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Camellia taliensis (W. W. Smith) Melchior, belonging to the genus Camellia sect. Thea., is mainly distributed from northern Myanmar to western and southwestern Yunnan province of China, and its leaves have been used to make various teas by the locals of its growing regions. The chemical constituents of C. taliensis are significantly related to those of cultivated tea plants, C. sinensis and C. sinensis var. assamica. The HPLC-ESI-MS analysis of black tea prepared from the leaves of C. taliensis showed a rich existence of polyphenols. Further comprehensive chemical study led to the separation and recognition of 32 compounds (1–32), including one new hydrolyzable tannin, 1-O-galloyl-4,6-tetrahydroxydibenzofurandicarboxyl-β-D-glucopyranose (1), and one new natural product (24). The known compounds referred to seven hydrolyzable tannins (2–8), 10 flavonols and glycosides (9–18), and 14 simple phenolics (19–32). Their structures were elucidated by comprehensive spectroscopic analyses. Among them, 20 compounds (2, 3, 6, 7, 8, 15, 17, 18, 20–22, 24–32) were isolated from black tea for the first time. Most isolates displayed obvious antioxidant activities on DPPH and ABTS+ assays, and the hydrolyzable tannins 1, 3–5, 7, and 8 exhibited stronger inhibitory activities on α-glycosidase than quercetin and acarbose (IC50 = 5.75 and 223.30 μM, respectively), with IC50 values ranging from 0.67 to 2.01 μM. [ABSTRACT FROM AUTHOR]

A novel highly oxygenated norbisabolane sesquiterpene, namely phyllanthacidoid U (1), along with nine known sesquiterpenes (2–10) was isolated from the roots and stems of Phyllanthus acidus (L.) Skeels (Phyllanthaceae), collected from Xishuangbanna, Yunnan province, China. Their structures were elucidated by means of extensive spectroscopic analysis and by comparison of their data with reported values in literatures. Instead of the C-13 ester O-glycosyl found mostly in the titled plant growing in Thailand, compound 1 possessed a rare N-β-glucosamine-2-N-acetate moiety linked directly to the carbonyl at C-13 through an amido bond. Moreover, the acyl group at C-10 in 1 was (Z)-2-(2-hydroxyethyl)-pent-2-enedioyl group, instead of benzoic or p-hydroxybenzoic moieties found commonly in the reported norbisabolane sesquiterpenes. The known sesquiterpene 5 displayed stronger anti hepatitis B virus (HBV) activity with IC50 values of 1.69 ± 0.22 and 2.79 ± 0.69 μM towards HBV surface antigen (HBsAg) and HBV excreted antigen (HBeAg) secretion, respectively. [ABSTRACT FROM AUTHOR]

The fresh leaves of Metapanax delavayi (Araliaceae) have been used as a common wild vegetable for salad and soup, and also herbal tea by the local people living in its growing areas of Yunnan province, China. Detailed chemical investigation led to the identification of a new triterpenoid saponin, 3-O-α-L-arabinopyranosyl-28-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl-3β-hydroxyolean-12-ene-28,29-dioic acid (1) from the fresh leaves, together with 11 known compounds, including six triterpenoid saponins (2–7), two caffeoylquinic acid derivatives (8–9), and three flavonoid glycosides (10–12). Their structures were determined on the basis of spectroscopic analysis and acidic hydrolysis. Compounds 3–5 and 8–12 were isolated from M. delavayi for the first time. Moreover, the known saponins 3-O-β-D-xylopyranosyl-3β-hydroxyolean-12-ene-28,29-dioic acid (3) and yiyeliangwanoside IV (5) exhibited protective effects on HepG2 cells damaged by the alcohol intakes, at a concentration of 1.0 µg/mL. The results indicated M. delavayi is an ideal dietary vegetable and herbal tea with potential hepatoprotective activity. [ABSTRACT FROM AUTHOR]

Abstract: Panax notoginseng (Araliaceae) is a famous traditional Chinese medicine mainly cultivated in Yunnan and Guangxi provinces of China. Two new alkaloids, rigidiusculamide E (1) and [-(α-oxyisohexanoyl-N-methyl-leucyl)2-] (2), together with two known ones, (−)-oxysporidinone (3) and (−)-4,6′-anhydrooxysporidinone (4) were isolated from the mycelia culture of Fusarium tricinctum SYPF 7082, an endophytic fungus obtained from the healthy root of P. notoginseng. Their structures were determined on the basis of extensive spectroscopic analyses. Compounds 1-4 were tested for their inhibitory effects against NO production on Murine macrophage cell line, and the new compound 2 showed significant inhibitory activity on NO production with the IC50 value of 18.10 ± 0.16 μM.Graphical Abstract: [ABSTRACT FROM AUTHOR]

Black tea, rich in various and complex polyphenols, is one of the most popular beverages in the world due to its pleasant aroma and health benefits, such as alleviate hyperglycemia and antioxidant. The extensive investigation on the chemical constituents of Yunnan black tea 'Jin-Ya', produced from the leaf buds of Camellia sinensis var. assamica , led to the isolation and identification of 16 flavonoids including three new flavan-3-ols, namely theaflavoids A-C (1 – 3). Most of the isolates displayed obvious inhibitory activity on α -glucosidase with IC 50 values ranging from 1.11 to 24.7 μM. Notably, the new theaflavoids 1 – 3 showed much stronger inhibitory activity (IC 50 = 1.34, 1.11, and 4.57 μM, respectively) than those of the positive controls (acarbose and quercetin, IC 50 = 228 and 9.38 μM, respectively). In addition, the isolated flavonol glycosides 5 – 16 were evaluated for their antioxidant activities by DPPH and ABTS + radical scavenging assays. Those with galloyl group in molecular exhibited comparable free radical scavenging activities to the positive controls (ascorbic acid and Trolox), while most of the flavonol glycosides showed only moderate activities. The results indicated that Yunnan black tea 'Jin-Ya' is an ideal drink with hypoglycemic and antioxidant property, and is worthy of regular consumption. [Display omitted] • Three new (theaflavoids A-C) and 13 known flavonoids were isolated from black tea 'Jin-Ya'. • 'Jin-Ya' is produced from the leaf buds of Camellia sinensis var. assamica. • 15 flavonoids were isolated from black tea for the first time. • Most of the isolates showed obvious α -glucosidase inhibitory activity. • Some flavonoids showed stronger DPPH and ABTS + radical scavenging activities. [ABSTRACT FROM AUTHOR]