Alzheimer's disease (AD) is a neurodegenerative disease,which is insidious onset and progressive.The pathological features of AD include senile plaques composed of amyloid β (Aβ) and neurofibrillary tangles composed of Tau protein.Aβ and Tau protein targeted imaging agents,which make a non-invasive and high specificity diagnosis,might be useful for early diagnosis,efficacy monitoring and drug evaluation for AD.This review summarizes the progress and clinical applications of those agents in AD.

Plant diterpenoids are widely distributed and abundant natural products with diverse structures and functions in nature, which have been commonly used in pharmaceutical, agricultural and industrial production. In recent years, plant diterpenoids have attracted increasing attention, including their biosynthetic pathways, transcriptional regulatory networks, and biological functions. Herein, the biosynthetic pathways of diterpenoids are summarized in a modular fashion. Further, the regulatory network between diterpene biosynthesis and environmental factors is reviewed. Insights into diterpene metabolism may drive elucidation of complex active diterpene pathways and serve as a knowledge repository for metabolic engineering and cell factory construction.
Plants, Medicinal/metabolism* ; Diterpenes/chemistry* ; Metabolic Engineering ; Biosynthetic Pathways ; Biological Products/metabolism*