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Six diterpenoids including three ent-kauranes (1-2, 4) and three cleistanthanes (3, 5-6) were isolated from the roots and stems of Phyllanthus acidus (L.) Skeels. Of them, (16S)-ent-16,17,18-tri-hydroxy-19-nor-kaur-4-en-3-one (1), phyllanthone A (2), and 6-hydroxycleistanthol (3) are new compounds, while the ent-kaurane diterpenoids were reported from the titled plant for the first time. Their structures were elucidated on the basis of the extensive spectroscopic analyses. Compounds 2 and 4-6 displayed cytotoxic potential with IC 50 values ranging from 1.96 to 29.15 μM. They also showed moderate anti-inflammatory activities (IC 50  = 6.30-12.05 μM). Particularly, the new ent-kaurane 2 displayed cytotoxic potential against HL-60 (IC 50  = 2.00 μM) and MCF-7 (IC 50  = 3.55 μM) cells, and anti-inflammatory activity (IC 50  = 6.47 μM)., (Copyright © 2022. Published by Elsevier B.V.)

The young leaves of Phyllanthus acidus (Euphorbiaceae) are commonly used as edible vegetables in Indonesia, Thailand, and India, and their water infusions as dieting aids for people trying to remain slim. However, it is regarded as a poisonous plant in Malaya, and current researches are insufficient to provide a conclusion on its toxicity and safety under large doses. In this study, we firstly found that the refined nonpolar extracts of P. acidus leaves showed significant cytotoxic effect against BEAS-2B and L02 normal cell lines with IC 50 values of 2.15 and 1.64 mg/mL, respectively. Further bioactivity-guided isolation produced four new rare dichapetalins (pacidusins A-D) from the most active fraction. Their structures including absolute configurations were elucidated by extensive spectroscopic data and X-ray diffraction analysis. All the isolated dichapetalins exhibited moderate cytotoxicity against, BEAS-2B and L02 normal cell lines with IC 50 values ranging from 12.44 to 22.55 μM, as well as five human cancer cell lines with IC 50 values ranging from 3.38 to 22.38 μM. Furthermore, the content of the main dichapetalins in the leaves were determined by analytical HPLC, which showed that the leaves contained a very high amount of the four isolated dichapetalins with a total yield of 0.488 mg/g of dry plant material. These toxic dichapetalins may lead to adverse health effects in higher doses. Our findings indicate that the dichapetalin containing leaves may not be suitable for consumption in large quantities as food, but demonstrate their potency as anti-cancer agents for new drug discovery., (Copyright © 2021. Published by Elsevier Inc.)

Ethnopharmacological Relevance: Terminalia chebula (TC), a well-known Indian Ayurvedic medicine introduced into China in the Sui and Tang Dynasties, has been recorded and used medicinally as Fructus Chebulae, together with its variety tomentella (TCT) in the Chinese Pharmacopoeia. They have been also used commonly for the treatment of diabetes mellitus by Tibetan medicine., Aim of the Study: To investigate the main bioactive and therapeutic principles in the fruits of TCT, based on the extensive evaluation of their anti-inflammatory and hypoglycemic activities., Materials and Methods: The TCT fresh fruits were analyzed by HPLC and separated further by column chromatography and preparative HPLC. The isolated compounds were identified by extensive spectroscopic analyses, including 1D/2D NMR, MS, UV, IR and ECD. Anti-inflammatory activity was evaluated by inhibition of NO production in RAW264.7 cells. The specific iNOS (PDB ID: 3E7G) structure was prepared by Discovery Studio 4.0, and the molecular docking simulation was performed on GOLD (version 5.2.2). Hypoglycemic activity was measured using the substrate solution of 4-nitrophenyl-α-d-glucopyranoside enzyme and buffer solution., Results: The HPLC analysis method of polyphenols in the fruits of TCT was established, and 13 main chromatographic peaks were identified, including six hydrolyzable tannins (2, 4-7, 10-11), three simple phenols (12-14), and one oleanane pentacyclic triterpene, arjungenin. Extensive chromatographic separation of TCT fresh fruits yielded 14 compounds, including one new natural hydrolyzable tannin, 2,3-(S)-HHDP-6-O-galloyl-d-glucose (1). The known compounds were identified as 10 hydrolyzable tannins (2-11) and three simple phenols (12-14). Compounds 10 (IC 50  = 36.43 ± 0.21 μM), 11 (IC 50  = 42.28 ± 0.09 μM) displayed stronger NO inhibitory activity than the positive control L-NMMA (IC 50  = 42.34 ± 0.66 μM), while 2, 4, and 9 showed moderate inhibitory activity against NO production. Further molecular docking simulation of specific iNOS on 10 and 11, as well as five previously isolated lignans 15-19 showed that there were no obvious rules between docking results and the in vitro NO inhibitory activity for hydrolyzable tannins (10 and 11), while the mechanism of anti-inflammatory activity for lignans was related to the substitution of conjugated aldehyde groups. Moreover, most of the hydrolyzable tannins (1-2, 4-5, 9-11) and simple phenol (12) displayed stronger inhibitory effects on α-glucosidase than the positive control, quercetin (IC 50  = 6.118 ± 0.071 μM), with IC 50 values ranging from 0.079 to 16.494 μM. Among these bioactive isolates, the hydrolyzable tannins 2, 4-5, and 9-11, and simple phenol 12 are major chemical components in TCT fruit., Conclusions: The results showed that lignans and hydrolyzed tannins are the main active ingredients of TCT fruits, responsible for the traditional treatment of sore throat and cough. Moreover, hydrolyzed tannins and simple phenolic compounds with potential hypoglycemic activity are closely related to the ethno-pharmacological uses of TCT fruits on diabetes in Tibetan medicine., (Copyright © 2021 Elsevier B.V. All rights reserved.)

