**1. Introduction**

Medicinal plants are getting more demand because of their distinctive features as an abundant source of curative phytochemicals that may be used to develop new medications. Approximately 20% of all known plants have been employed in pharmacological investigations, positively improving the healthcare system by treating cancer and other ailments [1]. Many of these medicinal plants are good sources of phytochemicals like polyphenols, carotenoids, flavonoids, anthocyanins, and vitamins that possess antioxidant activities. Today, medicinal plants are finding diverse use in society from medicine to cosmetics, nutraceuticals, herbal drinks,

herbal foods, and other articles in their daily uses. Plant phytoconstituents are created as secondary metabolites, which are produced through a variety of biological routes in secondary metabolism. The choice of solvents for extracting phytoconstituents from plants is critical. A suitable solvent has an appropriate extraction capacity as well as the ability to maintain the chemical structure of the desired molecules stable [2].

Green technologies are increasingly being employed in practically every scientific sector to promote ecologically acceptable activities that do little or no harm to humans. Ionic liquids, aqueous biphasic systems, and pressurized hot water have all become attractive research topics in recent years [3]. Traditional techniques of extracting phytoconstituents require the use of more powerful and toxic solvents (nonenvironmentally friendly), as well as more energy. Each method's extraction time varies, ranging from minutes to 7 days in the case of maceration [4]. Another problem is that none of the current plant processing methods meets all the economical, safety, and scalability requirements. Other concerns include security hazards, solvent toxicity, and the existence of solvent remnants in the extracts. The high cost of feedstock, the high cost of extracting desirable bioactive compounds, their comparatively low yield, and the resulting substantial concentration of residual waste biomass are the major roadblocks to commercially viable phytochemical production [5]. In many process sectors, microwave-assisted extractions like ultrasound-assisted extraction, pulsed electric field extraction, and molecular distillation have been reported. Green chemistry, as ecological and economic chemistry, could be one of the solutions to humanity's future [6]. The entire process of green extraction of phytoconstituents from natural sources is concluded in the **Figure 1**.

#### **Figure 1.**

*Extraction of crude drugs using green solvent, green extraction process, and purification techniques.*
