biosynthesis points to multifaceted enzymatic roles.
Conclusions:
- Sesquiterpene synthases play active, multifaceted roles in the biosynthesis of sesquiterpenes.
- Enzyme structure and mechanism are critical determinants of the vast structural diversity observed.
- Revisiting the role of SPS provides new insights into complex natural product biosynthesis.
Related Concept Videos
01:26Photochemical Electrocyclic Reactions: Stereochemistry
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
01:22Heterogeneous Catalysis
Heterogeneous catalysis involves a catalyst in a different phase from the reactants. It is a process where the catalyst and the reactants are in distinct phases, typically solid and gas or liquid.Most heterogeneous catalysts are metals, metal oxides, or acids. The list includes transition metals like iron (Fe), cobalt (Co), nickel (Ni), palladium (Pd), platinum (Pt), chromium (Cr), manganese (Mn), tungsten (W), silver (Ag), and copper (Cu). These metals possess partially vacant d orbitals that...
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
01:17Thermal Electrocyclic Reactions: Stereochemistry
The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.
01:46The Calvin Benson Cycle
Ribulose 1,5- bisphosphate carboxylase/oxygenase (RuBisCo) is a critical enzyme that catalyzes carbon dioxide assimilation during photosynthesis. However, it is an inefficient enzyme, having an extremely slow catalytic rate. A typical enzyme can process about a thousand molecules per second; however, RuBisCo fixes only around three-carbon dioxides per second. Photosynthetic cells compensate for this slow rate by synthesizing very high amounts of RuBisCo, making it the most abundant single...
02:34Enzymes
Inside living organisms, enzymes act as catalysts for many biochemical reactions involved in cellular metabolism. The role of enzymes is to reduce the activation energies of biochemical reactions by forming complexes with its substrates. The lowering of activation energies favor an increase in the rates of biochemical reactions.
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...