The Antiproliferative Effect of Chakasaponins I and II, Floratheasaponin A, and Epigallocatechin 3-O-Gallate Isolated from Camellia sinensis on Human Digestive Tract Carcinoma Cell Lines.

Acylated oleanane-type triterpene saponins, namely chakasaponins I (1) and II (2), floratheasaponin A (3), and their analogs, together with catechins-including (-)-epigallocatechin 3-O-gallate (4), flavonoids, and caffeine-have been isolated as characteristic functional constituents from the extracts of "tea flower", the flower buds of Camellia sinensis (Theaceae), which have common components with that of the leaf part. These isolates exhibited antiproliferative activities against human digestive tract carcinoma HSC-2, HSC-4, MKN-45, and Caco-2 cells. The antiproliferative activities of the saponins (1-3, IC50 = 4.4-14.1, 6.2-18.2, 4.5-17.3, and 19.3-40.6 µM, respectively) were more potent than those of catechins, flavonoids, and caffeine. To characterize the mechanisms of action of principal saponin constituents 1-3, a flow cytometric analysis using annexin-V/7-aminoactinomycin D (7-AAD) double staining in HSC-2 cells was performed. The percentage of apoptotic cells increased in a concentration-dependent manner. DNA fragmentation and caspase-3/7 activation were also detected after 48 h. These results suggested that antiproliferative activities of 1-3 induce apoptotic cell death via activation of caspase-3/7.

Quantitative Determination of Alkaloids in Lotus Flower (Flower Buds of Nelumbo nucifera) and Their Melanogenesis Inhibitory Activity.

A quantitative analytical method for five aporphine alkaloids, nuciferine (1), nornuciferine (2), N-methylasimilobine (3), asimilobine (4), and pronuciferine (5), and five benzylisoquinoline alkaloids, armepavine (6), norarmepavine (7), N-methylcoclaurine (8), coclaurine (9), and norjuziphine (10), identified as the constituents responsible for the melanogenesis inhibitory activity of the extracts of lotus flowers (the flower buds of Nelumbo nucifera), has been developed using liquid chromatography-mass spectrometry. The optimum conditions for separation and detection of these 10 alkaloids were achieved on a πNAP column, a reversed-phase column with naphthylethyl group-bonded silica packing material, with CH3CN-0.2% aqueous acetic acid as the mobile phase and using mass spectrometry equipped with a positive-mode electrospray ionization source. According to the protocol established, distributions of these 10 alkaloids in the petal, receptacle, and stamen parts, which were separated from the whole flower, were examined. As expected, excellent correlations were observed between the total alkaloid content and melanogenesis inhibitory activity. Among the active alkaloids, nornuciferine (2) was found to give a carbamate salt (2'') via formation of an unstable carbamic acid (2') by absorption of carbon dioxide from the air.

Quantitative Determination of Principal Alkaloid and Flavonoid Constituents in Wintersweet, the Flower Buds of Chimonanthuspraecox.

A quantitative analytical method has been-developed for four alkaloids (1-4), identified as constituents responsible for the melanogenesis inhibitory activity of the.extracts of wintersweet, the flower buds of Chimonanthus praecox (L.) Link (Calycanthaceae). Concurrently, a quantitative analytical protocol has been developed for five flavonoids (5-9), which also exhibited inhibitory activity. To approve the validity of the developed protocols, five extracts of the flower buds collected in Chinese market were evaluated. The optimum conditions of separation and detection of these alkaloids (1-4) and flavonoids (5-9) were achieved on a common ODS column using a MeOH-H20 mobile phase with different additives [Et2NH for alkaloids (1-4); acetic acid for flavonoids (5-9)]. The results. indicated that these assays were reproducible and precise, and could be readily utilized for evaluation of the melanogenesis inhibitory activity of -wintersweet on the basis of the content of the functional species. The principal flavonoid constituents (5-9) also exhibited lipid accumulation inhibitory activity.

Quantitative analysis of catechin, flavonoid, and saponin constituents in "tea flower", the flower buds of Camellia sinensis, from different regions in Taiwan.

Using the recently developed two analytical protocols, distributions were analyzed of five catechins (1-5), ten flavonoids (6-15), caffeine (16), and nine saponins (17-25) in 12 samples of flower buds of Camellia sinensis (L.) O. Kuntze, collected at different points in Taiwan. Characteristic tendencies with respect to the distribution of these constituents were observed according to the region of collection. Among the catechins, (-)-epigallocatechin 3-O-gallate (5) was the major constituent in all the samples. Notably, the content of 5 was higher in samples from the mountain regions in the middle and northern Taiwan than in samples from other regions. As for the principal flavonoids, the content of 10 was higher than that of 11 in most of the samples except those of Sijichun tea. For the saponin contents, the following trends were observed: (1) contents of chakasaponins I-III (17-19) were higher in samples from the mountain region in the middle and northern areas; and (2) contents of floratheasaponins A-F (20-25) were higher in the samples from central and southern areas.