Citrus fruit with glowing flavonoids extracted by a green solvent.

Citrus Power: Unlocking Flavonoids with Green Solvents

Soraya Malik in Health & Wellness August 2025 • 4 min read.

"A natural way to boost the extraction of antioxidants from Aurantii Fructus for health and wellness."

In a world increasingly focused on sustainable solutions, the quest for eco-friendly extraction methods has never been more critical. Conventional solvents often used to extract bioactive compounds from natural sources can be harmful and pose disposal challenges. Deep eutectic solvents (DESs) have emerged as promising "green" alternatives, attracting significant attention due to their unique physical and chemical properties.

DESs are created by mixing two or more safe components—a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA)—that combine to form a eutectic mixture. This mixture is characterized by strong intermolecular hydrogen bonds. Commonly used HBAs include choline chloride and betaine hydrochloride, both inexpensive, biodegradable, and non-toxic. When mixed with HBDs like urea, ethylene glycol, or glycerol, they create solvents with remarkable advantages.

Aurantii Fructus (AF), the fruit of Citrus aurantium L., has been used in traditional Chinese medicine for centuries to treat gastrointestinal disorders. Its active components, including narirutin, naringin, hesperidin, and neohesperidin, possess anticarcinogenic, antioxidant, and antimicrobial effects. While traditional extraction methods involve hazardous solvents, DESs offer a safer, more sustainable approach. This article explores how DESs can enhance the extraction of these valuable flavonoids from AF, opening new avenues for natural health and wellness.

The Science Behind Deep Eutectic Solvents

Citrus fruit with glowing flavonoids extracted by a green solvent.

Deep eutectic solvents (DESs) are gaining traction as environmentally friendly alternatives to traditional organic solvents. These solvents are typically composed of a hydrogen bond acceptor (HBA) and a hydrogen bond donor (HBD), which, when mixed, form a eutectic mixture with a melting point lower than that of the individual components.

One of the most appealing aspects of DESs is their tunability. By carefully selecting the HBA and HBD, scientists can tailor the solvent's properties to optimize the extraction of specific compounds. In the case of Aurantii Fructus (AF), researchers have found that betaine/ethanediol is particularly effective for extracting key flavonoids like narirutin, naringin, hesperidin, and neohesperidin.

Here are some benefits:

Eco-Friendly: DESs are made from biodegradable and non-toxic components.
Cost-Effective: The starting materials for DESs are typically inexpensive.
Easy to Prepare: DESs can be easily synthesized with minimal equipment.
Tunable Properties: By adjusting the HBA and HBD, the solvent can be optimized for specific extraction needs.

To maximize the extraction yield, several factors must be carefully considered. These include the ratio of HBA to HBD, the water content in the DES, the extraction temperature, the solid-to-liquid ratio, and the extraction time. By optimizing these parameters, researchers can achieve higher yields of the target compounds.

A Promising Future for Green Extraction

The findings of this study highlight the potential of DESs as promising green solvents for extracting bioactive ingredients from traditional Chinese medicine. Compared to traditional solvents like methanol, DESs offer higher extraction yields and reduced environmental impact. As the demand for natural health products continues to grow, DESs may play a crucial role in developing sustainable extraction methods that preserve the potency and purity of valuable plant compounds.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1002/pca.2801, Alternate LINK

Title: Deep Eutectic Solvent As A Green Solvent For Enhanced Extraction Of Narirutin, Naringin, Hesperidin And Neohesperidin From Aurantii Fructus

Subject: Complementary and alternative medicine

Journal: Phytochemical Analysis

Publisher: Wiley

Authors: Yongjing Liu, Hua Zhang, Hongmin Yu, Suhua Guo, Dawei Chen

Published: 2018-11-13

Everything You Need To Know

What are deep eutectic solvents (DESs)?

Deep eutectic solvents (DESs) are environmentally friendly alternatives to traditional organic solvents. They are created by mixing a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA), which form a eutectic mixture. This mixture has a melting point lower than that of its individual components, making it useful for dissolving and extracting substances like flavonoids.

Why is Aurantii Fructus important?

Aurantii Fructus (AF), the fruit of Citrus aurantium L., is important because it contains valuable flavonoids such as narirutin, naringin, hesperidin, and neohesperidin. These compounds possess beneficial properties, including anticarcinogenic, antioxidant, and antimicrobial effects. Extracting these flavonoids effectively and safely is key to unlocking their health benefits for various applications in natural health and wellness.

What is the significance of deep eutectic solvents (DESs)?

The significance of deep eutectic solvents (DESs) lies in their ability to extract flavonoids from Aurantii Fructus more efficiently and in an environmentally friendly way. Unlike conventional solvents, DESs are biodegradable, non-toxic, and made from inexpensive components. Their tunability allows scientists to tailor the solvent's properties, such as selecting betaine/ethanediol for optimal extraction of specific flavonoids from Aurantii Fructus, leading to a greener and more sustainable approach to obtaining these valuable compounds.

What are the key components of deep eutectic solvents (DESs)?

Key components of deep eutectic solvents (DESs) are the hydrogen bond acceptor (HBA) and the hydrogen bond donor (HBD). Common HBAs include choline chloride and betaine hydrochloride, while HBDs can be urea, ethylene glycol, or glycerol. The specific combination of HBA and HBD determines the properties of the DES, allowing for customized extraction capabilities. These components are mixed to form a eutectic mixture that's effective at extracting desired compounds like the flavonoids found in Aurantii Fructus.

How can extraction with deep eutectic solvents (DESs) be optimized?

Optimizing extraction with deep eutectic solvents (DESs) involves considering several factors to maximize yield. These factors include the ratio of the hydrogen bond acceptor (HBA) to the hydrogen bond donor (HBD), the water content in the DES, the extraction temperature, the solid-to-liquid ratio, and the extraction time. Careful control of these parameters is essential for achieving higher yields of target compounds like narirutin, naringin, hesperidin, and neohesperidin from Aurantii Fructus, thereby enhancing the effectiveness of the extraction process.