Chemical derivatization strategies for enhancing the HPLC analytical performance of natural active triterpenoids

Triterpenoids widely exist in nature,displaying a variety of pharmacological activities.Determining triterpenoids in different matrices,especially in biological samples holds great significance.High-performance liquid chromatography(HPLC)has become the predominant method for triterpenoids analysis due to its exceptional analytical performance.However,due to the structural similarities among botanical samples,achieving effective separation of each triterpenoid proves challenging,necessitating significant improvements in analytical methods.Additionally,triterpenoids are characterized by a lack of ultraviolet(UV)absorption groups and chromophores,along with low ionization efficiency in mass spectrometry.Consequently,routine HPLC analysis suffers from poor sensitivity.Chemical derivatization emerges as an indispensable technique in HPLC analysis to enhance its performance.Considering the structural characteristics of triterpenoids,various derivatization reagents such as acid chlorides,rhodamines,isocyanates,sulfonic esters,and amines have been employed for the derivatization analysis of triterpenoids.This review comprehensively summarized the research progress made in derivatization strategies for HPLC detection of triterpenoids.Moreover,the limitations and challenges encountered in previous studies are discussed,and future research directions are proposed to develop more effective derivatization methods.

Steroids, Tri- and Meroterpenoids with a Quinone Structure—A Review

Terpenoids with quinoid structures are found as natural products. This includes steroidal quinones, quinones with a secosteroid structure and meroterpenoid quinones. Importantly, catechol estrogens as endogenous metabolites of estradiol and estrone are precursors of reactive quinones and semiquinones, which are thought to contribute to estrogen-induced carcinogenesis. On the other hand, a number of quinones that include substituted naphthoquinones and anthraquinones are highly cytotoxic and have been used in cancer treatment. This makes the structures interesting synthetic targets. The following is a review of important natural and synthetic terpenoid and steroid quinone hybrids.

Antioxidant,antimicrobial,and α-glucosidase inhibitory activities of saponin extracts from walnut(Juglans regia L.) leaves

Objective:To investigate the relationship between triterpenoid saponin content and antioxidant,antimicrobial,and α-glucosidase inhibitory activities of 70%ethanolic,butanolic,aqueous,supernate and precipitate extracts of Juglans regia leaves.Methods:Triterpenoid saponins of different Juglans regia leaf extracts were measured by the vanillin method.Antioxidant activity was evaluated against DPPH and ABTS free radicals.We also assessed α-glucosidase inhibitory and antimicrobial activities of the leaf extracts.Pearson’s correlation coefficient was evaluated to determine the correlation between the saponin content and biological activities.Results:The butanolic extract was most effective against DPPH with an IC50of 6.63μg/mL,while the aqueous extract showed the highest scavenging activity against ABTS free radical with an IC50of 42.27μg/mL.Pearson’s correlation analysis indicated a strong negative correlation (r=-0.956) between DPPH radical scavenging activity (IC50) and the saponin content in the samples examined.In addition,the aqueous extract showed the best α-glucosidase inhibitory activity compared with other extracts.All the extracts had fair antibacterial activity against Bacillus subtilis,Escherichia coli,and Klebsiella pneumoniae except for the aqueous extract.Conclusions:Juglans regia extracts show potent antioxidant,antimicrobial,and α-glucosidase inhibitory activities.There is a correlation between saponin levels in Juglans regia leaf extracts and the studied activities.However,additional research is required to establish these relationships by identifying the specific saponin molecules responsible for these activities and elucidating their mechanisms of action.

Four new lanostane triterpenoids featuring extendedπ-conjugated systems from the stems of Kadsura coccinea

Four new 14(13→12)-abeolanostane triterpenoids featuring extendedπ-conjugated systems,kadcoccitanes E-H(1-4),were obtained from the stems of Kadsura coccinea through using a HPLC−UV-guided approach.Their structural and configurational determination was accomplished through extensive spectroscopic analysis coupled with quantum chemical calculations.Kadcoccitanes E-H were tested for their cytotoxic activities against five human tumor cell lines(HL-60,A-549,SMMC-7721,MDA-MB-231,SW-480)but none of them exhibited activities at the concentration 40μM.