As a subgroup of flavoalkaloids, N -ethyl-2-pyrrolidinone substituted flavan-3-ols are reported to possess various biological activities that may play important roles in the beneficial healthcare functions of tea. The HPLC and LC-MS analyses showed the existence of N -ethyl-2-pyrrolidinone substituted flavan-3-ols in 'Jin-Ya', which is a Yunnan black tea produced only from the buds of the tea plant Camellia sinensis var. assamica . Further phytochemical study on this precious black tea led to the identification of 8 flavoalkaloids, 1 - 8 , along with 11 known flavan-3-ols ( 9 - 14 ) and flavonol glycosides ( 15 - 19 ). The new compounds, (-)-6-(5″ S )- N -ethyl-2-pyrrolidinone-epiafzelechin ( 1 ), (-)-8-(5″ R )- N -ethyl-2-pyrrolidinone-epiafzelechin-3- O -gallate ( 2a ), and (-)-8-(5″ S )- N -ethyl-2-pyrrolidinone-epiafzelechin-3- O -gallate ( 2b ), were identified based on extensive spectroscopic analysis. Flavoalkaloids 2 - 6 showed inhibitory activity on α-glucosidase with IC 50 values ranging from 2.09 to 8.47 μM, compared to those of quercetin and acarbose (IC 50 = 6.87 and 228.9 μM, respectively). Moreover, compounds 2 , 3 , and 6 displayed an inhibitory effect on acetyl-cholinesterase with IC 50 values of 14.23, 33.79, and 34.82 μM, respectively, compared to tacrine (IC 50 = 0.223 μM).

Camellia fangchengensis Liang et Zhong, belonging to the genus Camellia sect. Thea (Theaceae), is an endemic tea species to the south and southwest areas of Guangxi province, People's Republic of China. Known as a wild tea plant, the leaves have been used for producing green tea or black tea by the local people of its growing area. HPLC and LC-MS analysis showed the leaves contain oligomeric catechins as major phenolic components. Further detailed phytochemical study led to the identification of five flavan-3-ol dimers (1-5) including two new ones, fangchengbisflavans A (1) and B (2) from the leaves of C. fangchengensis, together with six known monomers (6-11) and one glucoside (12), in addition to gallic acid (13). Their structures were determined by extensive spectroscopic analysis. Most of the isolates displayed significant antioxidant activities in 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS + ) radical scavenging assays. The results suggested that the leaves of C. fangchengensis, rich in flavan-3-ol oligomers and monomers as potent antioxidants, could be a valuable plant resource for the production of tea and natural beverages.

Ethnopharmacological Relevance: Piper wallichii (Miq.) Hand.-Mazz. is a medicinal plant used widely for the treatment of rheumatoid arthritis, inflammatory diseases, cerebral infarction and angina in China. Previous study showed that lignans and neolignans from Piper spp. had potential inhibitory activities on platelet aggregation. In the present study, we investigated the chemical constituents of Piper wallichii and their antithrombotic activities, to support its traditional uses., Materials and Methods: The methanolic extract of the air-dried stems of Piper wallichii was separated and purified using various chromatographic methods, including semi-preparative HPLC. The chemical structures of the isolates were determined by detailed spectroscopic analysis, and acidic hydrolysis in case of the new glycoside 2. Determination of absolute configurations of the new compound 1 was facilitated by calculated electronic circular dichroism using time-dependent density-functional theory. All compounds were tested for their inhibitory effects on platelet aggregation induced by platelet activating factor (PAF) in rabbits׳ blood model, from which the active ones were further evaluated the in vivo antithrombotic activity in zebrafish model., Results: A new neolignan, piperwalliol A (1), and four new aromatic glycosides, piperwalliosides A-D (2-5) were isolated from the stems of Piper wallichii, along with 25 known compounds, including 13 lignans, six aromatic glycosides, two phenylpropyl aldehydes, and four biphenyls. Five known compounds (6-10) showed in vitro antiplatelet aggregation activities. Among them, (-)-syringaresinol (6) was the most active compound with an IC50 value of 0.52 mM. It is noted that in zebrafish model, the known lignan 6 showed good in vivo antithrombotic effect with a value of 37% at a concentration of 30 μM, compared with the positive control aspirin with the inhibitory value of 74% at a concentration of 125μM., Conclusion: This study demonstrated that lignans, phenylpropanoid and biphenyl found in Piper wallichii may be responsible for antithrombotic effect of the titled plant., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Ripe Pu-er tea, a special microbial postfermented tea originated from Yunnan Province, China, since ancient times, is made from green Pu-er tea prepared from the leaves of Camellia sinensis var. assamica (Theaceae). Chemical investigation on thearubigin (n-BuOH-soluble) fraction of the commercial ripe Pu-er tea, led to the identification of four new flavan-3-ol derivatives, 8-carboxymethyl-(+)-catechin (1), 8-carboxymethyl-(+)-catechin methyl ester (2), 6-carboxymethyl-(+)-catechin (3), and 6-carboxyl-(-)-gallocatechin (4), together with 18 known compounds, including other three flavan-3-ol derivatives (5-7), 10 flavonoid glycosides (8-17), two hydrolyzable tannins (18 and 19), two quinic acid derivatives (20-21), and a purine alkaloid (22). Flavonoid glycosides 8-11 are reported from tea plants for the first time. The thearubigin fraction of ripe Pu-er tea was qualitatively analyzed by HPLC, and gallic acid was found to be the major component. Compounds 4, 6-17, 21 and 22 were tested for their acute activities on insulin sensitivity in differentiated 3T3-L1 adipocytes, but none of them showed significant bioactivity at a concentration of 10 μM.

