A Study on Medicinal Plants from Malaysia Focused onAcalypha siamensisOliv.exGage. Isolation and Structure of a New Tetraterpene, Acalyphaser A

A Synthetic Butenolide Diterpene is now a Natural Product Isolated from Metaporana sericosepala, a Plant from the Madagascar Dry Forest [1a]

Antiproliferative bioassay-guided fractionation of the ethanolic extract of the endemic Madagascan plant Metaporana sericosepala led to the first natural product isolation of a butenolide diterpene, which was synthesized during an anti-inflammatory study in 1988. The structure of the compound was elucidated as 3-homofarnesyl-4-hydroxybutenolide (1) by analysis of its spectroscopic data, including 1D- and 2D-NMR data and chemical evidence. The once synthetic compound can now also be considered as a natural product. Compound 1 had modest antiproliferative activity towards the A2780 ovarian cancer cell line with an IC50 value of 8 μM.

Medicinal plants from the genus Acalypha (Euphorbiaceae)--a review of their ethnopharmacology and phytochemistry

ETHNOPHARMACOLOGICAL RELEVANCE

Acalypha is the fourth largest genus of the Euphorbiaceae family with approximately 450-570 species. Several Acalypha species are used as medicinal plants in Africa and in the Mascarene Islands. Almost every part of the plant including the leaves, stem and roots are used as traditional remedies to treat and manage a panoply of ailments. However, there is no updated compilation of traditionally important medicinal plants from the Acalypha genus. The present review therefore, endeavors to provide for the first time an updated compilation of documented ethnopharmacological information in relation to the ethnomedicinal, ethnoveterinary, zoopharmacognosy, phytochemistry and biological activities of medicinal plants from the Acalypha genus which can subsequently open new perspectives for further pharmacological research.

MATERIALS AND METHODS

A literature search was performed on Acalypha species using ethnobotanical text books and scientific databases such as Pubmed, Scopus, EBSCO, Google Scholar and other web sources such as records from PROTA, PROSEA, and Botanical Dermatology Database. The Plant List, International Plant Name index and Kew Botanical Garden Plant name databases were used to validate scientific names.

RESULTS AND DISCUSSION

Plants from Acalypha genus are traditionally used in the treatment and/or management of diverse ailments such as diabetes, jaundice, hypertension, fever, liver inflammation, schistosomiasis, dysentery, respiratory problems including bronchitis, asthma and pheumonia as well as skin conditions such as scabies, eczema and mycoses. Approximately 124 species were listed in ethnobotanical studies with some botanical description and others mentioned from different web sources. However, only 40 species have been included in the present review due to the unavailability of ethnopharmacological data on the remaining species. Among the 40 cited species, 30 were traditionally used for the treatment and/or management of approximately 70 human diseases or health conditions. Two species, Acalypha alnifolia and Acalypha fruticosa are used as insecticides and sand fly repellent respectively. Only 2 species (Acalypha fruticosa and Acalypha indica) are used in ethnoveterinary practice and have similar human and veterinary applications. In zoopharmacognosy, only Acalypha ornata has been mentioned. Natives from Africa, Central America, North America, Southern China, India, Bangladesh, Papua New Guinea and Mascarenes islands utilize Acalypha species as ethnomedicine. Traditionally used Acalypha species have been reported to possess at least one of the following biological activities: antimicrobial, anti-diabetic, antioxidant, anti-inflammatory, larvidal, pupicidal, hepatoprotective, anticancer, leishmanicidal, antihyperglycemic, antihypertensive, anti-venom, analgesic, anthelmintic, antiemetic, laxative, expectorant, diuretic, post-coital antifertility effects and wound healing. A total of 167 compounds have been identified from 19 species, with 16 from eight species were reported to be bioactive.

CONCLUSION

The present review represents 32.3% of species from the Acalypha genus and can be considered as the first compilation of ethnopharmacologically useful plants from this genus. There is a great potential to discover new biologically active phytochemicals from the Acalypha genus because only few species have been studied comprehensively. Therefore, the clinical evaluation of species from this genus is warranted in future studies to confirm the ethnomedicinal claims and for the safety approval of therapeutic applications.

Total synthesis of 7,11-cyclobotryococca-5,12,26-triene using an oxidative radical cyclization as a key step

An efficient total synthesis of the novel botryococcene-related hydrocarbon 7,11-cyclobotryococca-5,12,26-triene is reported that uses, as a key step, an oxidative radical cyclization of a 4-pentenyl malonate for the synthesis of a [3.3.0]-bicyclic gamma-lactone.

In vitro cytotoxic, antiprotozoal and antimicrobial activities of medicinal plants from Vanuatu

Sixty-three extracts obtained from 18 plants traditionally used in the South Pacific archipelago Vanuatu for the treatment of infectious diseases were screened for antimicrobial and antiprotozoal activities. In addition, the extracts were subjected to a detailed analysis on cytotoxic effects toward a panel of human cancer cell lines, designed as a smaller version of the NCI60 screen. Intriguingly, 15 plant extracts exhibited strong cytotoxic effects specific for only one cancer cell line. Extracts of the leaves of Acalypha grandis Benth. significantly affected Plasmodium falciparum without showing obvious effects against the other protozoa tested. The leaves of Gyrocarpus americanus Jacq. displayed significant activity against Trypanosoma b. brucei and the leaves of Tabernaemontana pandacaqui Lam. I as well as the stems of Macropiper latifolium (L.f.) against Trypanosoma cruzi. In contrast none of the extracts showed relevant antibacterial or antifungal activity.

Recombinant squalene synthase. synthesis of cyclopentyl non-head-to-tail triterpenes

Incubation of farnesyl diphosphate with recombinant yeast squalene synthase in the absence of NADPH gives a mixture of triterpene hydrocarbons and alcohols, including botryococcene-like compounds with 1'-3 linkages between the farnesyl units. One of these molecules has an unusual cyclopentane structure similar to those recently reported in plant extracts and lakebed sediments.