Bitter Bottle Gourd Toxicity

Bottle gourd (Lagenaria siceraria), colloquially known as “lauki” or “doodhi” in India, is an edible plant in the Cucurbitaceae family. Consumption of raw bottle gourd juice is common practice in India. However, little known is the fact that ingestion of raw bottle gourd juice that is extremely bitter tasting is associated with cucurbitacin toxicity. Cucurbitacin is a pheromone produced by the plant as a defense mechanism against insects and herbivores. It is responsible for imparting the bitter taste, and the associated toxicity. The exact mechanism of cucurbitacin toxicity is not well understood, however it is suspected to result in gastric erosions and increased capillary permeability, resulting in rapid onset of vomiting, diarrhea, gastrointestinal bleeding, hypotension and shock. As serum and urine concentration measurements of cucurbitacin are not readily available, bottle gourd toxicity remains a clinical diagnosis based largely on the temporal association of ingestion of unusually bitter tasting vegetable or its juice with rapid onset of symptoms. Physician awareness is therefore of paramount importance in the diagnosis of this unusual entity. We present the case of a 78-year-old woman, with no comorbid conditions, who presented to the Emergency Department (ED) with three episodes of vomiting and multiple episodes of watery loose stools soon after ingestion of extremely bitter tasting, fresh bottle gourd juice. A prompt diagnosis of cucurbitacin toxicity was made in the ED and fluid resuscitation was commenced expeditiously. However, it was noted that most physicians were unfamiliar with this entity, and therefore skeptical of the diagnosis. Our rationale in presenting this clinical case report is three-fold: 1) To create physician awareness regarding this unique clinical entity, especially among emergency physicians, as they are the first point of contact for a critically ill patient. 2) To highlight the rapid onset and progression of symptoms in cucurbitacin toxicity. 3) To emphasize aggressive fluid resuscitation and symptomatic management as the mainstay of clinical treatment.

Triterpenoids from the Dai Medicinal Plant Winchia calophylla

A new compound (1) named as winchic acid and eight known ones were isolated from the stem barks of Winchia colophylla A. DC. (collected in Xishuangbanna, Yunnan Province of China). The new compound 1 was identified as 3beta-hydroxy-27-(4-hydroxy-3-methoxy-E-cinnamoyloxy)-lup-20(29)-en-28-oic acid on the basis of 1D and 2D NMR experiments. The eight known compounds were determined to be lupenone, lupenyl acetate, betulinic acid, alpha-amyrin acetate, ursolic acid, ptiloepoxide, beta-amyrin and cycloeucalenol, respectively.

Two New Tirucallane-Type Triterpenoid Saponins from Sapindus mukorossi

Two new tirucallane-type triterpenoid saponins, Sapimukoside A (1) and Sapimukoside B (2), were isolated from the roots of Sapindus mukorossi Gaertn. On the basis of spectroscopic and chemical evidence, their structures were elucidated to be 3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-arabinopyranosyl-(1-->3)]-beta-D-glucopyranosyl-21, 23R-epoxyl tirucall-7, 24R-diene-3beta, 21-diol (1) and 3-O-alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranosyl-21, 23R-epoxyl tirucall-7, 24R-diene-3beta, 21-diol (2).

A New Triterpenoid Saponin from Rhaponticum uniflorum (Compositae)

A new triterpenoid saponin, namely unifloroside, together with five known compounds, was isolated from Rhaponticum uniflorum (L.) DC. The structure of the new triterpenoid saponin was elucidated as 3_O_ α_L_arabinopyranosyl_urs_9(11),12_dien_28_oic acid β_D_glucopyranosyl ester mainly by using 1D, 2D_NMR techniques and chemical methods.

