Anti-inflammatory Principles from the Stem and Root Barks of Citrus medica

Abstract

Bioassay-guided investigation of the anti-inflammatory principles from the stem and root barks of Citrus medica L. var. sarcodactylis SWINGLE has led to the isolation of a new coumarin, namely citrumedin-B (1) and thirty known compounds. The anti-inflammatory components were xanthyletin (2), nordentatin (3), atalantoflavon (4) and lonchocarpol A (5) which displayed potent nitric oxide (NO)-reducing activity in microglial cells. The structure of this new compound was completely elucidated using a combination of 2D NMR techniques (correlation spectroscopy (COSY), nuclear Overhauser effect spectroscopy (NOESY), heteronuclear multiple quantum coherence (HMQC) and heteronuclear multiple bond connectivity (HMBC)) and HR-electrospray ionization (ESI)-MS analyses. The known compounds were identified by comparison of their spectroscopic and physical data with those reported in the literature. These results can be inferred from the treatment of allergic response and inflammatory properties of Citrus medica L. var. sarcodactylis SWINGLE in traditional Chinese medicine.

Phytochemical analysis and evaluation antibacterial activity of Citrus medica peel and juice growing in Kurdistan/Iraq

“…Results of qualitative phytochemical screening in (table 1) clearly demonstrated the presence of number important active constituents. Presence of carbohydrates, flavonoids, phenols, steroids and absence of saponins, anthraquinones, coumarin in Citrus medica in agreement with previously recorded data (Kabra et al, 2012;Chan et al, 2010), while presence of tannins, cardioactive glycosides in peel and juice and absence of alkaloids in peel of Iraqi species in contrast to the same study (Kabra et al, 2012) . The quantitative determination of plant bioactive constituents in this study the results showed in (table 2) revealed that phenolic content (21.18 & 9.38 mg/g dry extract) in Citrus medica was higher than flavonoid content (4.59& 1.44 mg/g dry extract) in peel and juice respectively are in accordance with those carried out in Riyadh, Saudi Arabia in which Citrus medica fruits showed high total phenol content (192.4 mg GA /100 g) than flavonoid values (74.1 mg quercetin /100 g) (Al-Yahya et al, 2013).…”

The Chemistry and Pharmacology of Citrus Limonoids

“…When 1 was discovered [114], its bitter taste and some preliminary assays disguised it as an alkaloid probably suggesting to Berlays [115] the stem-in(e) which was commonly used for quinine-like compounds. Limonin has also recently been found in Citrus genus plant bark [25,116,117], and root [118], tissues. In addition to the above reported plants, 1 has been isolated from numerous non-Citrus species such as the endemic Brazilian species Raulinoa echinata [119], Glycosmis parva (a wild small shrub distributed in Thailand) [120], Poncirus trifoliata (a tree that is widely distributed in China) [121], and Dictamnus angustifolius [27,122,123].…”

“…In the last decade, delayed bitterness has continued to attract interest from several research groups and a number of papers have been dedicated to studies on mechanisms underlying delayed bitterness [10][11][12][13][14], possible ways of reducing [15][16][17][18] or modulating [19][20][21][22][23] the formation of bitter limonoids [1] in citrus fruits and juice products. On the other hand, evaluation of biological activities of CLs have disclosed great potential for these phytochemicals that furnished the rational basis of traditional medicinal uses of CL-containing folk remedies [24][25][26][27][28][29] as well as modern nutraceutical products [29,30]. Obviously, taste is a biological answer to xenobiotics just like any other pharmacological effect and during studies on delayed bitterness, a new limonoid possibly endowed with peculiar biological activities was discovered (see Section 3).…”

“…The unbalanced solubility profile of the latter may explain the relatively low number of studies on their respective biological activities which are hampered by difficult isolation from natural sources and poor pharmacokinetics. Analgesic [45], anticancer [46][47][48][49][50][51][52][53][54][55][56][57][58][59], anti-inflammatory [45,[60][61][62], antibacterial [63,64], antioxidant [4,65,66], antiviral [67], larvicidal [68,69] Anticancer [46,47,58,59,70], anti-hyperglycemic [71], anti-inflammatory [25,62], antioxidant [4,65,66], antiviral [67], larvicidal [68,69] …”

“…SQ is oxidized to give a reactive epoxide, (S)-2,3-oxidosqualene (also named 2,3-epoxysqualene or squalene epoxide, 23), which undergoes cyclization generating a prolanosterol cation 24. Through a series of 1,2-shifts of hydrides and methyls, this intermediate may generate several triterpenes including lanosterol (25) and the two epimers euphol (26) and tirucallol (27). The latter lanostadienols are both considered as the ultimate biogenetic precursors of CLs.…”