A new triterpene from Luculia pinciana Hook

Specialised metabolites as chemotaxonomic markers of Coptosapelta diffusa, supporting its delimitation as sisterhood phylogenetic relationships with Rubioideae

From the aerial extracts of Coptosapelta diffusa (Champ. ex Benth.) Steenis, twenty-one compounds were isolated and identified by means of column chromatography and NMR and MS techniques, respectively. Amongst, ten ones were determined to be undescribed compounds including six seco-iridoid glucosides (1-6), 2-(hydroxymethyl)-1,2,3,4-tetrahydroanthracene-9,10-dione (7) and three guaiane-type sesquiterpenes (15-17). Compounds 7, 8 and 9 exhibited inhibitory activities against Staphylococcus aureus ATCC25923 with MIC of 8, 4 and 8 μg/mL. The use of 1-6 (iridoids), 7-14 (anthraquinones) and 15-17 (sesquiterpenes) as chemotaxonomic markers for this species was evidenced. Structurally, 7-14 are similar to those anthraquinones isolated from other species of the family Rubiaceae, confirming their close phylogenetic relationship. Whereas, these iridoids and sesquiterpenes with unique structures provided chemotaxonomic evidence to support the genus Coptosapelta (the tribe Coptosapelteae) as a sister of the subfamily Rubioideae. These results contrast with the general producing tendency of indole alkaloids by the species of the subfamily Cinchonoideae, and merit chemotaxonomic significance for the delimitation of Coptosapelta.

Volatile Organic Compounds Emissions from Luculia pinceana Flower and Its Changes at Different Stages of Flower Development

Luculia plants are famed ornamental plants with sweetly fragrant flowers, of which L. pinceana Hooker, found primarily in Yunnan Province, China, has the widest distribution. Solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) was employed to identify the volatile organic compounds (VOCs) emitted from different flower development stages of L. pinceana for the evaluation of floral volatile polymorphism. Peak areas were normalized as percentages and used to determine the relative amounts of the volatiles. The results showed that a total of 39 compounds were identified at four different stages of L. pinceana flower development, including 26 at the bud stage, 26 at the initial-flowering stage, 32 at the full-flowering stage, and 32 at the end-flowering stage. The most abundant compound was paeonol (51%–83%) followed by (E,E)-α-farnesene, cyclosativene, and δ-cadinene. All these volatile compounds create the unique fragrance of L. pinceana flower. Floral scent emission offered tendency of ascending first and descending in succession, meeting its peak level at the initial-flowering stage. The richest diversity of floral volatile was detected at the third and later periods of flower development. Principal component analysis (PCA) indicated that the composition and its relative content of floral scent differed throughout the whole flower development. The result has important implications for future floral fragrance breeding of Luculia. L. pinceana would be adequate for a beneficial houseplant and has a promising prospect for development as essential oil besides for a fragrant ornamental owing to the main compounds of floral scent with many medicinal properties.

Secondary metabolites from Rubiaceae species

This study describes some characteristics of the Rubiaceae family pertaining to the occurrence and distribution of secondary metabolites in the main genera of this family. It reports the review of phytochemical studies addressing all species of Rubiaceae, published between 1990 and 2014. Iridoids, anthraquinones, triterpenes, indole alkaloids as well as other varying alkaloid subclasses, have shown to be the most common. These compounds have been mostly isolated from the genera Uncaria, Psychotria, Hedyotis, Ophiorrhiza and Morinda. The occurrence and distribution of iridoids, alkaloids and anthraquinones point out their chemotaxonomic correlation among tribes and subfamilies. From an evolutionary point of view, Rubioideae is the most ancient subfamily, followed by Ixoroideae and finally Cinchonoideae. The chemical biosynthetic pathway, which is not so specific in Rubioideae, can explain this and large amounts of both iridoids and indole alkaloids are produced. In Ixoroideae, the most active biosysthetic pathway is the one that produces iridoids; while in Cinchonoideae, it produces indole alkaloids together with other alkaloids. The chemical biosynthetic pathway now supports this botanical conclusion.

Clinically useful anticancer, antitumor, and antiwrinkle agent, ursolic acid and related derivatives as medicinally important natural product

Medicinal plants are becoming an important research area for novel and bioactive molecules for drug discovery. Novel therapeutic strategies and agents are urgently needed to treat different incurable diseases. Many plant derived active compounds are in human clinical trials. Currently ursolic acid is in human clinical trial for treating cancer, tumor, and skin wrinkles. This review includes the clinical use of ursolic acid in various diseases including anticancer, antitumor, and antiwrinkle chemotherapies, and the isolation and purification of this tritepernoid from various plants to update current knowledge on the rapid analysis of ursolic acid by using analytical methods. In addition, the chemical modifications of ursolic acid to make more effective and water soluble derivatives, previous and current information regarding, its natural and semisynthetic analogs, focusing on its anticancer, cytotoxic, antitumor, antioxidant, anti-inflammatory, anti-HIV, acetyl cholinesterase, α-glucosidase, antimicrobial, and hepatoprotective activities, briefly discussion is attempted here for its research perspectives. This review article contains fourteen medicinally important ursolic acid derivatives and 351 references.