Triterpenoids from Rubus buergeri

A new triterpenoid, methyl buergericate (12a), which was elucidated as 2 alpha, 3 alpha, 19 alpha, 24-tetrahydroxyl olean-12-en-28-oic acid methyl ester by spectroscopic methods, together with eleven known triterpenoids was isolated from Rubus buergeri Miq. The isolation of the above chemical constituents from this plant was reported for the first time.

Isolation and Identification of Ecliptasaponin A andEcliptasaponin B from Eclipta alba(L.)Hassk

Two new triterpenoid glucosides ecliptasaponin A(3)and ecliptasaponin B(4)were isolated together with echinocystic acid(1)and oleanolic acid(2)from Eclipta alba(L.) Hassk.Their structures were deduced as 3β,16a-dihydroxy olean-12-ene-28-oic acid-3β-O-β-D-glu-copyranoside(3)and 3β-O-[β-D-glucopyranosyl(1-4)]-β-D-glucopyranosyl-16a-hydroxy olean-12-ene-28-oic acid 28-O-β-D-glucopyranoside(4),based on spectral analysis and chemical evidences as well as results ofhydrolysis.

Studies on Triterpenoid Saponins of Seeds of Aesculus chinensis Bunge var. chekiangensis (Hu et Fang) Fang

Aim To study the saponin constituents of the seeds of Aesculus chinensis Bunge var. chekiangensis (Hu et Fang) Fang. Methods Compounds were separated and purified by macroreticular resin column chromatography and high-performance liquid chromatography. Their structures were elucidated by spectroscopic and hydrolysis analysis. Results Six compounds were isolated from the 70% ethanolic extracts. They were identified as escins IVc, IVd, Ia, Ib, isoescins Ia and Ib, respectively. Conclusion The above compounds were obtained from the seeds of Aesculus chinensis Bunge var.chekiangensis (Hu et Fang) Fang for the first time.

A NEW BACCHARANE-TYPE TRITERPENOID ISOLATED FROM THE ROOTS OF SAUSSUREA LAPPA C.B.CLARKE

A new baccharane-type triterpene, 3-acetoxy-9(11)-baccharene(1),as well as a known compound, a-amyrin(2), has been isolated from the ether extract of the roots of Saussurea lappa C. B. Clarke. The structure of the new compound was identified by spectrum analysis.

Effects of Different Decolorants on Retention Rate of Total Triterpenes in Fruit and Rattan Stems of Schisandra chinensis(Turcz.) Baill

This study was to investigate the decoloration effects of activated clay, activated carbon, diatomite, Ca group bentonite, kaolin, activated aluminum oxide, magnesium oxide and attapulgite. Ultraviolet-visible spectroscopywas adopted to de- tect the absorbanees of the extracts of Schisandra chinensis fruit and rattan stems, the contents of total triterpenoids in S. chinensis fruit and rattan stems were deter- mined, and the decoloration rate and the retention rate of total triterpenoids of S. chi- nensis fruit and rattan stems were calculated. The results indicated that, attapulgite exhibited the best decoloration effect on the extract of S. chinensis fruit, with a de- coloration rate up to 60.47%, activated carbon exhibited a better decoloration effect on the extract of S. chinensis rattan stems, with a decoloration rate up to 69.24%, and they had relatively higher retention rates of total triterpenoids. In the eight de- colorants, attapulgite showed the best decoloration effect on the extract of S. chi- nensis fruit, and activated carbon exhibited the best decoloration effect on the ex- tract of S. chinensisrattan stems.

Triterpenoids from the Fruiting Body of Ganoderma lucidum

A new triterpenoid, named ganolactone, was isolated from the CH 2Cl 2 soluble fraction of the fruiting body of Ganoderma lucidum. Its structure was deduced as 7β hydroxy 3,11,15 trioxo lanosta 8 en 24→20s lactone (1) on the basis of spectral analysis (UV, IR, MS. 1H NMR, 13 C NMR and 2D NMR) and was confirmed by X ray diffraction. In addition, three known compounds, ganoderiol A (2), ganoderiol B (3) and ganodermatriol (4), were obtained.

