Biological screening of rain forest plot trees from Palawan Island (Philippines).

Study plots totaling 0.2 Ha were established in primary forest in the highlands of central Palawan Island, Philippines. Samples of various anatomical parts [typically leaf + twig (If/tw), stem bark (sb), and root (rt)] were collected from all tree species represented within the plots by individuals having a diameter at breast height > or = 10 cm. In all, 211 distinct samples were obtained from 68 tree species, representing 35 families (not including samples from 4 indeterminate species). Methanol extracts of these samples were tested in in vitro antiplasmodial, brine shrimp toxicity, and cytotoxicity assays. The following samples showed an IC50 < or = 10 microg/mL against either chloroquine-sensitive or chloroquine-resistant clones of Plasmodium falciparum: Acronychia laurifolia (sb), Agathis celebica (lf/tw), Aglaia sp. 1 (sb), Aglaia sp. 2 (lf/tw, rt), Bhesa sp. 1 (rt), Cinnamomum griffithii (lf/tw), Croton leiophyllus (rt), Dysoxylum cauliflorum (rt), Garcinia macgregorii (sb), Lithocarpus sp. 1 (rt, sb), Meliosma pinnata ssp. macrophylla (lf/tw, rt), Myristica guatteriifolia (lf/tw), Ochrosia glomerata (rt, sb), Swintonia foxworthyi (lf/tw), Syzygium sp. 1 (rt), Turpinia pomifera (rt), and Xanthophyllum flavescens (sb). Secondly, those samples which displayed > or = 50% immobilization of brine shrimp at 100 microg/mL were: Acronychia laurifolia (lf/tw/fruit, rt, sb), Agathis celebica (lf/tw, sb), Aglaia sp. 1 (lf/tw), Alphonsea sp. 1 (rt), Ardisia iwahigensis (lf/tw), Arthrophyllum ahernianum (lf/tw, rt, sb), Castanopsis cf. evansii (rt), Cinnamomum griffithii (lf/tw, rt), Croton argyratus (lf/tw), C. leiophyllus (lf/tw, rt), Dysoxylum cauliflorum (fruit, lf/tw, rt), Euonymus javanicus (rt), Glochidion sp. 1 (rt), Polyosma sp. 1 (rt), Symplocos polyandra (rt), Timonius gammillii (sb), and Xanthophyllum flavescens (rt). Lastly, samples which exhibited an IC50 < or = 20 microg/mL against one or more of the cancer cell lines employed (LU1, KB, KB-V1, P-388, LNCaP, or ZR-75-1) include: Acronychia laurifolia (lf/tw/fruit, rt, sb), Aglaia sp. 1 (sb), Aglaia sp. 2 (rt), Alphonsea sp. 1 (rt), Ardisia iwahigensis (lf/tw, rt, sb), Astronia cumingiana (sb), Croton argyratus (lf/tw, rt, sb), C. leiophyllus (lf/tw, rt), Dimorphocalyx murina (lf/tw, rt, sb), Lithocarpus caudatifolius (rt, sb), Litsea cf. sibuyanensis (rt), Syzygium cf. attenuatum (rt, sb), S. confertum (sb), Ternstroemia gitingensis (rt), and Ternstroemia sp. 1 (rt, sb).

Quinoline alkaloids from Acronychia laurifolia.

Bioassay-directed fractionation of a root extract of Acronychia laurifolia (Rutaceae) using the KB-V1+ human tumor cell line led to the isolation of six quinoline alkaloids. One of these alkaloids is novel, namely, 2,3-methylenedioxy-4,7-dimethoxyquinoline and the other five were identified as the known compounds, evolitrine, gamma-fagarine, skimmianine, kokusaginine and maculosidine. Two known bis-tetrahydrofuran lignans, sesamolin and yangambin, were also identified. The structure of the new alkaloid was determined by spectroscopic methods. All of the isolates were evaluated against a panel of human cancer cell lines; four of the alkaloids showed weak cytotoxic activity.

Isolation of gallic acid esters as antiplasmodial constituents of Swintonia foxworthyi (Anacardiaceae).

An extract of a leaf and twig sample from Swintonia foxworthyi demonstrated weak in vitro activity against two clones of Plasmodium falciparum. At the same time, the extract was inactive in cancer cell cytotoxicity assays. Bioassay-directed fractionation led to the isolation of methyl gallate as the principal antiplasmodial constituent; the compound demonstrated estimated IC(50) values of 2.0 and 3.5 µg/ml against the W2 and D6 clones of P. falciparum, respectively. Methyl digallate was also isolated from an active fraction and demonstrated estimated IC(50) values of 4.6 and 5.3 µg/ml against the W2 and D6 clones, respectively.

Guidelines and policies on collection of biological specimens in the Philippines. Philippine Congress, International Convention on Biodiversity.

In October, 1993, 16 months after the United Nations approved the International Convention on Biodiversity held in Rio de Janeiro, June, 1992, the Philippine Congress ratified and adopted the Convention. This is a manifestation of the full support of the Philippines for the principles and policies adopted by the UN body on the conservation of biodiversity, sustainable development of biological resources and equitable sharing of benefits between users and owners of biodiversity resources. The Philippine scientific community has long recognized the need for and importance of a national guideline and policy with regard to the collection of plants and animals in the Philippines for scientific or commercial purposes. A series of consultative meetings were held by representatives of government agencies, non-government organizations, private organizations, academic and private persons concerned with biodiversity conservation to formulate national guidelines that regulate the collection of plant and animal specimens in the country. Guidelines were unanimously adopted by various government agencies and academia and a Memorandum of Agreement (MOA) was signed on September 28, 1990. Very recently a new document was drafted, specifically to serve as a guideline for those who desire to undertake sample collecting in the Philippines for biodiversity prospecting. The document is now being reviewed by government departments and agencies and will be presented to the President of the Philippines for signing as an Executive Order (EO). Once signed, this EO will serve as a national policy for bioprospecting in the country. The Philippines is one of the countries in Southeast Asia that has endorsed the adoption of regional guidelines on the collection of plant and animal organisms for drug development. The ASEAN Agreement on the Conservation of Nature and Natural Resources (1985). The Manila Declaration (1992) and lately, the Melaka Accord (1994), all of which were signed by various countries in Asia, are manifestations of this interest.