13C NMR spectra of pentacyclic triterpenoids--a compilation and some salient features

Occurrence, Biogenesis, and Synthesis of Biologically Active Carbazole Alkaloids

Privileged structures have been widely used as an effective template in medicinal chemistry for drug discovery. Chalcone is a common simple scaffold found in many naturally occurring compounds. Many chalcone derivatives have also been prepared due to their convenient synthesis. These natural products and synthetic compounds have shown numerous interesting biological activities with clinical potentials against various diseases. This review aims to highlight the recent evidence of chalcone as a privileged scaffold in medicinal chemistry. Multiple aspects of chalcone will be summarized herein, including the isolation of novel chalcone derivatives, the development of new synthetic methodologies, the evaluation of their biological properties, and the exploration of the mechanisms of action as well as target identification. This review is expected to be a comprehensive, authoritative, and critical review of the chalcone template to the chemistry community.

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Chalcone: A Privileged Structure in Medicinal Chemistry.

IT may occasion some surprise to those men of science who are ill-acquainted with India, and who so frequently express the view that Governments are unappreciative of the importance of science to learn that as far back as 1886 the Government of India arranged for Dr. George (later Sir George) Watt, professor of botany in the Presidency College, Calcutta, to prepare a "Dictionary of the Economic Products of India". The six volumes of this standard work were published during the years 1889-99. In 1908 Sir George Watt published a condensed version, "The Commercial Products of India". Whatever the defects of these 'dictionaries', they have been of inestimable value to all interested in Indian natural products. The Wealth of India A Dictionary of Indian Raw Materials and Industrial Products. Raw Materials, Vol. 1. Pp. xxvii+254+39 plates. 15 rupees ; 24s. Industrial Products, Part 1. Pp. xii+182+8 plates. 8 rupees ; 12s. (New Delhi : Council of Scientific and Industrial Research, 1948.)

The Wealth of India

http://www.zoranvolleyart.si/images/Mango/01.pdf

Medicinal properties of mangosteen (Garcinia mangostana).

The extract of Cinnamomum microphyllum showed strong antioxidant activity when it was tested against auto-oxidation of linoleic acid, superoxide, and DPPH radical scavenging activity Further detailed investigations of the plant constituents and bioactivity studies led to the isolation and identification of known compounds consisting of three lignans, a coumarin, an ester and β-sitosterol The structures of the compounds were determined using detailed spectroscopic analysis The lignans were found to possess a significant antioxidant activity when tested against the three assay systems

Chemical constituents and antioxidant activity of Cinnamomum microphyllum.

Extraction and chromatographic isolation of the hexane, chloroform and methanol extracts of stem bark of Calophyllum gracilipes has led to the isolation of a new xanthone, gracixanthone (1) and the known zeyloxanthanone (2) and trapezifolixanthone (3) together with three common sterols, namely stigmasterol, friedelin and lupeol. The structures of the compounds were elucidated and established by spectroscopic analysis and compared with the spectral data from literature. The cytotoxicity of the compounds was evaluated and zeyloxanthanone (2) exhibited strong activity towards five cell lines with IC50 values ranging at 8.00-26.00μM.

Xanthones from Calophyllum gracilipes and their cytotoxic activity.

The stem bark of Calophyllum inophyllum gave one new prenylated dipyranoxanthone inophinone (1), together with two other xanthones, inophyllin A (2) and caloxanthone B (3) and three common triterpenes, friedelin (4), stigmasterol (5) and betulinic acid (6). 1D and 2D NMR spectral data (1H, 13C, DEPT, COSY, HMBC & HMQC) were used to elucidate the structures of these compounds.

A new pyranoxanthone from the stem bark of Calophyllum inophyllum

Leaf extracts of Allamanda blanchetti, Allamanda cathartica, Allamanda cathartica ‘Alba’, Allamanda cathartica ‘Jamaican Sunset’ and Allamanda oenotheraefolia were screened for antifungal activities in vitro and in vivo. The results from all experiments proved that petroleum ether, chloroform
and methanol extracts of all plants possessed fungistatic or fungicidal properties on growth of Colletotrichum gloeosporioides which increased at higher extract concentrations. Scanning electron microscope observations showed that active extracts resulted in hyphal degradation where hyphae were retarded. A significantly lower disease incidence, severity, and index were observed in Allamanda
treated papaya fruits. Fruits coated with chloroform extracts of A. blanchetti A. cathartica ‘Alba’, and A. cathartica ‘Jamaican Sunset’ showed maximum reduction in anthracnose incidence and severity scores were always 1 (1-25%) and 0 (0%). Antifungal effects of the most effective extracts were
supported by the presence of chemical constituents indentified by GC-MS. Campesterol, �-sitosterol, stigmasterol, plumericin, squalene, and α-Tocopherol were detected as major compounds in Allamanda species that were possibly responsible for the antifungal activity.

Chemical composition and screening for antifungal activity of Allamanda spp. (Apocynaceae) crude extracts against Colletotrichum gloeosporioides, causal agent of anthracnose in papaya

Repeated separation and purification of fractions from the crude chloroform extract of Calophyllum inophyllum via column chromatography afforded five known xanthone caloxanthones A, B, C, macluraxanthone and pyranojacareubin. Structural elucidations and determination of the isolated compounds were supported by spectral analyses obtained by subjecting the compounds to various spectroscopic techniques. The chloroform extract, when tested against RAW264.7 cells for anti-inflammatory potentials, exhibited the most promising activity with an IC50 value of 14.81±0.04 µg/mL compared to moderate activities shown by the ethyl acetate and n-hexane extracts. Antimicrobial tests showed that the n-hexane and chloroform extracts acted moderately against Staphylococcus epidermidis S273 and Bacillus subtilis B145.

Mawardi Rahmani

Papers

Chemical constituents and antioxidant activity of Cinnamomum microphyllum.

Xanthones from Calophyllum gracilipes and their cytotoxic activity.

A new pyranoxanthone from the stem bark of Calophyllum inophyllum

Chemical composition and screening for antifungal activity of Allamanda spp. (Apocynaceae) crude extracts against Colletotrichum gloeosporioides, causal agent of anthracnose in papaya

Xanthones from Calophyllum inophyllum