New Triterpenoid Saponins from Polycarpon prostratum (Caryophyllaceae)

Three new triterpenoid saponins, namely prostratosides A-C (1-3), were isolated from the whole plant of Polycarpon prostratum (Forssk.) Aschers. et Schwein. ex Aschers. By spectroscopic methods, their structures were determined as 3_O_{β_D_xylopyranosyl_(1→2)_β_D_glucopyranosyl_(1→4)_[β_D_glucopyranosyl_(1→2)]_α_L_arabinopyranoside}_22α_acetoxy_saikogenin G, 3_O_{β_D_xylopyranosyl_(1→2)_β_D_glucopyranosyl_(1→4)_[β_D_glucopyranosyl_(1→2)]_α_L_arabinopyranoside}_16α_hydroxy_22α_acetoxy_saikogenin E and 3_O_{β_D_xylopyranosyl_(1→2)_β_D_glucopyranosyl_(1→4)_[β_D_glucopyranosyl_(1→2)]_α_L_arabinopyranoside}_21β_acetoxy_saikogenin G, respectively.

Determination of ganoderic acids in rat plasma after oral administration of total triterpenoids from Ganoderma lucidum

To investigate the absorption of total triterpenoids from Ganoderma lucidum in rats. HPLC-DAD and LC-MS methods were used to identify ganoderic acids in rat plasma after oral administration of total triterpenoids from G. lucidum by comparing their HPLC retention behaviors, UV absorption spectra, and mass spectra with authentic samples. Five ganoderic acids, ganoderic acid C2, C6, G, B and A were simultaneously detected in rat plasma. Ganoderic acids can be directly absorbed into circulation after oral administration of total triterpenoids from G. lucidum in rats.

Chemical Constituents of Pomatosace filicula

A new triterpenoid saponin, namely pomatoside A (3) 13beta, 28-epoxy-16-oleananone-3-O-[alpha-L-rhamnopyranosyl-(1 -->6)-O-beta-D-glucopyranosyl-(1 -->4)-O-beta-D-glucopyranosyl-(1 -->6)-O-beta-D-glucopyranosyl-(1 -->2)]-beta-D-glucopyranoside, together with twelve known compounds, was isolated for the first time from Pomatosace filicula Maxim., a monotypic endemic plant, grown in the Qinghai-Xizang Plateau of China. Their structures were elucidated by spectroscopic analyses and chemical methods, especially 2D-NMR.

Adjuvant effects of saponins on animal immune responses

Vaccines require optimal adjuvants including immunopotentiator and delivery systems to offer long term protection from infectious diseases in animals and man. Initially it was believed that adjuvants are responsible for promoting strong and sustainable antibody responses. Now it has been shown that adjuvants influence the isotype and avidity of antibody and also affect the properties of cell-mediated immunity. Mostly oil emulsions, lipopolysaccharides, polymers, saponins, liposomes, cytokines, ISCOMs (immunostimulating complexes), Freund’s complete adjuvant, Freund’s incomplete adjuvant, alums, bacterial toxins etc., are common adjuvants under investigation. Saponin based adjuvants have the ability to stimulate the cell mediated immune system as well as to enhance antibody production and have the advantage that only a low dose is needed for adjuvant activity. In the present study the importance of adjuvants, their role and the effect of saponin in immune system is reviewed.

Advances in Research on Triterpenoids and Volatile Compositions of Kudingcha

Kudingcha, a commonly used traditional Chinese medicine, has multiple functions in anti-radiation, anti-aging, quickening the blood vessels, reducing blood lipid and blood pressure and so forth. Therefore, this article reviews the origins of Kudingcha, and analyzes the major triterpenoids and volatile chemicals, with an at- tempt to provide more references for the development and utilization of Kudingcha.

Two New Lanostane-type Triterpenoids from Mulgedium tataricum

Two new triterpenoids, lanost-9（11）, 23Z（24）-dicnc-3β, 25-diol （1） and lanost-9（11）, 25- diene-3β, 24-diol （2） were isolated from Mulgedium tataricum L. Their structures wcrc elucidated by spectral methods.