Chong-Ren Yang

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.

Balanophora involucrata Hook.f. & Thomson (Balanophoraceae) is a parasite plant often growing on the roots of leguminous plants. The whole herb has been used medicinally for the treatment of irregular menstruation, cough, hemoptysis, traumatic injury and bleeding, dizziness and gastralgia in Yunnan Province, China. The 2,2-diphenyl-2-picrylhydrazyl (DPPH) assay on the 60% aq. acetone extract of the fresh whole plant of B. involucrata showed considerable radical-scavenging activity (SC₅₀ 15.3 μg/ml). Further purification on the extract led to the isolation of one new phenolic glycoside, sieboldin-3′-ketocarboxylic acid (1), and one new cyanogenic glycoside, proacacipetalin 6′-O-β-D-glucopyranoside (2), together with 26 known compounds including three 4″-O-galloyl and 2″,3″-O-(S)-hexahydroxydiphenoyl (HHDP) derivatives of dihydrochalcone glucosides, seven hydrolyzable tannins, and alkane glycosides. The cyanogenic compound isolated from the Balanophoraceae family for the first time might be a signal molecule between B. involucrata and its hosts. The free-radical-scavenging activity of the isolated compounds was also examined by DPPH assay.

To investigate the antiviral activities of three kinds of extracts from the fruit of Eucalyptus maidenii against herpes simplex virus typel and Hepatitis B Virus. Cytotoxicity of extracts on Vero cell lines were estimated using MTT method and anti-HSV-1 activity was observed and determined with CPE and plaque reduction assay. The inhibitory effects of extracts on HBsAg and HBeAg secretion in HepG2.2.15 cell culture were detected using ELISA. Aqueous extract (pl8-E3) had conspicuous anti-HSV-1 activity, the IC50 was 126.77 microg/mL,but the EtOAc extracts( pl8-E1 )and MeOH extracts (pl8-E2) showed little anti-HSV-1 activity. None of these extracts had significant inhibitory eflect on HBsAg and HBeAg secretion in HepG2.2.15 cell culture. Aqueous extract(p18-E3) from the fruit of Eucalyptus maidenii has conspicuous anti-HSV-1 activity. It could inactivate virus directly,and inhibit virus attachment,but had no influence on virus penetration. The mechanism that p18-E3 inactivates virus might involve in viral envelope alteration.

Background: Panax notoginsengis an important Chinese medicinal plant. Dammarene-type triterpenoid saponins are main pharmacologically effective compounds inP. notoginseng. This study aims to investigate the formation and accumulation of saponins inP. notoginsengroots during germination and juvenile stage.Methods: P. notoginsengseeds were collected and stored in wet sand. After germination, the seedlings were transplanted into a soil nursery bed and cultivated for one year. During this period, samples were collected every month and the concentrations of ginsengnosides Rg₁, Re, Rb₁, Rd and notoginsengnoside R₁were determined by HPLC.Results: There was little saponin in theP. notoginsengseed. The chemical composition of seed was different from that of root. After germination, Rb₁, Rg₁, Re, Rd and R₁appeared successively in the seedling root. And in the five-month-old root, all these five main saponins came into existence. The accumulation of saponins inP. notoginsengroot was affected by seasons.Conclusion: The accumulation of saponins showed a time-dependent increase after germination ofP. notoginseng.

Magnified image Two new acylated secoiridoid glucosides, 4′‐acetyl‐6′‐{[2‐hydroxy‐3‐(1‐β‐D‐glucopyranosyloxy)]benzoyloxy}sweroside and 3′,4′‐diacetyl‐6′‐{[2‐hydroxy‐3‐(1‐β‐D‐glucopyranosyloxy)]benzoyloxy}swertiamarin, named gentistraminosides A (1) and B (2), were isolated from the MeOH extract of Gentiana straminea Maxim (Gentianaceae), together with twelve known ones, including eight iridoid and secoiridoid glucosides, macrophylloside A (3), loganic acid (4), secologanic acid (5), swertiamarin (6), gentiopicroside (7), loganic acid methyl ester (8), 6′‐O‐β‐D‐glucopyranosyl gentiopicroside (9), and loganic acid 11‐O‐β‐D‐glucopyranosyl ester (10), one flavone C‐glucoside, isovitexin (11), one chromenecarboxylic acid glycosyl ester, macrophylloside D (12), and two triterpenoids, 1α,2α,3β,24‐tetrahydroxyolean‐12‐en‐28‐oic acid (13), and 3β,6α,24‐trihydroxyolean‐12‐en‐28‐oic acid (14). Their structures were determined by means of detailed spectroscopic (NMR and MS) analysis.