Modern Methods of
Extraction and Identification
of Natural Compounds
Syllabus
▪ Introduction and history of extraction and identification of natural compounds
▪ Green extraction – definition and basic principles
▪ Renewable plant resources
▪ Alternative solvents
▪ Reduction of energy consumption
▪ Modern analytical techniques for identification of natural compounds
▪ NMR spectroscopy
▪ High-resolution mass spectrometry (HRMS)
▪ Hyphenated techniques
History
▪ Sumerian text 4000–2100 BC (myrtle, licorice, barley, pine tree resin, …)
History
▪ The Ebers Papyrus, Egypt, 2900–1500 BC (700 drugs)
Formulas
▪ gargles, snuffs, poultices, infusions, pills, and ointments
▪ beer, milk, wine, and honey as vehicles
Primary/secondary metabolites
Methods for recovery of secondary metabolites
Ancient olive oil pressing
Israel Tour 2015 - Nazareth Village olive oil pressing - YouTube
Modern olive oil pressing
https://www.youtube.com/watch?v=aieNV3V4b_s
Modern pressing methods
Extraction
▪ Batch extraction (maceration, digestion, infusion, decoction)
▪ Continuous extraction (percolation, Soxhlet extraction)
• Ultrasound assisted extraction (UAE)
• Microwave assisted extraction (MAE)
• Pulsed electric field extraction (PEF)
• Pressurized liquid extraction (PLE)
• Supercritical fluid extraction (SFE)
• Enzyme assisted extraction (EAE)
• Hydro distillation and steam distillation
Batch extraction
Maceration Digestion Infusion Decoction
Alcohol or water Usually water Usually water Usually water
Room temperature 40–50°C
Boiling water
(without heating)
Drug is boiled
in water
Extraction for
several days
Extraction for
several days
Extraction for
15 minutes
Extraction for
30 minutes
Percolation
How Do Drip Coffee Machines Work? - Making Coffee Explained - YouTube
Soxhlet extraction
Ultrasound assisted extraction (UAE)
Ultrasound assisted extraction (UAE)
CHEMAT, Farid, et al. Ultrasound assisted extraction of food and natural products. Mechanisms, techniques,
combinations, protocols and applications. A review. Ultrasonics sonochemistry, 2017, 34: 540-560.
CHEMAT, Farid, et al. Ultrasound assisted extraction of food and natural products. Mechanisms, techniques,
combinations, protocols and applications. A review. Ultrasonics sonochemistry, 2017, 34: 540-560.
Ultrasound assisted extraction (UAE)
Microwave assisted extraction (MAE)
Closed Vessel Microwave-Assisted Extraction System | ETHOS EX - YouTube
Comparison of digestion, UAE, and MAE
Pulsed electric field extraction (PEF)
Pressurized liquid extraction (PLE)
Supercritical fluid extraction (SFE)
Enzyme assisted extraction (EAE)
Hydro distillation
Steam distillation
Common natural products‘ isolation methods
The Isolation of Natural Products: Morphine and Other Alkaloids - YouTube
Purification
▪ Liquid-liquid extraction
▪ Lyophilization
▪ Precipitation
▪ Crystallization
▪ Chromatographic techniques (TLC, CC, CCC, CPC, VLC, FC, HPLC, GC, …)
Liquid-liquid extraction
MeOH:H2O
(80:20)
Hexan
MeOH:H2O
(20:80)
CHCl3 H2O
EtOAc H2O
Chromatographic techniques
HPLC detectors
▪ UV detector
▪ DAD
▪ Fluorescence detector
▪ Electrochemical detector
▪ Refractive index detector
▪ ELSD
▪ MS
ELSD
Identification methods
▪ UV/Vis spectrophotometry
▪ Infrared spectroscopy (IR)
▪ Mass spectrometry (MS)
▪ Nuclear magnetic resonance (NMR)
▪ X-ray diffraction
▪ Chiroptical methods:
• Optical rotation (OR)
• Electronic circular dichroism (ECD)
• Vibrational circular dichroism (VCD)
Hyphenated techniques
Study literature
▪ Natural products isolation : methods and protocols. Edited by Satyajit D. Sarker - Lutfun Nahar. Third edition. New York:
Humana Press, 2012. xii, 552. ISBN 9781617796234.
▪ Green extraction of natural products : theory and practice. Edited by Farid Chemat - Jochen Strube. Weinheim: Wiley-VCH,
2015. xviii, 363. ISBN 9783527336531.
▪ BART, Hans‐Jörg. Extraction of natural products from plants–An introduction. Industrial scale natural products extraction,
2011, 1-25.
▪ BUCAR, Franz; WUBE, Abraham; SCHMID, Martin. Natural product isolation–how to get from biological material to pure
compounds. Natural product reports, 2013, 30.4: 525-545.
▪ CHEMAT, Farid, et al. Ultrasound assisted extraction of food and natural products. Mechanisms, techniques, combinations,
protocols and applications. A review. Ultrasonics sonochemistry, 2017, 34: 540-560.
▪ ZHANG, Qing-Wen; LIN, Li-Gen; YE, Wen-Cai. Techniques for extraction and isolation of natural products: A comprehensive
review. Chinese medicine, 2018, 13.1: 1-26.
▪ ABDELMOHSEN, UR; SAYED, AM; ELMAIDOMY, AH. Natural Products’ Extraction and Isolation-Between Conventional and
Modern Techniques. Frontiers in Natural Products, 2022, 1:873808.