Pu-er ripe tea is a special microbial post-fermented tea made from Pu-er raw tea, a kind of green tea produced from the leaves of Camellia sinensis var. assamica. It is one of the most consumed teas in the past two decades in China, due to its special flavor, taste, and beneficial effects. This work aimed to obtain diverse catechin structures from Pu-er ripe tea, which led to the isolation of four new phenylpropanoid-substituted flavan-3-ols, puerins C-F (1-4), together with four known flavan-3-ols, (+)-catechin (5), (-)-epicatechin (6), (+/-)-gallocatechin (7), and (-)-epigallocatechin (8). Their structures were elucidated on the basis of detailed spectroscopic analysis, including 1D and 2D NMR, mass and CD spectra. Compounds 1-4, which could be formed in the post-fermentative process of Pu-er tea, were isolated for the first time from tea and Theaceae plant.

A new 6/6/5/6-fused limonoid, phyllanthoid A (1), possessing both 19/30 and 19/29 oxygen bridges was isolated from Phyllanthus cochinchinensis (Euphorbiaceae), together with a new related limonoid, phyllanthoid B (2). Their structures were determined by spectroscopic analysis and single-crystal X-ray diffraction in the case of 1. Compound 1 displayed moderate antifeedant against the generalist plant-feeding insect Spodoptera exigua and cytotoxicity against the MCF-7 cell line.

Phytochemical investigation on the nonpolar extracts of P. acidus leaves afforded three new cleistanthane diterpenoids, named phyllanacidins A–C (1 – 3), in addition to three known ones (4 – 6). Among them, compounds 2 and 3 represent the first examples of 17- nor cleistanthane diterpenoids. Their structures including absolute configurations were elucidated on the basis of extensive spectroscopic data and single crystal X-ray diffraction analysis. All the isolated cleistanthane diterpenoids were evaluated for their cytotoxic activities against five human cancer cell lines. Compounds 4 – 6 exhibited moderate cytotoxicity with IC 50 values ranging from 16.11 to 30.82 μM. Unlabelled Image • Three new cleistanthane diterpenoids (1 – 3) were isolated from Phyllanthus acidus. • Their structures were elucidated on the basis of spectroscopic analysis. • 2 and 3 represent the first examples of 17- nor cleistanthane diterpenoids. [ABSTRACT FROM AUTHOR]

Four new cleistanthane diterpenoids, phyllaciduloids A–D ( 1 – 4 ), were isolated from the roots and stems of Phyllanthus acidus (L.) Skeels (Phyllanthaceae). Their structures were elucidated on the basis of extensive spectroscopic analysis. Phyllaciduloids B–D ( 2 – 4 ) present in their structures with ether bond between C-7 and C-16, which were rarely reported. All the isolates were evaluated for their cytotoxic activities against five human cancer cell lines. [ABSTRACT FROM AUTHOR]

Nine new minor dehydrogenated and cleavaged dammarane-type triterpenoid saponins, namely notoginsenosides ST6-ST14 ( 1 – 9 ) were isolated from the steamed roots of Panax notoginseng , together with 14 known ones. Among them, 5–7 and 21–22 were protopanaxadiol type and the left 18 compounds, including 1–4 , 8–20 , and 23 were protopanaxatriol type saponins. Their structures were identified by extensive analysis of MS, 1D and 2D NMR spectra, and acidic hydrolysis. Resulted from the side chain cleavage, the new saponins 1 and 2 featured in a ketone group at C-25, and 3–5 had an aldehyde unit at C-23. The known saponins 12 , 16 and 18 displayed the enhancing potential of neurite outgrowth of NGF-mediated PC12 cells at a concentration of 10 μM, while 20 exhibited acetyl cholinesterase inhibitory activity, with IC 50 value of 13.97 μM. [ABSTRACT FROM AUTHOR]